# Rosetexwool Insulation Refractory Co., Ltd. — full content > High-performance ceramic fiber insulation products and refractory solutions for industrial applications up to 1600°C. Rosetexwool Insulation Refractory Co., Ltd. is a manufacturer of ceramic fiber blankets, boards, papers, modules, and custom-shaped insulation products. Based in China, serving global industrial markets including petrochemical, steel, power generation, and aerospace. Source: https://www.rosetexwool.net Companion navigation file: https://www.rosetexwool.net/llms.txt ## Company - Company name: Rosetexwool Insulation Refractory Co., Ltd. - Legal name: Rosetexwool Insulation Refractory Co., Ltd. - Founded: 1982 - Address: Zhengzhou, Henan Province, China - Email: sales@rosetexwool.com - Phone: +86 13674954566 - WhatsApp: +86 13674954566 ## Products ### Refractory Ceramic Fiber Blanket — Ceramic Fiber Blanket Insulation URL: https://www.rosetexwool.net/products/ceramic-fiber-blanket/ Category: Ceramic Fiber Summary: Refractory ceramic fiber blanket, also marketed as ceramic fire blanket — Class A non-combustible insulation rated 1100–1430°C. Ceramic blanket insulation for furnaces, boilers, kilns & pipe wrap. Refractory ceramic fiber blanket (also called ceramic fire blanket in trade literature) is a high-performance thermal insulation material engineered from spun alumina-silicate fibers. It is a lightweight, flexible refractory ceramic fiber blanket made from molten raw materials drawn into continuous fibers, then needled into a uniform, dust-controlled blanket. As a refractory ceramic fiber insulation product, it delivers excellent thermal stability across the widest service range of any non-combustible insulation blanket. This refractory ceramic fiber blanket is rated for continuous use at 1100°C with a maximum service temperature up to 1430°C depending on grade. Standard (ST) and High-Purity (HP) grades reach 1260°C, High-Alumina (HA) handles 1360°C, and Zirconia (HZ) extends to 1430°C. Thermal conductivity remains low at 0.04–0.12 W/(m·K) even at elevated temperatures. Available in densities from 64 to 200 kg/m³, each ceramic fiber blanket is also commonly referred to simply as ceramic blanket and forms the basis of most high-temperature insulation blanket systems in industrial plants. The ceramic fiber blanket insulation is widely used as a refractory lining for industrial furnaces and kilns (including ceramic blanket insulation grades for reformer, cracker, and ethylene furnaces in petrochemical plants), boiler and combustion-chamber walls, high-temperature pipe wrap, expansion joints, door seals, and removable thermal pads. A ceramic fire blanket is also installed in shipyards, welding shops, and offshore platforms as an active fire-protection blanket for hot-work operations. Compared with rock wool blanket, calcium silicate board, and high-temperature foam glass, refractory ceramic fiber blanket offers the highest temperature rating per unit weight, lowest thermal conductivity, and the best thermal-shock resistance. For applications above 1000°C where rock wool and calcium silicate are unsuitable, refractory ceramic fiber blanket (or ceramic fire blanket, for hot-work use) is the industry-standard refractory ceramic fiber insulation choice — backed by ISO 9001 manufacturing and CE / ASTM certification. Manufacturer & Supplier Rosetexwool is a ceramic fiber blanket manufacturer and supplier serving more than 60 countries since 1982. Every ceramic fiber blanket is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives ceramic fiber tape — Heat resistant tape to 1260 °C that wraps pipework, valves and hoses cleanly, with useful dielectric strength alongside the thermal protection. ceramic fiber modules — Pre-compressed folded modules that install far faster than layered blanket, with lower heat storage and measurable fuel savings per cycle. wired rockwool blanket — Stone wool blanket stitched to galvanised wire mesh so it can be mechanically fixed to large tanks, boilers and ductwork. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Low thermal conductivity - Good thermal stability - Thermal shock resistance - Good tensile strength - Noise reduction - Fire protection Applications: - Building fire protection (curtain walls, cable shafts) - Boilers & combustion chambers - High-temperature furnace bodies - Kiln linings - Petrochemical equipment insulation - Refractory lining for industrial furnace & kiln - Ceramic fire blanket for welding protection & shipyard insulation Specifications: - Density: 96/128/160 kg/m³ - Raw Material: Spun ceramic fiber bulk - Thickness: 10-50mm - Asbestos: 100% Non-Asbestos - Size: 7200/3600×610/1220×10-50mm - Classification Temperature: 1100 / 1260 / 1360 / 1400 / 1430℃ (by grade) - Thermal Conductivity: ≤ 0.03 W/(m·K) @ 800℃ - Package Size: 7200 / 3600 × 610 / 1220 × 10–50 mm Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100°C to 1430°C, depending on the grade. Standard (ST) and High-Purity (HP) grades are rated for 1260°C, while High-Alumina (HA) handles 1360°C and Zirconia (HZ) reaches 1430°C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al₂O₃) content and temperature rating. COM (1100°C) is the economy grade. ST (1260°C) is the standard industrial grade. HP (1260°C) offers higher purity with lower shot content. HA (1360°C) has higher alumina for superior thermal stability. HZ (1430°C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. Q: What is a ceramic fire blanket, and is it the same as a ceramic fiber blanket? A: A **ceramic fire blanket** is the same alumina-silicate needled blanket as a ceramic fiber blanket, supplied for welding, foundry and fire-protection duties. The 'fire blanket' name reflects its non-combustible, high-temperature character (rated 1100–1430°C by grade), not a different material. We stock it in roll, piece and quilted welding-blanket formats. Q: What is refractory ceramic fiber blanket used for? A: **Refractory ceramic fiber blanket** (RCF blanket) is specified where sustained high heat is present: furnace and kiln linings, boiler and combustor insulation, expansion joints, refractory backup and pipe wrapping up to 1430°C. Its low thermal mass cuts heat loss and shortens furnace cycling versus firebrick. Q: Is ceramic fiber blanket insulation the same as ceramic blanket insulation? A: Yes. 'ceramic fiber blanket insulation' and 'ceramic blanket insulation' describe the same product — 'ceramic blanket' is simply the short form of 'ceramic fiber blanket'. Both are needled, non-combustible alumina-silicate blankets rated 1100–1430°C by grade. ### Refractory Ceramic Fiber Board for High Temperature Insulation URL: https://www.rosetexwool.net/products/ceramic-fiber-board/ Category: Ceramic Fiber Summary: Refractory ceramic fiber board for high temperature insulation up to 1430C. Rigid, easy to cut, multiple densities and grades. Factory direct pricing. Refractory Ceramic Fiber Board for High Temperature Insulation Also referred to as ceramic fiber insulation board or simply ceramic insulation board, this rigid refractory product is the industry standard for high temperature furnace and kiln lining. Our refractory ceramic fiber board is a rigid high temperature insulation board engineered for continuous service up to 1430C. Vacuum-formed from high-purity alumina-silicate ceramic fiber bulk, it delivers the structural rigidity that blanket or paper cannot provide, making it the preferred refractory ceramic fiber board for furnace linings, kiln hot-face insulation, and high temperature process equipment. Why Choose This High Temperature Ceramic Fiber Board - High temperature rating up to 1430C - six grades (COM/ST/HP/HA/Zir-Alu/HZ) cover every operating range from 1100C economy to 1430C zirconia-stabilised service. - Rigid and machinable - cuts cleanly with a handsaw or knife, holds shape under compression, ideal for custom refractory linings and baffle boards. - Low thermal conductivity - 0.12-0.18 W/(m.K) at 800C, outperforms calcium silicate and insulating firebrick at equivalent density. - Low shrinkage and excellent thermal stability - maintains dimensional integrity through thermal cycling, critical for high temperature ceramic fiber board used as furnace hot-face. - 100% asbestos-free - classified non-carcinogenic under EU Directive 97/69/EC, safe to handle with standard PPE. High Temperature Ceramic Fiber Board Applications This refractory ceramic fiber board is widely used as: - Hot-face and backup insulation in industrial furnaces and kilns - High temperature furnace lining for heat treatment equipment - Petrochemical heater and cracker lining - LNG and liquid nitrogen cold-box insulation - Refractory baffle, burner block, and combustion chamber lining - Expansion joint and door seal in high temperature ducting Material Composition Made from high-purity alumina-silicate ceramic fiber bulk, vacuum-formed into rigid sheets. Six standard grades are available depending on alumina (Al2O3) content and zirconia stabilisation: COM (44% Al2O3, 1100C), ST (46% Al2O3, 1260C), HP (47-49% Al2O3, 1260C), HA (52-55% Al2O3, 1360C), Zir-Alu (45-46% Al2O3 + 5-7% ZrO2, 1200C), and HZ (39-40% Al2O3 + 15-17% ZrO2, 1430C). For a comparison of grades and help selecting the right refractory ceramic fiber board for your application, see the specification table below or contact our technical team. Manufacturer & Supplier Rosetexwool is a ceramic fiber board manufacturer and supplier serving more than 60 countries since 1982. Every ceramic fiber board is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives ceramic fiber special shaped — Vacuum-formed shapes produced to your drawing, so burner blocks, ladle covers and complex furnace geometries arrive ready to fit. polycrystalline mullite fiberboard — Ultra-high temperature board to 1900 °C with exceptional thermal stability and very low shrinkage at the top of the range. flexible silicate insulation — Bends around curved shells and irregular surfaces without cracking, which rigid board cannot do without expensive fabrication. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Excellent thermal stability - Low thermal conductivity - Good sound insulation - Low shrinkage - Good fiber resilience - Easy installation Applications: - Kiln lining insulation - LNG and liquid nitrogen storage tanks - Heat treatment equipment lining - Refractory lining for industrial furnaces - High temperature furnace backup insulation - Petrochemical heater and cracker lining Specifications: - Density: 260-320 kg/m3 - Thickness: 10-50mm - Size: 1200x1000mm / 1000x600mm - Compressive Strength: 0.5 MPa - Asbestos: 100% Non-Asbestos - Temperature Rating: 1100-1430C - Thermal Conductivity: 0.12-0.18 W/(m.K) @800C - Al2O3 Content: 44-55% Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100C to 1430C, depending on the grade. Standard (ST) and High-purity (HP) grades are rated for 1260C, while High-Alumina (HA) handles 1360C and Zirconia (HZ) reaches 1430C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al2O3) content and temperature rating. COM (1100C) is the economy grade. ST (1260C) is the standard industrial grade. HP (1260C) offers higher purity with lower shot content. HA (1360C) has higher alumina for superior thermal stability. HZ (1430C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. Q: What is refractory ceramic fiber board? A: Refractory ceramic fiber board is a rigid high temperature insulation board made from alumina-silicate ceramic fiber bulk, vacuum-formed into dense sheets rated for continuous service up to 1430C. It combines low thermal conductivity with structural rigidity, making it ideal for refractory linings in furnaces, kilns, and high temperature process equipment where board-form insulation is required. Q: What is the high temperature rating of ceramic fiber board? A: Our refractory ceramic fiber board is rated for continuous operating temperatures from 1100C (COM grade) up to 1430C (HZ zirconia grade). The standard 1260C grade (ST/HP) covers most industrial furnace applications, while HA (1360C) and HZ (1430C) grades serve high temperature process equipment such as steel reheat furnaces, ceramic kilns, and petrochemical crackers. Q: How is ceramic fiber board installed? A: Refractory ceramic fiber board can be cut with a handsaw or utility knife and secured with high temperature anchors, ceramic pins, or stud welding. For furnace lining, install as a hot-face or backup layer with joints staggered. For pipe insulation, shape to curvature and band with stainless steel straps. Full installation guidance is provided with every order. ### Ceramic Fiber Board Alternative URL: https://www.rosetexwool.net/products/ceramic-fiber-board-alternative/ Category: Ceramic Fiber Summary: Cost-effective insulation board from rare earth cotton for medium-temperature applications up to 600℃. Manufactured from rare earth cotton (magnesium silicate), offering cost-effective insulation for medium-temperature applications with good thermal insulation performance. What Is Ceramic Fiber Board? Ceramic fiber board is a rigid, dimensionally stable panel made by wet-forming ceramic fibre, providing a board alternative to blanket where a self-supporting, machinable hot-face or backup surface is needed. Key Technical Specifications Property | Value | Maximum service temperature | classification 1260–1430°C; service up to 1100–1250°C | Density | 280–400 kg/m³ | Thermal conductivity | 0.08–0.15 W/(m·K) at 600–1000°C mean | Standard thickness | 6–100 mm | Standard dimensions | 600×900 mm, 1000×1200 mm and custom | Fire classification | Non-combustible (ceramic fibre, asbestos-free) | Composition | high-purity alumino-silicate (Al₂O₃ + SiO₂) blown fibre, no organic binder | Standards | ASTM C892, ASTM C1086, ISO 10635, EN 10964 | Properties & Advantages - Rigid, self-supporting and easy to machine - Low heat storage and thermal conductivity - Stable at high temperature, low shrinkage - Good dielectric and chemical resistance - Asbestos-free and clean to cut Typical Applications - Hot-face backup and furnace walls - Kiln liners and furnace doors - Combustion-chamber and burner liners - Electrical and thermal barrier panels Installation & Handling Cut with a carbide blade or jigsaw, seat against the lining and fix with ceramic-fibre anchors or refractory mortar. Support vertically to avoid load on thin sections. Standards & Compliance Manufactured to ASTM C892, ASTM C1086, ISO 10635, EN 10964 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a ceramic fiber board manufacturer and supplier serving more than 60 countries since 1982. Every ceramic fiber board is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives ceramic fiber plus blanket — An upgraded blanket with lower shot content and improved tensile strength, aimed at linings where consistency matters more than price. ceramic fiber cloth — Woven refractory cloth reinforced with fibreglass filament, flexible enough to sew into curtains and removable covers while holding its strength at temperature. rockwool pipe insulation — Pre-formed stone wool pipe sections for continuous service to 650 °C, factory-cut to standard diameters so coverage stays uniform. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Cost-effective - Good thermal insulation - Lightweight - Good workability - Stable at medium temperatures - Asbestos-free Applications: - Medium-temperature furnace insulation - Industrial equipment thermal barriers - Building insulation - Cost-sensitive thermal management Specifications: - Raw Material: Rare Earth Cotton - Working Temp.: 600℃ - Size: 1000×500×50mm / 300×600×50mm - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100°C to 1430°C, depending on the grade. Standard (ST) and High-Purity (HP) grades are rated for 1260°C, while High-Alumina (HA) handles 1360°C and Zirconia (HZ) reaches 1430°C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al₂O₃) content and temperature rating. COM (1100°C) is the economy grade. ST (1260°C) is the standard industrial grade. HP (1260°C) offers higher purity with lower shot content. HA (1360°C) has higher alumina for superior thermal stability. HZ (1430°C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. ### Ceramic Fiber Bulk URL: https://www.rosetexwool.net/products/ceramic-fiber-bulk/ Category: Ceramic Fiber Summary: Loose ceramic fiber bulk for filling, vacuum-formed shapes manufacturing, and custom insulation applications. Raw form of ceramic fiber produced through melting and fiberizing. Used as base material for manufacturing other ceramic fiber products and as loose-fill insulation for complex spaces and cavities. What Is Ceramic Fiber Bulk (Loose Wool)? Ceramic fiber bulk is the loose, un-bonded fibre form of ceramic fibre — the raw material for modules, vacuum-formed shapes and castable reinforcement, and a practical fill for cavities and complex voids. Key Technical Specifications Property | Value | Maximum service temperature | classification 1260°C; service up to 1100°C | Density | 60–200 kg/m³ (loose, as packed) | Thermal conductivity | 0.05–0.12 W/(m·K) (as loose fill) | Standard thickness | loose / chopped fibre | Standard dimensions | compressed bales or bags | Fire classification | Non-combustible (ceramic fibre, asbestos-free) | Composition | high-purity alumino-silicate (Al₂O₃ + SiO₂) blown fibre, no organic binder | Standards | ASTM C892, ASTM C1086, ISO 10635, EN 10964 | Properties & Advantages - Conforms to irregular cavities and voids - Low thermal conductivity as a fill - Base material for modules and shapes - Reinforces castables and coatings - Asbestos-free, low shot content Typical Applications - Cavity and complex-void filling - Feedstock for modules and special shapes - Castable and mortar reinforcement - Filtration and high-temp packing Installation & Handling Place loosely without over-compression to keep the insulating air fraction; for casting, blend the chopped fibre evenly into the matrix. Standards & Compliance Manufactured to ASTM C892, ASTM C1086, ISO 10635, EN 10964 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a ceramic fiber bulk (loose wool) manufacturer and supplier serving more than 60 countries since 1982. Every ceramic fiber bulk (loose wool) is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives ceramic fiber blanket — Needled refractory blanket rated 1100–1430 °C with very low thermal conductivity and the thermal shock resistance that rapid furnace cycling demands. ceramic fiber board — Rigid refractory board to 1430 °C in several densities and grades, cuttable with ordinary tools and stable enough to hold tight tolerances in place. calcium silicate pipe sections — Built for industrial steam and high-temperature process piping where the insulation has to survive thermal cycling and still be removable for inspection. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Excellent thermal insulation - Low thermal conductivity - Good thermal shock resistance - Multiple temperature grades - 100% inorganic, non-combustible - Easy to pack irregular spaces Applications: - Raw material for vacuum-formed products - Loose fill furnace insulation - Expansion joint filling - Ceramic fiber textile manufacturing Specifications: - Form: Loose cotton / Bulk fiber - Temperature: 1100-1430℃ - Fiber Diameter: 2-4 μm - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100°C to 1430°C, depending on the grade. Standard (ST) and High-Purity (HP) grades are rated for 1260°C, while High-Alumina (HA) handles 1360°C and Zirconia (HZ) reaches 1430°C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al₂O₃) content and temperature rating. COM (1100°C) is the economy grade. ST (1260°C) is the standard industrial grade. HP (1260°C) offers higher purity with lower shot content. HA (1360°C) has higher alumina for superior thermal stability. HZ (1430°C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. ### Ceramic Fiber Cloth URL: https://www.rosetexwool.net/products/ceramic-fiber-cloth/ Category: Ceramic Fiber Summary: High temperature woven ceramic fiber cloth reinforced with fiberglass filament for thermal insulation and fire protection. Woven from high-quality ceramic fiber yarn reinforced with fiberglass filament and optional stainless steel wire. Excellent high-temperature resistance, flexibility, and handling characteristics. What Is Ceramic Fiber Cloth? Ceramic fiber cloth is a woven fabric of ceramic-fibre yarn (often with fibreglass or steel-wire weft) that stays flexible at high temperature, used for welding blankets, curtains and removable insulation jackets. Key Technical Specifications Property | Value | Maximum service temperature | classification 1260°C; service up to 1100°C | Density | woven yarn basis; cloth 2–4 mm thick | Thermal conductivity | 0.10–0.18 W/(m·K) (as fabric layer) | Standard thickness | 2–4 mm | Standard dimensions | widths up to 1000 mm; rolls 30 m typical | Fire classification | Non-combustible (ceramic fibre, asbestos-free) | Composition | high-purity alumino-silicate (Al₂O₃ + SiO₂) blown fibre, no organic binder | Standards | ASTM C892, ASTM C1086, ISO 10635, EN 10964 | Properties & Advantages - Flexible, drapeable high-temp fabric - Resists flame, spatter and thermal shock - Wire/fibreglass weft adds strength - Forms removable, reusable jackets - Asbestos-free, chemical-resistant Typical Applications - Welding blankets and safety curtains - Expansion-joint and flange covers - Removable equipment insulation jackets - Cable and hose heat shielding Installation & Handling Drape or wrap over the surface and secure with high-temperature lacing wire or fasteners; overlap seams for continuous coverage. Standards & Compliance Manufactured to ASTM C892, ASTM C1086, ISO 10635, EN 10964 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a ceramic fiber cloth manufacturer and supplier serving more than 60 countries since 1982. Every ceramic fiber cloth is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives ceramic fiber bulk — Loose bulk fibre supplied for filling cavities and expansion joints, and as the raw material for vacuum-formed shapes and ceramic fibre textiles. low shot ceramic fiber blanket — Fewer unfiberised shot particles mean more uniform density, cleaner handling on site and less dust during installation. rockwool insulation blanket — Flexible stone wool blanket for continuous service to 650 °C, conforming to curved and irregular surfaces while keeping thermal performance uniform. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Excellent high-temperature resistance - Good flexibility - Low thermal conductivity - Good chemical stability - Reinforced with fiberglass/steel - Non-combustible, asbestos-free Applications: - Furnace curtains - Expansion joint packing - Removable insulation covers - Welding protection blankets - Cable fire protection wraps Specifications: - Thickness: 1.5/2/3/5mm - Width: 1000 / 1500mm - Temperature: Up to 1260℃ - Reinforcement: Fiberglass / Stainless steel - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100°C to 1430°C, depending on the grade. Standard (ST) and High-Purity (HP) grades are rated for 1260°C, while High-Alumina (HA) handles 1360°C and Zirconia (HZ) reaches 1430°C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al₂O₃) content and temperature rating. COM (1100°C) is the economy grade. ST (1260°C) is the standard industrial grade. HP (1260°C) offers higher purity with lower shot content. HA (1360°C) has higher alumina for superior thermal stability. HZ (1430°C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. ### Ceramic Fiber Modules URL: https://www.rosetexwool.net/products/ceramic-fiber-modules/ Category: Ceramic Fiber Summary: Pre-compressed folded modules for industrial furnace linings. Faster installation, lower heat storage, superior energy savings. Made from ceramic fiber acupuncture blanket, processed in dedicated machines. Folded modules are directly fixed to industrial furnace shell plates by various anchorages. What Is Ceramic Fiber Modules? Ceramic fiber modules are pre-compressed folded blankets anchored to a metal backing, enabling fast, uniform furnace-wall lining with low heat storage and rapid heat-up/cool-down. Key Technical Specifications Property | Value | Maximum service temperature | classification 1260–1430°C; service up to 1100–1250°C | Density | 192–320 kg/m³ (as module) | Thermal conductivity | ≤0.153 W/(m·K) at 500°C mean | Standard thickness | 150–300 mm (module depth) | Standard dimensions | 300×300 mm typical face; custom | Fire classification | Non-combustible (ceramic fibre, asbestos-free) | Composition | high-purity alumino-silicate (Al₂O₃ + SiO₂) blown fibre, no organic binder | Standards | ASTM C892, ASTM C1086, ISO 10635, EN 10964 | Properties & Advantages - Rapid, uniform furnace lining - Low heat storage — fast cycles - Anchor options for new or worn linings - Good thermal-shock resistance - Reduced installation time vs brick Typical Applications - Industrial furnace and kiln walls - Heater and reformer linings - Annealing and heat-treat furnaces - Retrofit of worn refractory linings Installation & Handling Fix modules to the shell with the specified anchors (welded stud, threaded or marshal). Butt module faces tightly so the hot face is continuous; stagger rows to avoid through-joints. Standards & Compliance Manufactured to ASTM C892, ASTM C1086, ISO 10635, EN 10964 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a ceramic fiber modules manufacturer and supplier serving more than 60 countries since 1982. Every ceramic fiber modules is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives ceramic fiber rope — Twisted refractory rope to 1260 °C for door seals, flange gasketing and expansion joint packing that has to stay compressible at heat. ceramic fiber board alternative — A cost-effective board made from rare earth cotton for medium-temperature work to 600 °C where full refractory grade would be over-specification. rock wool strips — Narrow stone wool strips cut to precise dimensions for joints, gaps and perimeter fire barriers where full boards will not fit. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Faster temperature cycling - Lower heat storage - Lower fuel costs - Increased productivity - Easy to install - Easy repairs - Thermal shock resistance Applications: - High-temperature reactors - Power generation turbines - Industrial furnaces Specifications: - Density: 160-260 kg/m³ - Size: 300/600×300×200-350 mm - Packing: Plastic bag + Carton/Pallet Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100°C to 1430°C, depending on the grade. Standard (ST) and High-Purity (HP) grades are rated for 1260°C, while High-Alumina (HA) handles 1360°C and Zirconia (HZ) reaches 1430°C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al₂O₃) content and temperature rating. COM (1100°C) is the economy grade. ST (1260°C) is the standard industrial grade. HP (1260°C) offers higher purity with lower shot content. HA (1360°C) has higher alumina for superior thermal stability. HZ (1430°C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. ### Ceramic Fiber Paper URL: https://www.rosetexwool.net/products/ceramic-fiber-paper/ Category: Ceramic Fiber Summary: Thin, flexible ceramic fiber paper for gaskets, expansion joints, and high-temperature sealing applications. Manufactured from high-purity ceramic fibers with organic binder. Uniform thickness, smooth surface, excellent flexibility, and good handling strength for high-temperature gaskets and thermal barriers. What Is Ceramic Fiber Paper? Ceramic fiber paper is a thin, flexible sheet produced by wet-forming ceramic fibre with a small amount of organic binder, giving it the handle of paper with refractory-grade temperature resistance for gaskets, seals and electrical insulation. Key Technical Specifications Property | Value | Maximum service temperature | classification 1260°C; continuous service up to 1100°C | Density | 180–220 kg/m³ (as sheet) | Thermal conductivity | 0.06–0.10 W/(m·K) | Standard thickness | 0.5–3 mm | Standard dimensions | sheets/rolls 600×1200 mm, 1000×1000 mm | Fire classification | Non-combustible (ceramic fibre, asbestos-free) | Composition | high-purity alumino-silicate (Al₂O₃ + SiO₂) blown fibre, no organic binder | Standards | ASTM C892, ASTM C1086, ISO 10635, EN 10964 | Properties & Advantages - Thin, flexible and easy to cut or stamp - Low thermal conductivity and heat storage - Good dielectric strength at temperature - Resilient seal against flame and gas paths - Asbestos-free, low shot content Typical Applications - Gaskets and high-temperature seals - Refractory backup and expansion joints - Electrical and thermal barrier laminates - Brazing and heat-treat separation Installation & Handling Cut with a sharp blade or die. For seals, compress lightly between flanges; multiple plies can be built up where a thicker barrier is needed. Standards & Compliance Manufactured to ASTM C892, ASTM C1086, ISO 10635, EN 10964 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a ceramic fiber paper manufacturer and supplier serving more than 60 countries since 1982. Every ceramic fiber paper is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives high strength ceramic fiber blanket — Chosen for critical petrochemical equipment and precision heating plant where the blanket has to hold together through repeated thermal cycling. ceramic rope gasket — A direct replacement for legacy asbestos rope seals, sized to fit existing grooves without modifying the door or flange. rock wool blanket with glass mesh — Stone wool blanket faced with glass fibre mesh for a tougher surface that survives handling and gives a smoother finished appearance. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Uniform thickness - Excellent flexibility - Low thermal conductivity - Good dielectric strength - Thermal shock resistance - Easy to cut and shape Applications: - High-temperature gaskets - Expansion joints - Thermal barriers in automotive - Backup insulation - Electrical insulation Specifications: - Thickness: 0.5-6mm - Width: 610mm / 1000mm - Temperature: Up to 1260℃ - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100°C to 1430°C, depending on the grade. Standard (ST) and High-Purity (HP) grades are rated for 1260°C, while High-Alumina (HA) handles 1360°C and Zirconia (HZ) reaches 1430°C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al₂O₃) content and temperature rating. COM (1100°C) is the economy grade. ST (1260°C) is the standard industrial grade. HP (1260°C) offers higher purity with lower shot content. HA (1360°C) has higher alumina for superior thermal stability. HZ (1430°C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. ### Ceramic Fiber Plus Blanket URL: https://www.rosetexwool.net/products/ceramic-fiber-plus-blanket/ Category: Ceramic Fiber Summary: Advanced ceramic fiber blanket with improved strength and lower shot content for demanding applications. Advanced blanket with improved fiber quality, lower shot content, better tensile strength, and more consistent density for superior insulation in critical high-temperature applications. What Is Ceramic Fiber Blanket (High-Purity)? High-purity needled ceramic fiber blanket is a binder-free, resilient mat available in standard, high-purity and high-alumina grades, making it the default choice for furnace backup lining, expansion joints and module feedstock. Key Technical Specifications Property | Value | Maximum service temperature | classification 1260°C (HP 1350°C, HA 1430°C); service up to 1100–1250°C | Density | 64–160 kg/m³ (up to 300 for dense grades) | Thermal conductivity | ≤0.153 W/(m·K) at 500°C mean | Standard thickness | 6–50 mm | Standard dimensions | 610 / 1220 mm wide × 7320 / 7620 mm long | Fire classification | Non-combustible (ceramic fibre, asbestos-free) | Composition | high-purity alumino-silicate (Al₂O₃ + SiO₂) blown fibre, no organic binder | Standards | ASTM C892, ASTM C1086, ISO 10635, EN 10964 | Properties & Advantages - Binder-free, needled for high tensile strength - Low thermal conductivity and heat capacity - Excellent thermal-shock and chemical resistance - Resilient, reversible compression - Available across temperature grades Typical Applications - Backup lining of industrial furnaces - Expansion-joint packing and seals - High-temperature pipe wrapping - Feedstock for ceramic fiber modules Installation & Handling Lay parallel to the hot face and compress slightly at joints; stagger seams between layers. For module production, fold or stack to the required module density. Standards & Compliance Manufactured to ASTM C892, ASTM C1086, ISO 10635, EN 10964 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a high-purity ceramic fiber blanket manufacturer and supplier serving more than 60 countries since 1982. Every high-purity ceramic fiber blanket is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives ceramic fibre blanket insulation — Lightweight and easy to cut on site, it lines boiler combustion chambers, kiln bodies and high-temperature furnace shells without adding meaningful structural load. ceramic fiber tape for pipes — Flexible enough to follow small diameters and irregular fittings without lifting, making it practical for valves and flanges as well as straight runs. rockwool insulation board — Rigid basalt stone wool slabs, Class A1 non-combustible, water repellent and sound absorbing, with the compressive strength exterior wall systems require. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Lower shot content - Improved tensile strength - Consistent density - Enhanced thermal performance - Better handling - Reduced dust generation Applications: - High-performance furnace linings - Critical petrochemical equipment - Aerospace thermal protection - Precision heating equipment Specifications: - Density: 96/128/160 kg/m³ - Thickness: 10-50mm - Temperature: Up to 1260℃ - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100°C to 1430°C, depending on the grade. Standard (ST) and High-Purity (HP) grades are rated for 1260°C, while High-Alumina (HA) handles 1360°C and Zirconia (HZ) reaches 1430°C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al₂O₃) content and temperature rating. COM (1100°C) is the economy grade. ST (1260°C) is the standard industrial grade. HP (1260°C) offers higher purity with lower shot content. HA (1360°C) has higher alumina for superior thermal stability. HZ (1430°C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. ### Ceramic Fiber Rope URL: https://www.rosetexwool.net/products/ceramic-fiber-rope/ Category: Ceramic Fiber Summary: Twisted ceramic fiber rope for high-temperature sealing, gasketing, and expansion joint packing up to 1260℃. Made from high-quality ceramic fiber yarn twisted into strong, flexible rope with various reinforcement options including fiberglass or stainless steel wire. What Is Ceramic Fiber Rope? Ceramic fiber rope is a twisted or braided cord of ceramic-fibre yarn (with optional fibreglass or stainless-steel-wire reinforcement) used for sealing, gasketing and expansion-joint packing up to refractory temperatures. Key Technical Specifications Property | Value | Maximum service temperature | classification 1260°C; service up to 1100°C | Density | ≈500 kg/m³ (as rope) | Thermal conductivity | 0.10–0.18 W/(m·K) (as packed cord) | Standard thickness | diameter 6–50 mm | Standard dimensions | coils 5–25 m typical | Fire classification | Non-combustible (ceramic fibre, asbestos-free) | Composition | high-purity alumino-silicate (Al₂O₃ + SiO₂) blown fibre, no organic binder | Standards | ASTM C892, ASTM C1086, ISO 10635, EN 10964 | Properties & Advantages - Flexible, reusable high-temperature seal - Resists thermal cycling and flame impingement - Wire-reinforced grades add strength - Low heat storage, asbestos-free - Stable in oxidising atmospheres Typical Applications - Door and access-gasket packing - Expansion-joint and duct seals - Boiler and furnace sealing - Pump and valve stem packing Installation & Handling Pack into the joint and compress lightly; for moving or vibrating joints use the wire-reinforced grade and secure the ends to prevent unravelling. Standards & Compliance Manufactured to ASTM C892, ASTM C1086, ISO 10635, EN 10964 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a ceramic fiber rope manufacturer and supplier serving more than 60 countries since 1982. Every ceramic fiber rope is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives ceramic fiber bulk — Loose bulk fibre supplied for filling cavities and expansion joints, and as the raw material for vacuum-formed shapes and ceramic fibre textiles. ceramic fiber special shaped — Vacuum-formed shapes produced to your drawing, so burner blocks, ladle covers and complex furnace geometries arrive ready to fit. high density calcium silicate board — Ultra-high density board above 500 kg/m³ for applications where the insulation also has to carry mechanical load. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Low thermal conductivity - Good flexibility - Thermal shock resistance - Good chemical stability - Easy to install and replace Applications: - High-temperature door seals - Expansion joint packing - Flange gasketing - Pipe and cable wrapping Specifications: - Diameter: 6-50mm - Density: 500 ±15 kg/m³ - Temperature: Up to 1260℃ - Reinforcement: Fiberglass / Stainless steel wire - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100°C to 1430°C, depending on the grade. Standard (ST) and High-Purity (HP) grades are rated for 1260°C, while High-Alumina (HA) handles 1360°C and Zirconia (HZ) reaches 1430°C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al₂O₃) content and temperature rating. COM (1100°C) is the economy grade. ST (1260°C) is the standard industrial grade. HP (1260°C) offers higher purity with lower shot content. HA (1360°C) has higher alumina for superior thermal stability. HZ (1430°C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. ### Ceramic Fiber Special Shaped URL: https://www.rosetexwool.net/products/ceramic-fiber-special-shaped/ Category: Ceramic Fiber Summary: Custom-made ceramic fiber vacuum-formed shapes for specific industrial furnace and equipment geometries. Custom-manufactured through vacuum forming to meet specific dimensional and geometric requirements for unique insulation applications, burner blocks, and custom furnace components. What Is Ceramic Fiber Special Shaped Products? Vacuum-formed ceramic fiber special shapes are custom-moulded rigid parts made from ceramic fibre slurry, used where a precise geometry — burner blocks, peep sights, kiln furniture — must survive high heat without cracking. Key Technical Specifications Property | Value | Maximum service temperature | classification up to 1430°C; service up to 1250°C | Density | 300–600 kg/m³ (rigid) | Thermal conductivity | 0.10–0.20 W/(m·K) at 600–1000°C mean | Standard thickness | custom (typically 6–100 mm wall) | Standard dimensions | made to customer drawing; standard block 600×900 mm max | Fire classification | Non-combustible (ceramic fibre, asbestos-free) | Composition | high-purity alumino-silicate (Al₂O₃ + SiO₂) blown fibre, no organic binder | Standards | ASTM C892, ASTM C1086, ISO 10635, EN 10964 | Properties & Advantages - Complex, repeatable geometry from a drawing - Rigid yet lightweight and low heat storage - Excellent thermal-shock resistance - Machinable for final fit - Asbestos-free, stable in oxidising atmospheres Typical Applications - Burner blocks and sight ports - Kiln furniture and furnace fixtures - Custom liners and flow guides - Laboratory and R&D high-temperature parts Installation & Handling Position and seat the shaped part against the surrounding lining, bedding with ceramic-fibre paste where a gas-tight joint is required. Avoid impact during handling. Standards & Compliance Manufactured to ASTM C892, ASTM C1086, ISO 10635, EN 10964 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a ceramic fiber special shaped products manufacturer and supplier serving more than 60 countries since 1982. Every ceramic fiber special shaped products is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives mullite fiber board — Built for laboratory furnaces, specialty glass and advanced materials processing where standard refractory fibre would already be failing. ceramic fiber paper — Thin, uniform and flexible refractory paper for gaskets, expansion joints and sealing where every millimetre of thickness matters. calsil board — The reference choice for kiln and furnace linings where a hard block must resist mechanical load, thermal cycling and direct flame contact at the same time. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Custom shapes available - Excellent thermal insulation - Good mechanical strength - Low shrinkage - Lightweight, easy to install - Reduces installation time Applications: - Custom furnace linings - Burner blocks and quarls - Ladle and tundish covers - Special tube insulation - Petrochemical equipment Specifications: - Forming Method: Vacuum forming - Temperature: Up to 1430℃ - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100°C to 1430°C, depending on the grade. Standard (ST) and High-Purity (HP) grades are rated for 1260°C, while High-Alumina (HA) handles 1360°C and Zirconia (HZ) reaches 1430°C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al₂O₃) content and temperature rating. COM (1100°C) is the economy grade. ST (1260°C) is the standard industrial grade. HP (1260°C) offers higher purity with lower shot content. HA (1360°C) has higher alumina for superior thermal stability. HZ (1430°C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. ### Ceramic Fiber Tape URL: https://www.rosetexwool.net/products/ceramic-fiber-tape/ Category: Ceramic Fiber Summary: Heat resistant ceramic fiber insulation tape for pipe wrapping, cable protection, and high-temperature sealing. Woven textile from high-quality ceramic fiber yarn providing thermal insulation, fire resistance, and flexibility for wrapping pipes, cables, and irregular shapes. What Is Ceramic Fiber Tape? Ceramic fiber tape is a narrow woven flat tape made from ceramic-fibre yarn (often reinforced with fibreglass or stainless-steel wire), used for wrapping, gasketing and protective jacketing in high-temperature service. Key Technical Specifications Property | Value | Maximum service temperature | classification 1260°C; service up to 1100°C | Density | woven yarn basis; finished tape 2–6 mm thick | Thermal conductivity | 0.08–0.15 W/(m·K) (as wrapped layer) | Standard thickness | 2–6 mm | Standard dimensions | widths 10–100 mm; rolls 30 m typical | Fire classification | Non-combustible (ceramic fibre, asbestos-free) | Composition | high-purity alumino-silicate (Al₂O₃ + SiO₂) blown fibre, no organic binder | Standards | ASTM C892, ASTM C1086, ISO 10635, EN 10964 | Properties & Advantages - Flexible, narrow-section high-temp seal - Withstands repeated thermal cycling - Optional wire reinforcement for abrasion - Low thermal conductivity and heat storage - Asbestos-free, chemical-resistant Typical Applications - Hose, cable and conduit wrapping - Flange and manhole gasketing - Electrical and thermal barrier tapes - Expansion-joint edge protection Installation & Handling Wrap with a 50% overlap and secure the end with wire or high-temperature lacing. For live gaskets, compress lightly between flanges. Standards & Compliance Manufactured to ASTM C892, ASTM C1086, ISO 10635, EN 10964 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a ceramic fiber tape manufacturer and supplier serving more than 60 countries since 1982. Every ceramic fiber tape is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives custom ceramic fiber shapes — Lightweight and simple to install, custom forms remove the cutting waste and gap risk that come from trimming standard board to fit. loose ceramic fiber insulation — The practical answer for irregular voids, penetrations and furnace expansion joints where a pre-formed product would need extensive cutting and still leave gaps. rock wool acoustic panels — High-density stone wool panels tuned for a high noise reduction coefficient, giving thermal and acoustic performance from the same layer. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Flexible and easy to wrap - Up to 1260℃ resistance - Low thermal conductivity - Good chemical stability - Electric insulation - Asbestos-free Applications: - Pipe and valve insulation - Cable fire protection - Expansion joint gasketing - Protective wrapping for hoses - Removable insulation covers Specifications: - Thickness: 2/3/5mm - Width: 25-150mm - Temperature: Up to 1260℃ - Reinforcement: Fiberglass filament - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100°C to 1430°C, depending on the grade. Standard (ST) and High-Purity (HP) grades are rated for 1260°C, while High-Alumina (HA) handles 1360°C and Zirconia (HZ) reaches 1430°C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al₂O₃) content and temperature rating. COM (1100°C) is the economy grade. ST (1260°C) is the standard industrial grade. HP (1260°C) offers higher purity with lower shot content. HA (1360°C) has higher alumina for superior thermal stability. HZ (1430°C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. ### Glass Wool Blanket URL: https://www.rosetexwool.net/products/glass-wool-blanket/ Category: Glass Wool Summary: Centrifugal glass wool blanket for large-scale thermal and acoustic insulation with excellent shock absorption. Temperature: -120℃ ~ 400℃. Centrifugal glass wool felt designed for large-scale laying. Features thermal insulation and excellent shock absorption and sound absorption, especially for low and medium frequency vibration noise. Aluminum foil faced option available for enhanced heat radiation resistance. What Is Glass Wool Blanket? Glass wool blanket is a lightweight, flexible mat of fine glass fibres that delivers efficient thermal and acoustic insulation across a broad temperature span, from cryogenic service up to moderate process heat. Key Technical Specifications Property | Value | Maximum service temperature | −120°C to 400°C | Density | 10–48 kg/m³ (blanket/roll) | Thermal conductivity | 0.030–0.044 W/(m·K) at 25°C mean | Standard thickness | 25–200 mm | Standard dimensions | rolls/pads 600 / 1200 mm wide | Fire classification | A1 (non-combustible, EN 13501-1) | Composition | glass melted and spun into fine glass fibres with a thermosetting binder | Standards | ASTM C553, EN 13162 | Properties & Advantages - Very low weight and easy handling - Good thermal and acoustic performance - A1 non-combustible, dimensionally stable - Vapour-open and hydrophobic options - Cuts cleanly with a knife Typical Applications - HVAC duct and plant insulation - Building thermal and acoustic infill - Cold and tempered process piping - Transport and equipment insulation Installation & Handling Lay with butt joints tightly closed and secure with pins, bands or adhesive; compress slightly at seams. Jacket outdoor or buried installations to keep the mat dry. Standards & Compliance Manufactured to ASTM C553, EN 13162 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a glass wool blanket manufacturer and supplier serving more than 60 countries since 1982. Every glass wool blanket is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C553, EN 13162 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the glass wool insulation hub for the full range, or read the glass wool insulation buying guide for selection support. Related Glass Wool Products & Alternatives glass wool board — Semi-rigid board for building envelopes, HVAC casings and acoustic panels, light enough to handle in large sheets and easy to cut on site. microporous insulation board — Used as backup insulation in cement rotary kilns and industrial furnaces where every millimetre saved adds usable internal volume. ceramic fiber furnace modules — Anchored directly to the furnace shell, they shorten installation time and make liner replacement a local repair rather than a full rebuild. For the full glass wool range, temperature limits and density options, see our glass wool insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Excellent thermal insulation - Outstanding sound absorption (low/mid freq) - Excellent shock absorption - High water repellency (>98%) - Class A non-combustible - Wide temperature range (-120℃~400℃) - Aluminum foil facing option - Asbestos-free Applications: - High temperature workshops - Control rooms - Engine room walls and compartments - Flat roof lining - Large area pipe/equipment insulation - Vibration and noise control Specifications: - Density: 14-48 kg/m³ - Temperature: -120℃ ~ 400℃ - Length: 5-30m - Width: 0.4-1.2m - Thickness: 25-100mm - Thermal Conductivity: 0.036 W/m·K - Combustion: Class A Non-combustible - Water Repellency: >98% - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C518 — Intertek - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What is a centrifugal glass wool blanket? A: It is glass wool made by centrifugal spinning — molten glass is thrown into fine fibers, then collected, needled, and bonded into a flexible blanket. The process gives a light, resilient mat with low thermal conductivity and good acoustic absorption, rated here from −120°C to 400°C. Q: What temperature can a glass wool blanket withstand? A: Continuous service typically runs from −120°C to about 400°C, with some grades to 538°C short-term. The glass fiber itself only softens well above 600°C, but the organic binder chars between 300–500°C, so sustained high-temperature duty should use rock wool or ceramic fiber. Q: Is a glass wool blanket fireproof? A: Yes for fire propagation: glass wool is A1 non-combustible — it will not ignite or spread flame. It does not provide a fire barrier above its temperature limit, however; the binder degrades around 300–500°C, so for hot-face fire zones use rock wool or ceramic fiber. Q: What is glass wool blanket insulation used for? A: It is the standard lightweight insulation for HVAC ducts, building walls and roofs, acoustic panels and studio damping, and lagging on chilled or low-temperature pipes and equipment where both thermal and acoustic performance are needed. ### Glass Wool Board URL: https://www.rosetexwool.net/products/glass-wool-board/ Category: Glass Wool Summary: Rigid glass wool insulation board for building, HVAC, and industrial thermal and acoustic applications. Rigid glass wool board providing thermal and acoustic insulation in a convenient board format. Suitable for building envelope, HVAC systems, and industrial equipment requiring semi-rigid insulation with excellent thermal and sound absorption properties. Manufacturer & Supplier Rosetexwool is a glass wool board manufacturer and supplier serving more than 60 countries since 1982. Every glass wool board is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C553, EN 13162 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the glass wool insulation hub for the full range, or read the glass wool insulation buying guide for selection support. Related Glass Wool Products & Alternatives glass wool blanket — Centrifugal glass wool blanket covering −120 to 400 °C, with strong low and mid frequency sound absorption and water repellency above 98%. 1900C insulation board — Retains thermal shock resistance at temperatures that rule out conventional ceramic fibre grades. aerogel insulation blanket — The lowest thermal conductivity in the range, delivered as a flexible blanket for pipes and equipment where clearance is the binding constraint. For the full glass wool range, temperature limits and density options, see our glass wool insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Good thermal insulation - Sound absorption - Semi-rigid format - Easy to install - Lightweight - Asbestos-free Applications: - Building wall and roof insulation - HVAC system insulation - Industrial equipment casing - Acoustic treatment panels - Cold storage facilities Specifications: - Density: 24-100 kg/m³ - Form: Rigid board - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C518 — Intertek - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What makes microporous and aerogel insulation special? A: Microporous and aerogel insulation achieve the lowest thermal conductivity of any commercially available insulation material (as low as 0.020 W/m·K). They provide 3-5× better insulation than conventional materials at the same thickness, making them ideal for space-constrained applications where maximum thermal performance is critical. Q: Where is nano insulation board typically used? A: Nano and microporous insulation boards are commonly used in cement rotary kilns, steel ladles, continuous casting equipment, backup insulation behind refractory linings, battery pack thermal barriers, and aerospace applications. Their ultra-thin profile allows for significant space savings while maintaining superior thermal performance. Q: How durable are microporous insulation boards? A: Microporous boards require careful handling during installation due to their microporous structure. Once installed behind a protective facing or within an enclosed system, they provide decades of stable thermal performance with no degradation or settling. We provide encapsulation options for demanding industrial environments. ### Nano Aerogel Insulation Blanket URL: https://www.rosetexwool.net/products/nano-aerogel-insulation-blanket/ Category: Microporous & Aerogel Summary: Advanced nano aerogel insulation blanket with the lowest thermal conductivity for applications demanding minimal thickness. Nano aerogel insulation blanket delivers exceptional thermal performance with the lowest thermal conductivity among all insulation materials. Ideal for applications where space is at a premium and maximum thermal efficiency is required with minimal insulation thickness. What Is Nano Aerogel Insulation Blanket? Nano aerogel insulation blanket combines a silica-aerogel core with a needled glass-fibre carrier to deliver the lowest thermal conductivity of any flexible insulation, at a fraction of the thickness required by conventional materials. Key Technical Specifications Property | Value | Maximum service temperature | up to 650°C | Density | 160–200 kg/m³ | Thermal conductivity | 0.017–0.023 W/(m·K) at 25°C mean; ~0.032 W/(m·K) at 300°C | Standard thickness | 3–10 mm (common); multi-layer as needed | Standard dimensions | rolls up to 1500 mm wide | Fire classification | Non-combustible / A2-s1,d0 (EN 13501-1) | Composition | silica aerogel compounded with a needled glass-fibre carrier; hydrophobic yet vapour-permeable | Standards | ASTM C1728 (Type III, Grade 1A) | Properties & Advantages - Lowest thermal conductivity of flexible insulations - Hydrophobic yet vapour-permeable — strong CUI defence - Minimal thickness for tight clearances - Flexible, cut-to-fit, reusable - Non-combustible profile Typical Applications - CUI-prone steam and process lines - Space-constrained piping and vessels - LNG and cryogenic-to-hot transitions - Offshore and oil & gas insulation Installation & Handling Wrap with a 50% overlap and compress lightly at joints; for service above 400°C add a metallic foil barrier. Protect with jacketing and avoid saturating during washing. Standards & Compliance Manufactured to ASTM C1728 (Type III, Grade 1A) and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a nano aerogel insulation blanket manufacturer and supplier serving more than 60 countries since 1982. Every nano aerogel insulation blanket is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C1728 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the aerogel insulation hub for the full range. Related Nano & Aerogel Products & Alternatives nano board insulation — The choice when the design cannot give up thickness but the thermal target is not negotiable. high strength calcium silicate insulation — Asbestos-free and excellent in load bearing, it lets one layer do the insulating and the structural job at once. ceramic fiber fabric — Serving furnace curtains, expansion joint packing and welding protection blankets where the material has to move with the equipment instead of cracking. For the full nano and aerogel range, temperature limits and thickness data, see our aerogel insulation guide. For adjacent material options across temperature and application ranges, explore our ceramic fiber insulation hub. Features: - Lowest thermal conductivity - Ultra-thin insulation - Excellent thermal performance - Flexible construction - Space-saving - Nano-technology Applications: - Space-constrained pipe insulation - Process equipment with limited clearance - Subsea and offshore applications - Building envelope energy efficiency - Aerospace thermal management Specifications: - Material: Silica aerogel composite - Form: Flexible blanket - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C518 — Intertek - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What is an aerogel insulation blanket? A: A flexible insulation made by bonding silica aerogel — a nanoporous solid that is mostly air — onto a reinforcing fiber mat. It delivers the lowest thermal conductivity of any blanket (0.016–0.030 W/m·K) and is inherently hydrophobic. Q: How thin is aerogel insulation compared with traditional materials? A: For the same thermal resistance, roughly one-third to one-half the thickness of mineral wool: a 10–20 mm aerogel layer can replace 80–150 mm of conventional insulation in cryogenic service, and 3–25 mm covers most pipe duties from −200°C to 650°C. Q: What temperature can aerogel insulation withstand? A: Continuous service spans about −200°C to 650°C depending on grade, which covers LNG and liquid nitrogen lines at the cold end and hot process piping at the warm end. It is A1 non-combustible throughout its range. Q: Where is an aerogel insulation blanket used? A: Wherever space, weight, or corrosion-under-insulation risk is critical: pipe racks and offshore modules, valves and flanges, cryogenic and LNG lines, and retrofit projects where thicker traditional insulation will not fit. ### Nano Insulation Board URL: https://www.rosetexwool.net/products/nano-insulation-board/ Category: Microporous & Aerogel Summary: Nano-technology microporous insulation board with exceptional thermal performance and minimal thickness. Microporous nano insulation board utilizing advanced nano-scale technology to achieve exceptionally low thermal conductivity in a rigid board format. Combines space-saving thin profile with superior insulation performance for demanding industrial applications. What Is Nano Microporous Insulation Board? Nano microporous insulation board is a rigid, silica-based microporous panel that approaches the conductivity of still air, enabling very thin, high-performance linings where space or weight is at a premium. Key Technical Specifications Property | Value | Maximum service temperature | up to 1000°C | Density | 200–350 kg/m³ | Thermal conductivity | ≈0.020–0.024 W/(m·K) at 25°C mean; ~0.05 W/(m·K) at 800°C | Standard thickness | 3–50 mm | Standard dimensions | panels up to 1000×1200 mm and custom | Fire classification | Non-combustible / A2-s1,d0 (EN 13501-1) | Composition | silica aerogel compounded with a needled glass-fibre carrier; hydrophobic yet vapour-permeable | Standards | ASTM C1728 (Type III, Grade 1A) | Properties & Advantages - Near-still-air thermal conductivity - Very thin sections for the same performance - Rigid, easy to cut and laminate - Low heat storage, fast thermal response - Non-combustible microporous core Typical Applications - Kiln and furnace linings - Equipment where thickness is limited - Backing behind refractory hot face - High-value, space-constrained insulation Installation & Handling Cut with a fine-tooth blade, laminate behind the hot face and avoid compressing the core, which would raise conductivity. Seal edges where moisture exposure is possible. Standards & Compliance Manufactured to ASTM C1728 (Type III, Grade 1A) and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a nano microporous insulation board manufacturer and supplier serving more than 60 countries since 1982. Every nano microporous insulation board is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C1728 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the aerogel insulation hub for the full range. Related Nano & Aerogel Products & Alternatives silica aerogel blanket insulation — Worth the premium when space, weight or access rules out a thicker build-up — otherwise a cheaper material will do the same job. high temperature tape insulation — Chemically stable and low conductivity, it is the quick fix for cable fire protection and short sections of hot line. medium temperature insulation board — Lightweight, easy to work and stable across its rated range, which keeps material cost down on equipment that never approaches refractory temperatures. For the full nano and aerogel range, temperature limits and thickness data, see our aerogel insulation guide. For adjacent material options across temperature and application ranges, explore our ceramic fiber insulation hub. Features: - Exceptional thermal performance - Ultra-thin profile - Rigid board format - Space-saving solution - Long-term stability - Industrial-grade durability Applications: - Cement rotary kilns - Industrial furnace backup insulation - High-temperature equipment - Space-critical applications - Iron and steel processing Specifications: - Material: Nanoporous silica - Form: Rigid board - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C518 — Intertek - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What makes microporous and aerogel insulation special? A: Microporous and aerogel insulation achieve the lowest thermal conductivity of any commercially available insulation material (as low as 0.020 W/m·K). They provide 3-5× better insulation than conventional materials at the same thickness, making them ideal for space-constrained applications where maximum thermal performance is critical. Q: Where is nano insulation board typically used? A: Nano and microporous insulation boards are commonly used in cement rotary kilns, steel ladles, continuous casting equipment, backup insulation behind refractory linings, battery pack thermal barriers, and aerospace applications. Their ultra-thin profile allows for significant space savings while maintaining superior thermal performance. Q: How durable are microporous insulation boards? A: Microporous boards require careful handling during installation due to their microporous structure. Once installed behind a protective facing or within an enclosed system, they provide decades of stable thermal performance with no degradation or settling. We provide encapsulation options for demanding industrial environments. ### Polycrystalline Mullite Fiberboard URL: https://www.rosetexwool.net/products/polycrystalline-mullite-fiberboard/ Category: Ceramic Fiber Summary: Ultra-high temperature polycrystalline mullite fiberboard and blanket for applications up to 1900℃. Highest temperature grade ceramic fiber family using advanced polycrystalline mullite (3Al₂O₃·2SiO₂) fibers delivering exceptional thermal stability from 1600℃ to 1900℃. What Is Polycrystalline Mullite Fiber Board? Polycrystalline mullite fiber board is a rigid, ultra-high-temperature insulation made from high-alumina polycrystalline fibre, for service beyond the limit of standard ceramic fibre — furnaces, kilns and reactors above 1400°C. Key Technical Specifications Property | Value | Maximum service temperature | classification up to 1800°C; maximum service up to 1500–1650°C | Density | 300–600 kg/m³ | Thermal conductivity | 0.15–0.35 W/(m·K) at 800–1200°C mean | Standard thickness | 6–100 mm | Standard dimensions | 600×900 mm, 1000×1200 mm and custom | Fire classification | Non-combustible (refractory ceramic fibre) | Composition | polycrystalline mullite (Al₂O₃ 72–83%, Al₂O₃+SiO₂ ≥ 99%) fibre, inorganic binder | Standards | ASTM C1786 (mullite fiber products) | Properties & Advantages - Highest temperature grade in the fiber family - Minimal shrinkage and deformation at 1500°C+ - Rigid, machinable and self-supporting - Excellent chemical and erosion resistance - Asbestos-free, very low impurity Typical Applications - Ultra-high-temperature furnaces (>1400°C) - Ceramic kilns, tunnel and roller kilns - Petrochemical cracking furnaces - Laboratory and test furnaces Installation & Handling Cut with a carbide blade, seat against the lining and support vertically. Use ceramic anchors rated for the service temperature; avoid mechanical shock on thin sections. Standards & Compliance Manufactured to ASTM C1786 (mullite fiber products) and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a polycrystalline mullite fiberboard manufacturer and supplier serving more than 60 countries since 1982. Every polycrystalline mullite fiberboard is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C892, ASTM C1086, EN 10964 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the ceramic fiber insulation hub for the full range, or read the ceramic fiber insulation buying guide for selection support. Related Ceramic Fiber Products & Alternatives ceramic fiber blanket — Needled refractory blanket rated 1100–1430 °C with very low thermal conductivity and the thermal shock resistance that rapid furnace cycling demands. ceramic fiber board insulation — Used for kiln linings, heat treatment equipment and cryogenic tank insulation where a self-supporting panel beats a flexible blanket. composite silicate plate — A soft, flexible plate made from rare earth cotton for medium-temperature work to 600 °C, asbestos-free and easy to cut. For the full ceramic fiber range, temperature grades and density options, see our ceramic fiber insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Ultra-high temperature to 1900℃ - Exceptional thermal stability - Very low thermal conductivity - Excellent thermal shock resistance - Low shrinkage - Superior chemical resistance Applications: - Ultra-high-temperature lab furnaces - Specialty glass production - Advanced materials processing - Semiconductor manufacturing - Aerospace thermal protection Specifications: - Class. Temp.: 1600/1700/1800/1900℃ - Material: Polycrystalline Mullite - Form: Fiberboard and Blanket Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - CE Marking — TÜV Rheinland — CE-REF-2025-042 - REACH Compliant — ECHA - RoHS Compliant — SGS FAQ: Q: What temperature can ceramic fiber insulation withstand? A: Ceramic fiber insulation withstands temperatures from 1100°C to 1430°C, depending on the grade. Standard (ST) and High-Purity (HP) grades are rated for 1260°C, while High-Alumina (HA) handles 1360°C and Zirconia (HZ) reaches 1430°C. Always match the grade to your specific operating temperature. Q: What are the differences between COM, ST, HP, HA, and HZ grades? A: The grades differ mainly in alumina (Al₂O₃) content and temperature rating. COM (1100°C) is the economy grade. ST (1260°C) is the standard industrial grade. HP (1260°C) offers higher purity with lower shot content. HA (1360°C) has higher alumina for superior thermal stability. HZ (1430°C) contains zirconia for the highest temperature resistance. Q: Is ceramic fiber insulation safe? A: Yes. Our ceramic fiber products are 100% asbestos-free and manufactured to international safety standards. They are classified as non-carcinogenic under EU Directive 97/69/EC. We recommend standard PPE (gloves, dust mask) during handling, as with any fibrous insulation material. Q: How is ceramic fiber blanket installed? A: Ceramic fiber blanket can be cut to size with a utility knife and secured using high-temperature anchors, pins, or stud welding. For furnace linings, a layered installation is recommended. For pipe insulation, wrap and secure with stainless steel bands. Full installation guidance and technical support are provided with every order. Q: What are the typical applications for ceramic fiber products? A: Ceramic fiber is widely used in industrial furnaces, kilns, boilers, petrochemical heaters, power generation equipment, incinerators, and building fire protection systems. It is ideal for backup insulation, expansion joints, door seals, and high-temperature gaskets. ### rock Wool Acoustic Panels URL: https://www.rosetexwool.net/products/rock-wool-acoustic-panels/ Category: Rock Wool Summary: High-density rock wool acoustic panels for superior sound absorption and thermal insulation in buildings. Specially designed for high-performance sound absorption. Deliver excellent noise reduction coefficients while maintaining outstanding fire resistance and thermal insulation for auditoriums, studios, and industrial noise control. What Is Rock Wool Acoustic Panels? Rock wool acoustic panels use the open, porous fibre structure of stone wool to dissipate sound energy, delivering high noise-reduction alongside A1 fire safety for interiors, plant rooms and acoustic enclosures. Key Technical Specifications Property | Value | Maximum service temperature | up to 650°C (continuous) | Density | 40–100 kg/m³ (acoustic grade) | Thermal conductivity | 0.034–0.040 W/(m·K) at 25°C mean | Standard thickness | 25–100 mm | Standard dimensions | 600×1200 mm / 1000×1200 mm boards | Fire classification | A1 (non-combustible, EN 13501-1 / Euroclass A1) | Composition | basaltic rock melted above 1500°C and spun into mineral fibres; organic binder 2–5% by weight | Standards | EN 13162, ASTM C612 (Type IV, up to 650°C) | Properties & Advantages - High sound absorption across speech and machinery bands - A1 non-combustible — safe behind flammable finishes - Dimensionally stable and sag-resistant - Vapour-open and hydrophobic - Easy to cut, wrap and laminate to facings Typical Applications - Recording studios, auditoria and theatres - Open-plan office and partition absorption - HVAC plant rooms and machinery enclosures - Acoustic lining of casings and cabinets Installation & Handling Fix to a rigid substrate or frame with adhesive, mechanical clips or a fabric-wrap system. Avoid compressing the panel, which reduces both acoustic and thermal performance. Standards & Compliance Manufactured to EN 13162, ASTM C612 (Type IV, up to 650°C) and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a rock wool acoustic panels manufacturer and supplier serving more than 60 countries since 1982. Every rock wool acoustic panels is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against EN 13162, ASTM C612 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the Rock Wool insulation hub for the full range, or read the rock wool insulation selection guide for selection support. Related Rockwool Products & Alternatives rock wool blanket — The practical format for large pipes, tanks, vessels and ductwork where rigid pre-formed sections would be slow to fit and leave joints. rockwool strips insulation — Easy to handle in tight spaces and useful for filling stud cavities and frame gaps without wasteful cutting. high temperature rope seal — Easy to install and replace, which keeps routine maintenance on furnaces and hot gas ducts short and predictable. For the full stone wool range, temperature limits and density options, see our rockwool insulation guide. For adjacent material options across temperature and application ranges, explore our ceramic fiber insulation hub. Features: - Superior sound absorption (high NRC) - Class A non-combustible - Dual thermal and acoustic insulation - Dimensional stability - Easy to install - Moisture and mold resistant Applications: - Auditorium and theater acoustics - Recording studio treatment - Industrial noise control - Building partition insulation - HVAC noise attenuation Specifications: - Density: 60-150 kg/m³ - Thickness: 25-150mm - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C612 — Intertek - Euroclass A1 — TÜV Rheinland — CE-REF-2025-043 - REACH Compliant — ECHA FAQ: Q: What temperature can rock wool insulation withstand? A: Rock wool insulation can withstand temperatures up to 650 °C for standard grades. It is classified as a non-combustible material (Euroclass A1, ASTM E84 Class A), making it ideal for structural fire protection, industrial pipe insulation, and building envelope applications. Q: Does rock wool absorb water? A: No. Our rock wool products feature hydrophobic treatment with water repellency exceeding 98%. Unlike some insulation materials, rock wool maintains its thermal performance even in high-humidity environments. This makes it particularly suitable for outdoor pipework and marine applications. Q: Is rock wool environmentally friendly? A: Yes. Rock wool is manufactured from volcanic basalt rock — an abundant natural resource. It contains up to 75% recycled content, is fully recyclable at end of life, and contributes to building energy efficiency by reducing heat loss. It is RoHS and REACH compliant. Q: What density of rock wool insulation should I use? A: The optimal density depends on your application: 60–80 kg/m³ for general thermal insulation of tanks and vessels, 80–120 kg/m³ for pipe insulation and HVAC ductwork, 100–150 kg/m³ for load-bearing or structural applications, and 150+ kg/m³ for high-compression industrial flooring and sandwich panels. ### Rockwool Insulation Blanket (Rock Wool Blanket) URL: https://www.rosetexwool.net/products/rock-wool-blanket/ Category: Rock Wool Summary: Flexible rockwool insulation blanket (also rock wool blanket) for large area coverage, pipe and equipment thermal insulation. Rockwool Insulation Blanket for Industrial Applications Rockwool insulation blanket (also written rock wool blanket) is a flexible roll-form thermal and acoustic insulation product manufactured from high-quality basalt fibers. It is designed for large-area coverage on pipes, vessels, ducts, and equipment where rigid pre-formed sections are impractical. As a versatile rock wool blanket, it conforms to curved and irregular surfaces while delivering uniform thermal performance. Our rockwool insulation blanket is engineered for continuous service up to 650 °C. With thermal conductivity of 0.034-0.040 W/(m.K) at 50C, Class A1 non-combustibility, and hydrophobic water repellency exceeding 98%, it is the preferred rock wool blanket solution for industrial, commercial, and HVAC applications. Key Features of Rockwool Insulation Blanket - Flexible for curved surfaces - rolls easily wrap around pipes, elbows, and irregular equipment - Excellent thermal insulation - low thermal conductivity minimizes heat loss across operating range - Good sound absorption - reduces noise transmission in mechanical rooms and plant areas - Class A1 non-combustible - Euroclass A1 and ASTM E84 Class A fire rating, will not contribute to fire spread - Water repellent - hydrophobic treatment maintains thermal performance in humid environments - Asbestos-free - 100% non-asbestos, formaldehyde-free binder system Rock Wool Blanket vs Rockwool Insulation Blanket Both terms refer to the same basalt-fiber roll product. "Rock wool blanket" is the traditional two-word spelling, while "rockwool insulation blanket" emphasizes the insulation function and the single-word brand-style spelling. Either way, the material delivers identical performance: flexible, fire-resistant, and thermally efficient. Typical Applications - Large diameter pipes - insulation of Process piping, steam lines, and chilled water mains - Industrial tanks and vessels - thermal and condensation control for storage and process equipment - HVAC duct insulation - acoustic and thermal treatment of air handling systems - Building envelope - roof, wall cavity, and facade insulation in commercial construction - Power plant equipment - boiler, turbine, and auxiliary system insulation - Marine and offshore - engine room and exhaust insulation Material Comparison Property | Rockwool Blanket | Glass Wool Blanket | Ceramic Fiber Blanket | Calcium Silicate | Max Temperature | 650 °C | 450C | 1430C | 1050C | Thermal Conductivity | 0.034-0.040 | 0.030-0.036 | 0.080-0.120 | 0.045-0.055 | Fire Rating | Class A1 | Class A1 | Class A1 | Class A1 | Flexibility | High | High | Medium | Rigid | Water Repellency | 98%+ | No | No | No | Density | 60-150 kg/m3 | 10-96 | 96-160 | 170-240 | Technical Specifications Our rockwool insulation blanket is available in densities from 60 to 150 kg/m3, thicknesses from 25mm to 100mm, and roll widths from 600mm to 1200mm. Standard facings include plain, aluminum foil, wire mesh, and glass fiber mesh for mechanical protection and vapor barrier performance. All products are manufactured under ISO 9001 quality management, with third-party certifications from SGS, Intertek, and TUV Rheinland. Products comply with ASTM C612, Euroclass A1, and REACH requirements. Quality Assurance - ISO 9001 certified manufacturing (SGS #CN-QMS-2025-001) - ASTM C612 Type IIA-V compliant (Intertek tested) - Euroclass A1 fire classification (TUV Rheinland #CE-REF-2025-043) - REACH compliant (ECHA registered) - 100% non-asbestos, formaldehyde-free binder For project-specific technical data sheets, material safety data sheets, or custom roll dimensions, contact our engineering team for a tailored quote. Manufacturer & Supplier Rosetexwool is a rock wool blanket manufacturer and supplier serving more than 60 countries since 1982. Every rock wool blanket is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against EN 13162, ASTM C612 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the Rock Wool insulation hub for the full range, or read the rock wool insulation selection guide for selection support. Related Rockwool Products & Alternatives rock wool board — The standard slab format for external wall insulation, firestop walls, flat and metal roofs and curtain wall cavity filling. rock wool pipe sections — Built for steam mains, district heating and refinery process lines, with water repellency above 98% and Class A1 non-combustibility. glasswool board insulation — Combining thermal insulation with sound absorption, it suits wall and roof build-ups where two separate products would otherwise be specified. For the full stone wool range, temperature limits and density options, see our rockwool insulation guide. For adjacent material options across temperature and application ranges, explore our ceramic fiber insulation hub. Features: - Flexible for curved surfaces - Excellent thermal insulation - Good sound absorption - Class A non-combustible - Water repellent - Asbestos-free Applications: - Large diameter pipes - Industrial tanks and vessels - HVAC duct insulation - Building envelope - Power plant equipment - Rockwool insulation blanket for large pipes Specifications: - Density: 60-150 kg/m3 - Thickness: 25-100mm - Temperature: Up to 600C - Asbestos: 100% Non-Asbestos - Thermal Conductivity: 0.034-0.040 W/(m.K) @50C - Roll Width: 600-1200mm - Surface Treatment: Plain / Aluminum foil / Wire mesh / Glass mesh Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C612 — Intertek - Euroclass A1 — TÜV Rheinland — CE-REF-2025-043 - REACH Compliant — ECHA FAQ: Q: What temperature can rock wool insulation withstand? A: Rock wool insulation can withstand temperatures up to 650 °C for standard grades. It is classified as a non-combustible material (Euroclass A1, ASTM E84 Class A), making it ideal for structural fire protection, industrial pipe insulation, and building envelope applications. Q: Does rock wool absorb water? A: No. Our rock wool products feature hydrophobic treatment with water repellency exceeding 98%. Unlike some insulation materials, rock wool maintains its thermal performance even in high-humidity environments. This makes it particularly suitable for outdoor pipework and marine applications. Q: Is rock wool environmentally friendly? A: Yes. Rock wool is manufactured from volcanic basalt rock - an abundant natural resource. It contains up to 75% recycled content, is fully recyclable at end of life, and contributes to building energy efficiency by reducing heat loss. It is RoHS and REACH compliant. Q: What density of rock wool insulation should I use? A: The optimal density depends on your application: 60-80 kg/m3 for general thermal insulation of tanks and vessels, 80-120 kg/m3 for pipe insulation and HVAC ductwork, 100-150 kg/m3 for load-bearing or structural applications, and 150+ kg/m3 for high-compression industrial flooring and sandwich panels. Q: What is rockwool insulation blanket? A: Rockwool insulation blanket (also called rock wool blanket) is a flexible roll-form insulation product made from molten basalt rock spun into fibers. It is designed for wrapping pipes, vessels, ducts, and equipment where rigid pre-formed sections cannot fit. As a rockwool insulation blanket, it provides thermal insulation, fire protection, and sound absorption in one flexible layer. Standard grades withstand 600C, with high-temperature grades rated to 650 °C. It is available in densities from 60 to 150 kg/m3 with optional foil, wire mesh, or glass fiber mesh facing. Q: What is the difference between rock wool blanket and rockwool insulation blanket? A: There is no material difference - rock wool blanket and rockwool insulation blanket are two spellings for the same basalt-fiber roll insulation product. "Rock wool blanket" is the traditional two-word form, while "rockwool insulation blanket" uses the single-word brand-style spelling and highlights the insulation function. Both refer to the flexible, fire-resistant, thermally efficient roll product used for pipes, tanks, ducts, and building envelope insulation. Performance specifications (density 60-150 kg/m3, temperature up to 650 °C, Class A1 fire rating) are identical regardless of spelling. ### Rock Wool Blanket with Glass Fiber Mesh URL: https://www.rosetexwool.net/products/rock-wool-blanket-glass-mesh/ Category: Rock Wool Summary: Rock wool blanket reinforced with glass fiber mesh for improved surface durability and handling strength. rock wool blanket with glass fiber mesh facing providing improved surface durability, handling strength, and a smoother finish for industrial and building insulation applications where surface reinforcement is beneficial. What Is Rock Wool Blanket with Glass Fibre Mesh? This rock wool blanket carries a glass-fibre mesh on one or both faces, adding surface abuse-resistance and easier handling while keeping the thermal and fire performance of standard stone-wool mat. Key Technical Specifications Property | Value | Maximum service temperature | up to 650°C (continuous) | Density | 80–140 kg/m³ | Thermal conductivity | 0.036–0.042 W/(m·K) at 25°C mean | Standard thickness | 25–100 mm | Standard dimensions | rolls 600 / 1200 mm wide × up to 5000 mm long | Fire classification | A1 (non-combustible, EN 13501-1 / Euroclass A1) | Composition | basaltic rock melted above 1500°C and spun into mineral fibres; organic binder 2–5% by weight | Standards | EN 13162, ASTM C612 (Type IV, up to 650°C) | Properties & Advantages - Glass-mesh facing improves tear resistance and handling - Holds shape on vertical and curved surfaces - A1 non-combustible, low heat capacity - Resists mechanical abuse during service - Cuts cleanly and layers without bridging Typical Applications - Industrial equipment and vessel insulation - Offshore and marine systems - Ducts, stacks and flue gas lines - Abuse-exposed plant-room insulation Installation & Handling Position the mesh-faced side outwards, secure with bands, pins or mesh ties, and butt seams tightly. Protect outdoor installations with a suitable weather jacket. Standards & Compliance Manufactured to EN 13162, ASTM C612 (Type IV, up to 650°C) and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a rock wool blanket with glass fibre mesh manufacturer and supplier serving more than 60 countries since 1982. Every rock wool blanket with glass fibre mesh is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against EN 13162, ASTM C612 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the Rock Wool insulation hub for the full range, or read the rock wool insulation selection guide for selection support. Related Rockwool Products & Alternatives rockwool wired blanket — Class A1 non-combustible and suited to big flat or curved areas where the insulation has to stay put under its own weight. stone wool blanket insulation — Class A1 non-combustible and water repellent, it handles large-area coverage without the seams that create thermal bridges. ceramic fiber plus blanket — An upgraded blanket with lower shot content and improved tensile strength, aimed at linings where consistency matters more than price. For the full stone wool range, temperature limits and density options, see our rockwool insulation guide. For adjacent material options across temperature and application ranges, explore our ceramic fiber insulation hub. Features: - Glass fiber mesh reinforcement - Improved surface durability - Better handling strength - Smoother finish - Class A non-combustible - Asbestos-free Applications: - Building wall insulation - HVAC system insulation - Industrial equipment - Pipe and duct insulation Specifications: - Density: 60-150 kg/m³ - Facing: Glass fiber mesh - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C612 — Intertek - Euroclass A1 — TÜV Rheinland — CE-REF-2025-043 - REACH Compliant — ECHA FAQ: Q: What temperature can rock wool insulation withstand? A: Rock wool insulation can withstand temperatures up to 650 °C for standard grades. It is classified as a non-combustible material (Euroclass A1, ASTM E84 Class A), making it ideal for structural fire protection, industrial pipe insulation, and building envelope applications. Q: Does rock wool absorb water? A: No. Our rock wool products feature hydrophobic treatment with water repellency exceeding 98%. Unlike some insulation materials, rock wool maintains its thermal performance even in high-humidity environments. This makes it particularly suitable for outdoor pipework and marine applications. Q: Is rock wool environmentally friendly? A: Yes. Rock wool is manufactured from volcanic basalt rock — an abundant natural resource. It contains up to 75% recycled content, is fully recyclable at end of life, and contributes to building energy efficiency by reducing heat loss. It is RoHS and REACH compliant. Q: What density of rock wool insulation should I use? A: The optimal density depends on your application: 60–80 kg/m³ for general thermal insulation of tanks and vessels, 80–120 kg/m³ for pipe insulation and HVAC ductwork, 100–150 kg/m³ for load-bearing or structural applications, and 150+ kg/m³ for high-compression industrial flooring and sandwich panels. ### Rockwool Insulation Slabs — Rock Wool Board URL: https://www.rosetexwool.net/products/rock-wool-board/ Category: Rock Wool Summary: Basalt rockwool insulation slabs (also rock wool board) — Class A non-combustible rockwool material. Fire-safe, water-repellent, sound-absorbing. Rock Wool Board — Rigid Basalt Insulation for Fire, Thermal & Acoustic Performance Rock wool board (also written rockwool or called mineral wool board / basalt wool board) is a rigid, high-density rockwool material supplied as standard rockwool insulation slabs. In legacy trade literature it is sometimes referenced as fire wool for its non-combustible character. Manufactured from natural basalt melted above 1450°C and spun into mineral fibers, then cured with a thermosetting binder, the panels deliver fire-safe, low-smoke thermal and acoustic insulation for building envelopes, industrial equipment, and power infrastructure. Key Properties - Fire safety (A1 non-combustible): inorganic basalt fibers do not burn, melt, or release toxic smoke; oxygen index ≥50, smoke toxicity class t0, fire resistance limit ≥3 hours — the defining property that makes rockwool a fire wool-grade insulation material. - Thermal insulation: thermal conductivity 0.034–0.042 W/(m·K); stable long-term performance with no aging decay. - Acoustic performance: open-porous structure provides high sound absorption for facades, partitions and HVAC ducts. - Hydrophobic & durable: water repellency ≥98.5%, water absorption by mass ≤1%, resists humidity in outdoor and marine use. - Mechanical strength: compressive strength ≥40 kPa (≥80 kPa for high-density grades), tensile strength perpendicular to face ≥10 kPa. - Chemically stable & eco-friendly: free of asbestos, formaldehyde and CFC; low-chloride grade (Cl⁻ ≤10 mg/kg) protects austenitic stainless steel; 100% recyclable. Common Forms Standard rockwool insulation slabs are produced in thicknesses of 25–150 mm and densities from 60 to 200 kg/m³, supplied as rigid panels (slabs), boards, and sandwich-panel cores. Rockwool material in slab form is the most widely specified format for building envelopes, industrial equipment insulation, structural fire barriers in substations, energy-storage station compartmentation, and petrochemical facilities. Manufacturer & Supplier Rosetexwool is a rock wool board manufacturer and supplier serving more than 60 countries since 1982. Every rock wool board is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against EN 13162, ASTM C612 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the Rock Wool insulation hub for the full range, or read the rock wool insulation selection guide for selection support. Related Rockwool Products & Alternatives pipe insulation for steam pipes — Sized DN15 to DN300 for a tight fit, which removes the thin spots and heat losses that field-wrapped insulation tends to leave. wired rockwool blanket — Stone wool blanket stitched to galvanised wire mesh so it can be mechanically fixed to large tanks, boilers and ductwork. ceramic fiber bulk — Loose bulk fibre supplied for filling cavities and expansion joints, and as the raw material for vacuum-formed shapes and ceramic fibre textiles. For the full stone wool range, temperature limits and density options, see our rockwool insulation guide. For adjacent material options across temperature and application ranges, explore our ceramic fiber insulation hub. Features: - Low thermal conductivity - Class A non-combustible - Excellent sound absorption - Water resistant - High compressive strength - Durable - Corrosion-resistant - Asbestos-free Applications: - Building exterior wall insulation (ETICS/EIFS) - Fire barrier & firestop walls - Flat & metal roof insulation - Curtain wall cavity filling - Partition walls and ceilings - HVAC duct insulation - Petroleum/chemical boiler & furnace insulation - Power/metallurgy equipment insulation - Substation, cable tray & cable trench fire barrier - Energy storage station fire compartmentation - Rockwool insulation slab for storage tanks - Marine & offshore rockwool insulation slabs - Rockwool fire barrier for substations & cable trenches Specifications: - Density: 60-150 kg/m³ - Raw Material: Basalt - Thickness: 25-150mm - Thermal Conductivity: ≤ 0.044 W/(m·K) - Combustion: Class A Non-combustible - Asbestos: 100% Non-Asbestos - Max Service Temperature: 600–700℃ (short-term 1000℃+) - Compressive Strength: ≥40 kPa (≥80 kPa high-density) - Tensile Strength (perp. to face): ≥10 kPa - Water Repellency: ≥98.5% - Water Absorption (by mass): ≤1% - Chloride Content: ≤10 mg/kg (low-chloride grade) - Fire Resistance Limit: ≥3 hours - Sound Absorption: High NRC (open-porous) Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C612 — Intertek - Euroclass A1 — TÜV Rheinland — CE-REF-2025-043 - REACH Compliant — ECHA FAQ: Q: What temperature can rockwool insulation withstand? A: Rockwool insulation can withstand temperatures up to 650 °C for standard grades. It is classified as a non-combustible material (Euroclass A1, ASTM E84 Class A), making it ideal for structural fire protection, industrial pipe insulation, and building envelope applications. Q: Does rock wool absorb water? A: No. Our rock wool products feature hydrophobic treatment with water repellency exceeding 98%. Unlike some insulation materials, rock wool maintains its thermal performance even in high-humidity environments. This makes it particularly suitable for outdoor pipework and marine applications. Q: Is rockwool environmentally friendly? A: Yes. Rockwool is manufactured from volcanic basalt rock — an abundant natural resource. It contains up to 75% recycled content, is fully recyclable at end of life, and contributes to building energy efficiency by reducing heat loss. It is RoHS and REACH compliant. Q: What density of rockwool insulation should I use? A: The optimal density depends on your application: 60–80 kg/m³ for general thermal insulation of tanks and vessels, 80–120 kg/m³ for pipe insulation and HVAC ductwork, 100–150 kg/m³ for load-bearing or structural applications, and 150+ kg/m³ for high-compression industrial flooring and sandwich panels. Q: What is rockwool board used for in construction? A: In buildings it is used for external wall insulation systems (ETICS/EIFS), fire barrier and firestop walls, flat and metal roof insulation, curtain wall cavity filling, partition walls, suspended ceilings and HVAC duct insulation — combining A1 fire safety with thermal and acoustic performance. Q: Can rockwool board be installed as a fire barrier? A: Yes. With an A1 non-combustible rating and a fire resistance limit of 3 hours or more, rigid rockwool board is widely used as fire barrier and firestop walls, cable tray / cable trench fire separation, and energy storage station compartmentation to stop fire spread. Q: What are rockwool insulation slabs and where are they used? A: Rockwool insulation slabs are rigid, high-density panels manufactured from basalt fibers, typically supplied in thicknesses of 25–150 mm and densities from 60 to 200 kg/m³. They are widely used for external wall insulation (ETICS/EIFS), fire barrier walls, flat and metal roofs, curtain wall cavities, partition walls, HVAC ductwork, and structural fire protection in substations, energy storage stations, and petrochemical facilities. Q: Is rockwool a fire-safe insulation material? A: Yes. Rockwool achieves Euroclass A1 / ASTM E84 Class A non-combustible rating, the highest possible fire-safety classification for an insulation material. Sometimes referenced in legacy trade literature as fire wool, it will not burn, melt, or release toxic smoke, with a fire resistance limit of 3 hours or more — making rockwool material the specification of choice for structural fire barriers and life-safety insulation. ### Rockwool Pipe Insulation for Steam Pipes URL: https://www.rosetexwool.net/products/rock-wool-pipe/ Category: Rock Wool Summary: Pre-formed rockwool pipe insulation sections for steam pipes, HVAC and industrial piping. Rigid pipe insulation material rated for continuous service to 650 °C, Class A1 non-combustible. Rockwool Pipe Insulation for Steam Pipes Rockwool pipe insulation (also written rock wool pipe insulation) is the industry-standard insulation pipe solution for industrial process piping, district heating networks, and high-temperature steam lines. These pre-formed cylindrical sections are manufactured from high-quality basalt wool, engineered to provide uniform thermal performance and reliable fire protection across a wide temperature range. As a dedicated pipe insulation material, rockwool pipe sections deliver excellent thermal conductivity (0.034-0.040 W/(m.K) at 50C), Class A1 non-combustibility, and hydrophobic water repellency exceeding 98%. They are specifically designed as insulation for steam pipes in power plants, petrochemical facilities, and refinery process lines where operating temperatures reach 650 °C. Why Choose Rockwool Insulation for Pipes - Pre-formed for quick installation - factory-cut to standard pipe diameters (DN15-DN300), ensuring uniform coverage and tight fit - Excellent thermal performance - low thermal conductivity minimizes heat loss from steam lines and hot process piping - Class A1 non-combustible - Euroclass A1 and ASTM E84 Class A fire rating, will not contribute to fire spread - Water repellent - hydrophobic treatment with 98%+ water repellency maintains performance in humid environments - Durable long service life - 15-20 year service life with stable dimensional properties - Sound absorption - additional acoustic insulation benefit for mechanical room pipework Insulation for Steam Pipes Applications Rockwool pipe insulation is the preferred insulation for steam pipes in: - Power plant steam pipes - main steam, reheat steam, and extraction steam lines operating at 500-650 °C - Petrochemical process piping - hydrocarbon process lines, refinery heater tubes, and hot oil circuits - District heating pipelines - buried and above-ground distribution mains for urban heating networks - Industrial process pipe insulation - chemical plants, steel mills, and food processing facilities - HVAC and chilled water piping - condensation control and energy conservation - Marine and offshore pipework - engine room exhaust and hot service lines Pipe Insulation Material Comparison Property | Rockwool Pipe | Calcium Silicate | Fiberglass Pipe | Ceramic Fiber | Max Temperature | 650 °C | 1050C | 540C | 1430C | Thermal Conductivity | 0.034-0.040 | 0.045-0.055 | 0.030-0.036 | 0.080-0.120 | Fire Rating | Class A1 | Class A1 | Class A1 | Class A1 | Water Repellency | 98%+ | No | No | No | Density | 60-150 kg/m3 | 170-240 | 32-96 | 96-160 | Pipe Fit | Pre-formed | Pre-formed | Pre-formed | Wrap | Technical Specifications Our rockwool pipe insulation sections are available in densities from 60 to 150 kg/m3, thicknesses from 25mm to 200mm, and inner diameters covering DN15 (1/2") through DN300 (12"). Standard outer jacket options include aluminum foil facing and fiberglass cloth for mechanical protection and vapor barrier performance. All products are manufactured under ISO 9001 quality management, with third-party certifications from SGS, Intertek, and TUV Rheinland. Products comply with ASTM C612, Euroclass A1, and REACH requirements. Quality Assurance - ISO 9001 certified manufacturing (SGS #CN-QMS-2025-001) - ASTM C612 Type IIA-V compliant (Intertek tested) - Euroclass A1 fire classification (TUV Rheinland #CE-REF-2025-043) - REACH compliant (ECHA registered) - 100% non-asbestos, formaldehyde-free binder system For project-specific technical data sheets, material safety data sheets, or custom diameter requirements, contact our engineering team for a tailored quote. Manufacturer & Supplier Rosetexwool is a rock wool pipe insulation manufacturer and supplier serving more than 60 countries since 1982. Every rock wool pipe insulation is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against EN 13162, ASTM C612 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the Rock Wool insulation hub for the full range, or read the rock wool insulation selection guide for selection support. Related Rockwool Products & Alternatives rockwool insulation blanket — Flexible stone wool blanket for continuous service to 650 °C, conforming to curved and irregular surfaces while keeping thermal performance uniform. rockwool insulation strips — Class A1 non-combustible with good acoustic performance, so perimeter sealing also keeps the fire and sound rating intact. rigid glass wool insulation — Holds its shape in framing and duct applications while staying far lighter than mineral board of similar thickness. For the full stone wool range, temperature limits and density options, see our rockwool insulation guide. For adjacent material options across temperature and application ranges, explore our ceramic fiber insulation hub. Features: - Pre-formed for quick installation - Uniform insulation thickness - Excellent thermal performance - Class A non-combustible - Water repellent - Durable long service life Applications: - Industrial process pipe insulation - District heating pipelines - Petrochemical thermal management - Power plant steam pipes - Commercial building services - Insulation for steam pipes in power plants - Rockwool pipe insulation for petrochemical plants Specifications: - Density: 60-150 kg/m3 - Thickness: 25-200mm - Asbestos: 100% Non-Asbestos - Temperature Rating: Up to 650 °C - Thermal Conductivity: 0.034-0.040 W/(m.K) @50C - Pipe Diameter Range: DN15-DN300 (1/2-12 inch) - Surface Treatment: Aluminum foil / fiberglass cloth facing Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C612 — Intertek - Euroclass A1 — TÜV Rheinland — CE-REF-2025-043 - REACH Compliant — ECHA FAQ: Q: What temperature can rock wool insulation withstand? A: Rock wool insulation can withstand temperatures up to 650 °C for standard grades. It is classified as a non-combustible material (Euroclass A1, ASTM E84 Class A), making it ideal for structural fire protection, industrial pipe insulation, and building envelope applications. Q: Does rock wool absorb water? A: No. Our rock wool products feature hydrophobic treatment with water repellency exceeding 98%. Unlike some insulation materials, rock wool maintains its thermal performance even in high-humidity environments. This makes it particularly suitable for outdoor pipework and marine applications. Q: Is rock wool environmentally friendly? A: Yes. Rock wool is manufactured from volcanic basalt rock - an abundant natural resource. It contains up to 75% recycled content, is fully recyclable at end of life, and contributes to building energy efficiency by reducing heat loss. It is RoHS and REACH compliant. Q: What density of rock wool insulation should I use? A: The optimal density depends on your application: 60-80 kg/m3 for general thermal insulation of tanks and vessels, 80-120 kg/m3 for pipe insulation and HVAC ductwork, 100-150 kg/m3 for load-bearing or structural applications, and 150+ kg/m3 for high-compression industrial flooring and sandwich panels. Q: What is rockwool pipe insulation? A: Rockwool pipe insulation (also called rock wool pipe section) is a pre-formed cylindrical insulation product made from molten basalt rock spun into fibers. It is designed specifically for insulating pipes in industrial, HVAC, and steam applications. As a rigid pipe insulation material, it provides uniform thermal performance, fire protection, and sound absorption. Rockwool insulation for pipes is available in densities from 60 to 150 kg/m3 and inner diameters from DN15 to DN300. Q: Is rockwool good insulation for steam pipes? A: Yes. Rockwool is one of the best insulation materials for steam pipes because it withstands temperatures up to 650 °C, provides Class A1 fire protection, and maintains thermal performance even in humid environments. As insulation for steam pipes, rockwool pipe sections minimize heat loss, reduce energy waste, and protect personnel from burn hazards. Power plants, petrochemical refineries, and district heating systems commonly use rockwool pipe insulation for main steam lines operating at 500-650 °C. Q: What is the best pipe insulation material? A: The best pipe insulation material depends on your operating temperature and application. For steam pipes and high-temperature process lines (up to 650 °C), rockwool pipe insulation is the industry standard due to its fire rating, thermal performance, and water repellency. For temperatures up to 1050C, calcium silicate pipe insulation is preferred. For chilled water and HVAC piping below 200C, fiberglass pipe insulation is cost-effective. For extreme heat up to 1430C, ceramic fiber pipe insulation is used. Rockwool remains the most versatile pipe insulation material for general industrial applications. ### rock Wool Strips URL: https://www.rosetexwool.net/products/rock-wool-strips/ Category: Rock Wool Summary: Narrow rock wool insulation strips for thermal insulation in specific gap-filling and joint applications. Precisely cut narrow sections of rock wool board maintaining all thermal and fire performance characteristics while providing dimensional precision for targeted insulation applications. What Is Rock Wool Strips? Rock wool strips are precision-cut narrow sections of rock wool board that retain the full thermal, acoustic and fire performance of the parent board while offering tight dimensional control for targeted gap-filling, joint insulation and narrow-cavity work. Key Technical Specifications Property | Value | Maximum service temperature | up to 650°C (continuous) | Density | 80–160 kg/m³ | Thermal conductivity | 0.034–0.040 W/(m·K) at 25°C mean (rises to ~0.07–0.09 W/(m·K) at 300°C) | Standard thickness | 20–100 mm (strip width 20–200 mm) | Standard dimensions | cut from 600×1200 mm or 1000×1200 mm board | Fire classification | A1 (non-combustible, EN 13501-1 / Euroclass A1) | Composition | basaltic rock melted above 1500°C and spun into mineral fibres; organic binder 2–5% by weight | Standards | EN 13162, ASTM C612 (Type IV, up to 650°C) | Properties & Advantages - Stable thermal conductivity and A1 non-combustibility in a slender profile - Dimensional precision for clean joints and tight gaps - Vapour-open (μ ≈ 1) — lets the assembly dry - Hydrophobic treatment limits water uptake on site - Acoustic absorption in resonant or narrow cavities Typical Applications - Expansion-joint and curtain-wall gap filling - Pipe-support and hanger insulation - Narrow wall/stud cavities and door cores - Perimeter and junction detailing in façade systems Installation & Handling Cut to the required width with a sharp insulation knife and friction-fit or adhere into the gap. Butt joints tightly; stagger layers where multiple passes are specified. Standards & Compliance Manufactured to EN 13162, ASTM C612 (Type IV, up to 650°C) and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a rock wool strips manufacturer and supplier serving more than 60 countries since 1982. Every rock wool strips is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against EN 13162, ASTM C612 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the Rock Wool insulation hub for the full range, or read the rock wool insulation selection guide for selection support. Related Rockwool Products & Alternatives stone wool insulation board — High compressive strength means it takes render and mechanical fixings without crushing, unlike lighter blanket products. rockwool pipe insulation — Pre-formed stone wool pipe sections for continuous service to 650 °C, factory-cut to standard diameters so coverage stays uniform. glass wool board — Semi-rigid board for building envelopes, HVAC casings and acoustic panels, light enough to handle in large sheets and easy to cut on site. For the full stone wool range, temperature limits and density options, see our rockwool insulation guide. For adjacent material options across temperature and application ranges, explore our ceramic fiber insulation hub. Features: - Precise dimensional cutting - Easy to handle - Excellent thermal performance - Class A non-combustible - Good acoustic performance - Asbestos-free Applications: - Joint and gap insulation - Frame and stud cavity filling - Perimeter fire barriers - Custom insulation applications Specifications: - Density: 60-150 kg/m³ - Thickness: 25-150mm - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C612 — Intertek - Euroclass A1 — TÜV Rheinland — CE-REF-2025-043 - REACH Compliant — ECHA FAQ: Q: What temperature can rock wool insulation withstand? A: Rock wool insulation can withstand temperatures up to 650 °C for standard grades. It is classified as a non-combustible material (Euroclass A1, ASTM E84 Class A), making it ideal for structural fire protection, industrial pipe insulation, and building envelope applications. Q: Does rock wool absorb water? A: No. Our rock wool products feature hydrophobic treatment with water repellency exceeding 98%. Unlike some insulation materials, rock wool maintains its thermal performance even in high-humidity environments. This makes it particularly suitable for outdoor pipework and marine applications. Q: Is rock wool environmentally friendly? A: Yes. Rock wool is manufactured from volcanic basalt rock — an abundant natural resource. It contains up to 75% recycled content, is fully recyclable at end of life, and contributes to building energy efficiency by reducing heat loss. It is RoHS and REACH compliant. Q: What density of rock wool insulation should I use? A: The optimal density depends on your application: 60–80 kg/m³ for general thermal insulation of tanks and vessels, 80–120 kg/m³ for pipe insulation and HVAC ductwork, 100–150 kg/m³ for load-bearing or structural applications, and 150+ kg/m³ for high-compression industrial flooring and sandwich panels. ### rock wool Wired Insulation Blanket URL: https://www.rosetexwool.net/products/rock-wool-wired-insulation-blanket/ Category: Rock Wool Summary: Galvanized wire mesh reinforced rock wool blanket for mechanically fixed insulation on large equipment and tanks. Features galvanized wire mesh reinforcement sewn to rock wool blanket for mechanical strength and secure fastening to large surfaces, tanks, and vessels where mechanical fixing is required. What Is Rock Wool Wired Blanket? Rock wool wired blanket is a flexible rock wool mat faced with galvanised or stainless-steel wire mesh, giving it the mechanical retention needed for vertical surfaces, high-velocity ducts and equipment that sees vibration or airflow erosion. Key Technical Specifications Property | Value | Maximum service temperature | up to 650°C (continuous) | Density | 100–140 kg/m³ | Thermal conductivity | 0.036–0.042 W/(m·K) at 25°C mean | Standard thickness | 25–100 mm | Standard dimensions | rolls 600 / 1200 mm wide × up to 5000 mm long | Fire classification | A1 (non-combustible, EN 13501-1 / Euroclass A1) | Composition | basaltic rock melted above 1500°C and spun into mineral fibres; organic binder 2–5% by weight | Standards | EN 13162, ASTM C612 (Type IV, up to 650°C) | Properties & Advantages - Wire-mesh facing holds the blanket on vertical and overhead surfaces - Resists vibration, airflow erosion and self-weight sag - A1 non-combustible with low heat storage - Conforms to complex geometries and flanged shapes - Quick to install with tying wire or pins Typical Applications - Boiler and furnace casings - Duct, stack and flue insulation - Vessel and turbine outer insulation - Offshore and marine high-velocity systems Installation & Handling Wrap the blanket over the surface and secure with the integrated wire mesh using tying wire, bands or stud welding pins. Overlap joints by one mesh cell and weatherproof exposed outdoor runs with metal jacketing. Standards & Compliance Manufactured to EN 13162, ASTM C612 (Type IV, up to 650°C) and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a rock wool wired blanket manufacturer and supplier serving more than 60 countries since 1982. Every rock wool wired blanket is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against EN 13162, ASTM C612 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the Rock Wool insulation hub for the full range, or read the rock wool insulation selection guide for selection support. Related Rockwool Products & Alternatives rock wool strips — Narrow stone wool strips cut to precise dimensions for joints, gaps and perimeter fire barriers where full boards will not fit. rockwool insulation board — Rigid basalt stone wool slabs, Class A1 non-combustible, water repellent and sound absorbing, with the compressive strength exterior wall systems require. ceramic fiber special shaped — Vacuum-formed shapes produced to your drawing, so burner blocks, ladle covers and complex furnace geometries arrive ready to fit. For the full stone wool range, temperature limits and density options, see our rockwool insulation guide. For adjacent material options across temperature and application ranges, explore our ceramic fiber insulation hub. Features: - Galvanized wire mesh reinforcement - Mechanical fastening capability - Excellent thermal insulation - Class A non-combustible - For large surface areas - Durable and long-lasting Applications: - Large storage tank insulation - Boiler and economizer insulation - Duct work insulation - Industrial oven casing - Shipbuilding and marine Specifications: - Density: 60-150 kg/m³ - Thickness: 25-150mm - Reinforcement: Galvanized wire mesh - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C612 — Intertek - Euroclass A1 — TÜV Rheinland — CE-REF-2025-043 - REACH Compliant — ECHA FAQ: Q: What temperature can rock wool insulation withstand? A: Rock wool insulation can withstand temperatures up to 650 °C for standard grades. It is classified as a non-combustible material (Euroclass A1, ASTM E84 Class A), making it ideal for structural fire protection, industrial pipe insulation, and building envelope applications. Q: Does rock wool absorb water? A: No. Our rock wool products feature hydrophobic treatment with water repellency exceeding 98%. Unlike some insulation materials, rock wool maintains its thermal performance even in high-humidity environments. This makes it particularly suitable for outdoor pipework and marine applications. Q: Is rock wool environmentally friendly? A: Yes. Rock wool is manufactured from volcanic basalt rock — an abundant natural resource. It contains up to 75% recycled content, is fully recyclable at end of life, and contributes to building energy efficiency by reducing heat loss. It is RoHS and REACH compliant. Q: What density of rock wool insulation should I use? A: The optimal density depends on your application: 60–80 kg/m³ for general thermal insulation of tanks and vessels, 80–120 kg/m³ for pipe insulation and HVAC ductwork, 100–150 kg/m³ for load-bearing or structural applications, and 150+ kg/m³ for high-compression industrial flooring and sandwich panels. ### Calcium Silicate Insulation Board URL: https://www.rosetexwool.net/products/calcium-silicate-insulation-board/ Category: Calcium Silicate Summary: High-strength calcium silicate insulation board (also known as calsil board) with excellent heat resistance and low thermal conductivity. Working temperature up to 1100C. A rigid silicate board ideal for industrial furnace and kiln lining. Calcium Silicate Insulation Board (Calsil Board) Calcium silicate insulation board — also known as calsil board or simply silicate board — is a rigid, high-strength industrial insulation product manufactured from silicic and calcic materials through pulping, shaping, steam curing, drying and post-processing. With a maximum working temperature of 1000/1050/1100C, calsil board is widely used in metallurgy, petroleum, chemical, mechanical, electrical, light industry and industrial kilns. Key Features - High temperature resistance: Rated for continuous use up to 1100C - High compressive strength: Up to 6 MPa, suitable for load-bearing insulation - Low thermal conductivity: Less than 0.056 W/m.K at mean temperature - Non-asbestos: 100% asbestos-free formula meeting ASTM C533 and EN 14306 - Easy to cut and machine: Rigid board form, no special tools required - Dimensional stability: Linear shrinkage less than 1.5% at rated temperature Applications of Calsil Board This versatile silicate board serves multiple high-temperature industrial applications: - Metallurgy: Furnace and kiln backup insulation, ladle and tundish covers - Petrochemical: Refinery equipment, pipe supports, and vessel insulation - Power generation: Turbine casings, boiler breechings, and ductwork - Ceramic industry: Kiln car decks and tunnel kiln insulation - Aluminium smelting: Electrolytic cell side insulation - Building: Heat insulation and soundproofing panels Calsil Board vs Other Insulation Materials Property | Calsil Board | Ceramic Fiber Board | Rock Wool Board | Max Temp | 1100C | 1430C | 650C | Compressive Strength | up to 6 MPa | up to 3 MPa | up to 0.5 MPa | Thermal Conductivity | 0.056 W/m.K | 0.085 W/m.K | 0.040 W/m.K | Form | Rigid board | Rigid board | Rigid board | Asbestos-free | Yes | Yes | Yes | Calsil board offers the highest compressive strength among common insulation boards, making it the preferred choice for load-bearing high-temperature applications. For even higher temperature requirements (above 1100C), ceramic fiber board is recommended. Quality and Standards Our calcium silicate insulation boards are manufactured under ISO 9001 quality management systems. Each batch is tested for density, compressive strength, thermal conductivity, and linear shrinkage. Products are exported to Japan, South Korea, Thailand, Indonesia, Malaysia, Pakistan, Vietnam, Singapore and other markets worldwide. Manufacturer & Supplier Rosetexwool is a calcium silicate insulation board manufacturer and supplier serving more than 60 countries since 1982. Every calcium silicate insulation board is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C533, EN 14306 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the calcium silicate insulation hub for the full range, or read the calcium silicate insulation buying guide for selection support. Related Calcium Silicate Products & Alternatives composite silicate plate — A soft, flexible plate made from rare earth cotton for medium-temperature work to 600 °C, asbestos-free and easy to cut. calcium silicate pipe insulation — Pre-formed pipe sections that keep insulation thickness uniform around the whole circumference, removing the thin spots hand-applied wraps tend to leave behind. wired rockwool blanket — Stone wool blanket stitched to galvanised wire mesh so it can be mechanically fixed to large tanks, boilers and ductwork. For the full calcium silicate range, temperature limits and strength data, see our calcium silicate insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Highest strength among hard insulation materials - No deformation at working temperature - Lower thermal conductivity than other hard blocks - 100% asbestos-free - High temperature resistance Applications: - Ceramic industry: high-temperature kiln insulation - Industrial furnaces: reducing heat loss - Building: heat insulation and soundproofing - Power plants: turbine and generator isolation - Petrochemical: equipment and pipeline isolation - Calsil board for load-bearing high-temperature industrial insulation Specifications: - Density: 170-500 kg/m3 - Raw Material: Quartz sand - Thickness: 25-150mm (10mm for high density) - Bending Strength: >=0.5 MPa - Compressive Strength: >=0.9 MPa - Thermal Conductivity: <=0.056 W/m.K - Linear Shrinkage: <=1.5% - Max Working Temp.: 650/1000/1100C - Size: 1000x500 / 600x300mm - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C533 — Intertek - CE Marking — TÜV Rheinland — CE-REF-2025-044 - REACH Compliant — ECHA FAQ: Q: What is the maximum temperature for calcium silicate insulation? A: Calcium silicate insulation boards can withstand continuous temperatures up to 1100C. They offer high compressive strength and excellent dimensional stability, making them ideal for high-temperature pipe supports, furnace backup insulation, and aluminium smelter applications. Q: How does calcium silicate compare to ceramic fiber? A: Calcium silicate offers significantly higher compressive strength (up to 6 MPa) than ceramic fiber blankets, making it the preferred choice for load-bearing insulation. It is supplied in rigid board form, easy to cut and machine. Ceramic fiber, however, offers higher temperature limits (up to 1430C) and lower thermal conductivity in blanket form. Q: Is calcium silicate asbestos-free? A: Absolutely. All our calcium silicate products are manufactured using an asbestos-free formula. They meet international health and safety standards including ASTM C533 and EN 14306, and are certified as non-hazardous material for transport and handling. Q: What is calsil board? A: Calsil board is a common industry abbreviation for calcium silicate board. It is the same product: a rigid, high-strength insulation board made from calcium silicate materials. Calsil board is widely used in metallurgy, petrochemical, and power generation industries for high-temperature insulation up to 1100C. Q: Is calsil board the same as calcium silicate board? A: Yes, calsil board and calcium silicate board are exactly the same product. 'Calsil' is simply the industry shorthand for 'calcium silicate.' Both terms refer to the same rigid insulation material manufactured from silicic and calcic compounds, rated for temperatures up to 1100C with compressive strength up to 6 MPa. Q: What is silicate board used for in industry? A: Silicate board, including calcium silicate board (calsil board), is used for high-temperature industrial insulation applications. Common uses include furnace and kiln backup insulation, pipe supports in petrochemical plants, turbine casings in power plants, kiln car decks in ceramic manufacturing, and electrolytic cell insulation in aluminium smelting. Its high compressive strength makes it ideal for load-bearing insulation scenarios. Q: What is calsil insulation board used for? A: Calsil board is the rigid, load-bearing layer in high-temperature linings: furnace and kiln backup walls, boiler casings and ducts, fire-rated walls and doors, petrochemical heater enclosures, and marine fire barriers. It is often the structural backup behind ceramic fiber or rock wool on the hot face. ### Calcium Silicate Pipe URL: https://www.rosetexwool.net/products/calcium-silicate-pipe/ Category: Calcium Silicate Summary: Pre-formed calcium silicate pipe insulation sections for industrial piping systems with working temperature up to 1100℃. Pre-formed calcium silicate pipe insulation providing uniform and efficient thermal insulation for industrial piping systems. Same high-temperature resistance and low thermal conductivity as the board form, optimized for pipe applications. What Is Calcium Silicate Pipe Insulation? Calcium silicate pipe insulation is supplied as pre-formed half-shells that snap around industrial piping, giving uniform, efficient thermal insulation with very low conductivity and a non-combustible A1 profile. Key Technical Specifications Property | Value | Maximum service temperature | up to 650°C (ASTM C533 Type I; high-temp grade to ~1000°C) | Density | 170–250 kg/m³ (Type I) | Thermal conductivity | ≤0.065 W/(m·K) at 100°C; ≤0.095 W/(m·K) at 400°C | Standard thickness | 25–100 mm | Standard dimensions | pre-formed half-shells, pipe OD 15–1000 mm+ | Fire classification | A1 (non-combustible, EN 13501-1) | Composition | xonotlite calcium silicate hydrate reinforced with inorganic fibre; 100% asbestos-free | Standards | ASTM C533, EN 14306 | Properties & Advantages - Very low thermal conductivity for a rigid material - A1 non-combustible, low chloride for stainless steel - Dimensional stability, low linear shrinkage - High compressive and flexural strength - Asbestos-free, easy to cut and fit Typical Applications - Steam and condensate distribution lines - Hot-oil and process piping - Power-plant and refinery pipework - District-heating and heat-transfer systems Installation & Handling Fit the half-shells around the pipe with joints staggered between layers and secure with stainless bands (316 grade for coastal/outdoor). Seal butt joints and apply aluminium jacketing on weather-exposed runs. Standards & Compliance Manufactured to ASTM C533, EN 14306 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a calcium silicate pipe insulation manufacturer and supplier serving more than 60 countries since 1982. Every calcium silicate pipe insulation is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C533, EN 14306 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the calcium silicate insulation hub for the full range, or read the calcium silicate insulation buying guide for selection support. Related Calcium Silicate Products & Alternatives calcium silicate insulation board — Rigid calsil board carrying the highest compressive strength of any hard insulation block, holding its shape without deformation at working temperature while staying fully asbestos-free. high density calcium silicate board — Ultra-high density board above 500 kg/m³ for applications where the insulation also has to carry mechanical load. nano insulation board — Microporous board with exceptional thermal performance in an ultra-thin rigid profile, stable over long service at temperature. For the full calcium silicate range, temperature limits and strength data, see our calcium silicate insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Pre-formed for pipes - Excellent thermal insulation - High temperature resistance - Uniform insulation thickness - Easy installation - Asbestos-free Applications: - Industrial steam pipe insulation - High-temperature process piping - Petrochemical pipe systems - Power plant piping - District heating networks Specifications: - Density: 170-500 kg/m³ - Raw Material: Quartz sand - Thickness: 25-100mm - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C533 — Intertek - CE Marking — TÜV Rheinland — CE-REF-2025-044 - REACH Compliant — ECHA FAQ: Q: What is the maximum temperature for calcium silicate insulation? A: Calcium silicate insulation boards can withstand continuous temperatures up to 1100°C. They offer high compressive strength and excellent dimensional stability, making them ideal for high-temperature pipe supports, furnace backup insulation, and aluminium smelter applications. Q: How does calcium silicate compare to ceramic fiber? A: Calcium silicate offers significantly higher compressive strength (up to 6 MPa) than ceramic fiber blankets, making it the preferred choice for load-bearing insulation. It is supplied in rigid board form, easy to cut and machine. Ceramic fiber, however, offers higher temperature limits (up to 1430°C) and lower thermal conductivity in blanket form. Q: Is calcium silicate asbestos-free? A: Absolutely. All our calcium silicate products are manufactured using an asbestos-free formula. They meet international health and safety standards including ASTM C533 and EN 14306, and are certified as non-hazardous material for transport and handling. ### Composite Silicate Plate URL: https://www.rosetexwool.net/products/composite-silicate-plate/ Category: Calcium Silicate Summary: Flexible composite silicate insulation plate from rare earth cotton for medium-temperature applications up to 600℃. Soft insulation plate made from rare earth cotton (magnesium silicate) offering flexibility and good thermal insulation at medium temperatures. Easy to install on curved and irregular surfaces. What Is Composite Silicate Insulation Plate? Composite silicate plate is a rigid, lightweight insulation board combining a calcium-silicate matrix with reinforcing fibres, giving low conductivity and easy fabrication for equipment and building envelopes. Key Technical Specifications Property | Value | Maximum service temperature | up to 650–1000°C (grade dependent) | Density | 200–400 kg/m³ | Thermal conductivity | ≤0.065 W/(m·K) at 100°C; ≤0.10 W/(m·K) at 400°C | Standard thickness | 25–100 mm | Standard dimensions | 600×900 mm, 1000×1200 mm and custom | Fire classification | A1 (non-combustible, EN 13501-1) | Composition | xonotlite calcium silicate hydrate reinforced with inorganic fibre; 100% asbestos-free | Standards | ASTM C533, EN 14306 | Properties & Advantages - Low conductivity with light weight - A1 non-combustible, asbestos-free - Easy to cut, drill and shape on site - Good dimensional stability - Clean, low-dust handling Typical Applications - Wall and roof insulation panels - Equipment and vessel cladding - Pre-insulated and sandwich panels - General high-temperature backing Installation & Handling Cut and fit with conventional tools, fix with adhesive, mechanical fasteners or within a panel system, and protect exterior faces with a weather barrier where required. Standards & Compliance Manufactured to ASTM C533, EN 14306 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a composite silicate insulation plate manufacturer and supplier serving more than 60 countries since 1982. Every composite silicate insulation plate is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C533, EN 14306 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the calcium silicate insulation hub for the full range, or read the calcium silicate insulation buying guide for selection support. Related Calcium Silicate Products & Alternatives calcium silicate board insulation — Lower thermal conductivity than comparable hard blocks, which lets you cut lining thickness without giving up the temperature margin or the structural strength. calsil pipe insulation — Moulded to standard pipe diameters so two halves close tightly on site, cutting installation time on long runs compared with wrapped or field-fabricated solutions. refractory ceramic fiber blanket — Choose it when the lining has to survive repeated heating and cooling without spalling — low heat storage also shortens cycle time and cuts fuel per batch. For the full calcium silicate range, temperature limits and strength data, see our calcium silicate insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Soft and flexible - Good thermal insulation - Easy to install on curves - Medium temperature rated - Asbestos-free - Cost-effective Applications: - Curved equipment insulation - Irregular surface coverage - Medium-temperature kilns - Pipe and duct wrap Specifications: - Raw Material: Rare Earth Cotton (Magnesium Silicate) - Working Temp.: 600℃ - Size: 1000×500×50mm / 300×600×50/60mm - Softness: Soft Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C533 — Intertek - CE Marking — TÜV Rheinland — CE-REF-2025-044 - REACH Compliant — ECHA FAQ: Q: What is the maximum temperature for calcium silicate insulation? A: Calcium silicate insulation boards can withstand continuous temperatures up to 1100°C. They offer high compressive strength and excellent dimensional stability, making them ideal for high-temperature pipe supports, furnace backup insulation, and aluminium smelter applications. Q: How does calcium silicate compare to ceramic fiber? A: Calcium silicate offers significantly higher compressive strength (up to 6 MPa) than ceramic fiber blankets, making it the preferred choice for load-bearing insulation. It is supplied in rigid board form, easy to cut and machine. Ceramic fiber, however, offers higher temperature limits (up to 1430°C) and lower thermal conductivity in blanket form. Q: Is calcium silicate asbestos-free? A: Absolutely. All our calcium silicate products are manufactured using an asbestos-free formula. They meet international health and safety standards including ASTM C533 and EN 14306, and are certified as non-hazardous material for transport and handling. ### High Density Calcium Silicate Board URL: https://www.rosetexwool.net/products/high-density-calcium-silicate-board/ Category: Calcium Silicate Summary: Ultra-high density calcium silicate board (>500kg/m³) for applications requiring maximum mechanical strength. High density calcium silicate board with density exceeding 500 kg/m³ custom manufactured for applications where maximum mechanical strength and load-bearing capacity are required alongside thermal insulation performance. What Is High-Density Calcium Silicate Board? High-density calcium silicate board pairs the low conductivity and A1 fire rating of calcium silicate with greater mechanical strength, suited to load-bearing or abuse-exposed insulation where standard board would deform. Key Technical Specifications Property | Value | Maximum service temperature | up to 1000°C | Density | 250–500 kg/m³ | Thermal conductivity | ≤0.065 W/(m·K) at 100°C; ≤0.10 W/(m·K) at 400°C | Standard thickness | 25–100 mm | Standard dimensions | 600×900 mm, 1000×1200 mm and custom | Fire classification | A1 (non-combustible, EN 13501-1) | Composition | xonotlite calcium silicate hydrate reinforced with inorganic fibre; 100% asbestos-free | Standards | ASTM C533, EN 14306 | Properties & Advantages - Higher compressive and flexural strength than standard grade - A1 non-combustible, low chloride - Dimensional stability at temperature - Machinable and screw/bolt friendly - Asbestos-free, long service life Typical Applications - Structural and equipment insulation - Kiln-car tops and furnace liners - Load-bearing or walk-on insulation - Pipe supports and abuse-exposed panels Installation & Handling Cut with a carbide blade or saw, fix with studs, screws or refractory adhesive and support any overhang. Joint and jacket outdoor sections as for standard calcium silicate. Standards & Compliance Manufactured to ASTM C533, EN 14306 and controlled under a documented quality system. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Why Specify This Product Combines stable high-temperature performance with straightforward on-site fabrication. The material is asbestos-free, chemically stable in neutral and oxidising atmospheres, and supplied with full technical data sheets to support specification and inspection. Supplied by a manufacturer holding ISO 9001, CE and SGS certifications, exporting high-temperature insulation to 60+ countries since 1982. Manufacturer & Supplier Rosetexwool is a high-density calcium silicate board manufacturer and supplier serving more than 60 countries since 1982. Every high-density calcium silicate board is produced under a documented quality system certified to ISO 9001, CE and SGS, with batch-level traceability from raw material to finished product. What our manufacturing capability covers: - In-house melting, fibre-forming and finishing lines for consistent grade and density - Dimensional, density and thermal checks against ASTM C533, EN 14306 - Asbestos-free, low-impurity formulations verified by incoming and outgoing inspection - Standard and custom sizes, OEM/ODM grades, and cut-to-size supply for project quantities For quotations, lead times or technical data sheets, contact our team with your specification and target service temperature. Explore the calcium silicate insulation hub for the full range, or read the calcium silicate insulation buying guide for selection support. Related Calcium Silicate Products & Alternatives composite silicate insulation board — The economical answer for medium-temperature kilns, ducts and curved equipment where the surface geometry rules out flat board. calcium silicate insulation board — Rigid calsil board carrying the highest compressive strength of any hard insulation block, holding its shape without deformation at working temperature while staying fully asbestos-free. nano aerogel blanket — Reaches the thermal performance of far thicker conventional insulation in a fraction of the thickness, which is why it is used subsea and offshore. For the full calcium silicate range, temperature limits and strength data, see our calcium silicate insulation guide. For adjacent material options across temperature and application ranges, explore our rock wool insulation hub. Features: - Ultra-high density - Maximum mechanical strength - Excellent load bearing - Thermal insulation - Asbestos-free - Customizable Applications: - Load-bearing insulation applications - Heavy industrial equipment - High-pressure environments - Structural insulation Specifications: - Density: >500 kg/m³ - Raw Material: Quartz sand - Thickness: 25-100mm (10mm for high density) - Asbestos: 100% Non-Asbestos Certifications: - ISO 9001 — SGS — CN-QMS-2025-001 - ASTM C533 — Intertek - CE Marking — TÜV Rheinland — CE-REF-2025-044 - REACH Compliant — ECHA FAQ: Q: What is the maximum temperature for calcium silicate insulation? A: Calcium silicate insulation boards can withstand continuous temperatures up to 1100°C. They offer high compressive strength and excellent dimensional stability, making them ideal for high-temperature pipe supports, furnace backup insulation, and aluminium smelter applications. Q: How does calcium silicate compare to ceramic fiber? A: Calcium silicate offers significantly higher compressive strength (up to 6 MPa) than ceramic fiber blankets, making it the preferred choice for load-bearing insulation. It is supplied in rigid board form, easy to cut and machine. Ceramic fiber, however, offers higher temperature limits (up to 1430°C) and lower thermal conductivity in blanket form. Q: Is calcium silicate asbestos-free? A: Absolutely. All our calcium silicate products are manufactured using an asbestos-free formula. They meet international health and safety standards including ASTM C533 and EN 14306, and are certified as non-hazardous material for transport and handling. ## Applications ### Marine & Offshore URL: https://www.rosetexwool.net/applications/marine-offshore/ Moisture- and corrosion-resistant thermal and fire insulation for ships and offshore structures — deck fire barriers, engine-room piping, LPG tank fire layers and 100% asbestos-free bulkheads. Key benefits: - Fire & Partition Safety: 100% asbestos-free calcium silicate bulkheads and rock wool decks provide high fire ratings in confined marine spaces. - Corrosion Resistance: Salt-spray-resistant boards and jackets perform reliably in high-humidity offshore environments. - Operational Efficiency: Exhaust and machinery insulation cuts radiant heat, improving crew safety and reducing energy loss. - Long Service Life: Durable, moisture-stable materials extend maintenance intervals on vessels and platforms. FAQ: Q: Are your marine insulation products asbestos-free? A: Yes. Our calcium silicate bulkhead fillings are 100% asbestos-free and salt-spray resistant, with high fire ratings for ship partitions. Q: What material insulates ship exhausts? A: Ceramic fiber insulation jackets rated for continuous service up to 1430 °C for exhausts, boilers and propulsion piping. Q: Can you protect LPG tanks? A: Yes. Calcium silicate jackets provide fire and thermal protection for LPG storage tanks and high-temperature marine piping. Q: What fire rating do marine bulkheads and decks require? A: Most machinery and accommodation boundaries are specified to A-60 (60 minutes on the cellulosic curve) or, in oil, gas and offshore areas, H-60 or H-120 on the faster hydrocarbon curve. The insulation system must hold the unexposed-side temperature limits for the full rating. Q: Is rock wool A1 non-combustible and accepted for ships? A: Yes. Mineral wool that meets EN ISO 1182 and EN ISO 1716 is classed A1 non-combustible under EN 13501-1 and is accepted for marine fire divisions when supported by IMO FTP Code evidence. Our rock wool is hydrophobic and salt-resistant for the marine environment. ### Nuclear Power URL: https://www.rosetexwool.net/applications/nuclear-power/ Radiation- and high-temperature-resistant insulation for nuclear power — auxiliary piping, fire compartments, waste storage and valve seals using calcium silicate and ceramic fiber. Key benefits: - Radiation & Heat Resistance: Calcium silicate and ceramic fiber withstand high temperature and radiation in reactor auxiliary systems and valve seals. - Containment Safety: Fire-rated partitions, doors and bulkheads protect nuclear facilities and waste-storage containers. - Waste Storage Stability: Insulation on waste containers prevents temperature rise of radioactive material and maintains safety margins. - Long Service Life: Durable, stable materials reduce inspection and replacement frequency in nuclear plants. FAQ: Q: Which insulation suits reactor auxiliary piping? A: Calcium silicate and ceramic fiber rated for high temperature and radiation environments in auxiliary lines and reactor valve seals. Q: Can you insulate nuclear waste containers? A: Yes. Thermal insulation layers on storage containers help maintain stable temperatures and safety margins. Q: Do you provide nuclear-grade fire doors? A: We supply high-temperature insulation for nuclear plant fire doors and partition systems; final nuclear qualification is confirmed per project specifications. Q: What fire-safety rating does nuclear insulation need? A: Materials in containment and safety-related areas are specified A1 non-combustible (EN 13501-1) with the lowest smoke and no flaming droplets (s1,d0), and low-smoke, halogen-free behavior under ASTM E84 and ASTM E662. The priority is keeping escape routes and equipment clear during a fire. Q: Are your insulation materials low-smoke and halogen-free? A: Yes. Our mineral wool insulation used for nuclear applications is non-combustible and formulated to be low-smoke and halogen-free, which is the defining requirement for containment insulation so that a fire does not release corrosive or toxic halogens into the plant. ### Green Building & Retrofit URL: https://www.rosetexwool.net/applications/green-building/ Energy-efficient insulation and retrofit solutions — industrial furnace energy-saving coatings, steel-structure fire wrapping, fire-door cores and partition walls using ceramic fiber and calcium silicate. Key benefits: - Energy Efficiency: Insulating coatings and wraps on boilers and pipes cut heat loss and reduce utility bills. - Fire Protection: Calcium silicate cladding on steel structures and fire doors slows heating, preserving structural integrity. - Retrofit Friendly: Lightweight boards and coatings upgrade existing buildings with minimal added structural load. - Long Service Life: Durable, stable systems extend renovation payback and asset life. FAQ: Q: How do you improve industrial furnace efficiency? A: High-temperature insulating coatings (conductivity about 0.03 W/m·K, up to 1000°C) plus ceramic fiber linings reduce furnace shell heat loss. Q: Can you fire-protect steel structures? A: Yes. Calcium silicate cladding wraps steel columns and beams, slowing temperature rise and maintaining load capacity. Q: Are your products eco-friendly? A: We use asbestos-free calcium silicate and low-impact ceramic fiber aligned with green-building and sustainability goals. Q: Does insulation help earn LEED or BREEAM credits? A: Yes. Insulation contributes to Energy and Atmosphere credits through optimized thermal performance and to Materials and Resources credits through EPDs, recycled content and low-emitting documentation. A continuous, fire-safe envelope that breaks thermal bridging also supports additional innovation credits. Q: Are your insulation products non-combustible and low-emission? A: Our mineral wool and calcium silicate products are A1 non-combustible under EN 13501-1 and are formulated to be low-emitting and low-VOC, supporting indoor air-quality credits in LEED and BREEAM. ### Cryogenic Insulation URL: https://www.rosetexwool.net/applications/cryogenic-insulation/ Low-temperature insulation for cold chains and cryogenic systems — cold-storage walls, refrigerated transport, low-temperature labs and liquid-nitrogen piping using calcium silicate and glass wool. Key benefits: - Cold Retention: Low-temperature-stable boards and blankets maintain stable cold-chain and laboratory environments. - Moisture Resistance: Calcium silicate resists moisture and condensation at low temperatures, preventing degradation. - Energy Savings: Effective envelopes cut refrigeration loads and lower operating costs. - Long Service Life: Durable insulation reduces rework in cold storage and refrigerated transport. FAQ: Q: What insulation is used for cold storage walls? A: Calcium silicate exterior boards (low-temperature and moisture resistant) plus glass wool interior layers for freezers and chillers. Q: Can you insulate cryogenic pipelines like liquid nitrogen? A: Yes. Glass wool and calcium silicate jackets protect low-temperature lines such as refrigeration and liquid-nitrogen piping from heat ingress. Q: Do you supply refrigerated transport insulation? A: Yes. Insulation layers for cold-chain vehicles and refrigerated equipment maintain stable low temperatures in transit. Q: What temperature can rock wool handle in cold service? A: Hydrophobic rock wool performs reliably down to about -50 °C when installed with a continuous vapour barrier and metal jacketing. That covers most cold rooms, chilled water and industrial cold ductwork. Below -50 °C, aerogel or cellular glass is the better primary choice; rock wool then appears only as an elastic buffer layer in tank construction. Q: What standards apply to LNG and cryogenic insulation? A: LNG facilities follow NFPA 59A and shipborne carriers follow the IMO IGC Code; mineral wool for industrial pipe and equipment is specified under EN 14303 and cellular glass under ASTM C552. In every case the governing rule is moisture control — a continuous warm-side vapour barrier decides whether the system survives. ### Concentrated Solar Power URL: https://www.rosetexwool.net/applications/csp/ High-temperature insulation for concentrated solar power — receivers, molten-salt tanks and piping, and fire-safety systems using ceramic fiber and calcium silicate. Key benefits: - High-Temp Stability: Ceramic fiber and calcium silicate withstand molten-salt and receiver operating temperatures in CSP plants. - Thermal Efficiency: Receiver and pipe insulation cuts heat loss, raising plant output and capacity factor. - Corrosion Resistance: Chemically stable materials resist molten-salt and tower-environment corrosion. - Long Service Life: Durable linings reduce downtime in high-temperature CSP loops. FAQ: Q: What insulates CSP receivers and towers? A: Ceramic fiber materials rated for the high-temperature operation of receivers on tall solar towers, such as 220 m towers in demonstration plants. Q: How do you insulate molten-salt storage? A: Calcium silicate and ceramic fiber linings protect molten-salt tanks and high-temperature salt piping from heat loss and corrosion. Q: Do you offer integrated fire-thermal solutions? A: Yes. We provide combined fire and thermal insulation packages for CSP equipment, tanks and piping. Q: What temperature can ceramic fiber withstand in CSP? A: Our ceramic fiber insulation is specified for continuous service up to about 1430 °C, covering tower and trough receivers, molten-salt piping and high-temperature equipment. Molten-salt storage and distribution around 565 °C is typically served by mineral wool and calcium silicate, with ceramic fiber used where temperatures exceed 1000 °C. Q: Is your solar-plant insulation non-combustible and corrosion resistant? A: Yes. Our mineral wool and calcium silicate products are A1 non-combustible under EN 13501-1, and the ceramic fiber linings used near molten salt are chemically stable and salt-resistant, which protects both efficiency and plant safety. ### Cement URL: https://www.rosetexwool.net/applications/cement/ Advanced insulation products and systems for thermal management in cement manufacturing including rotary kilns, preheaters, coolers, and ducting. Key benefits: - Reduced Fuel Costs: Nano insulation on kiln shells lowers shell heat loss, directly reducing coal or gas consumption per ton of clinker. - Shell & Tire Protection: Lower shell temperatures protect kiln tires and support rollers from overheating and premature wear. - Worker Safety: Reduced surface temperatures in preheater towers and cooler buildings improve working conditions. - Maintenance Savings: Durable, properly specified insulation extends equipment life and reduces unplanned maintenance. FAQ: Q: What insulation do you recommend for rotary kiln shells? A: We recommend microporous nano insulation boards for the burning zone, which can reduce shell temperatures by 50-80°C in just 5-10mm thickness. For the transition and safety zones, ceramic fiber blanket with stainless steel cladding is a proven solution. Both options minimize added weight on the kiln shell. Q: Do you have products resistant to alkaline cement dust? A: Yes. Our calcium silicate boards are inherently resistant to mildly alkaline environments. For preheater cyclones and ducting exposed to heavy dust-laden gas, we recommend hydrophobic rock wool with full metal cladding to prevent dust ingress into the insulation layer. Q: Can your insulation handle the vibration from kiln rotation? A: Yes. Our kiln shell insulation systems use mechanical fastening with stainless steel banding and welded studs to withstand continuous rotation and vibration. We provide complete installation guidance including stud pattern recommendations for your kiln diameter and RPM. ### Environmental & Dust Removal URL: https://www.rosetexwool.net/applications/environmental-dust-removal/ Specialized insulation and filtration materials for environmental protection equipment including dust collectors, baghouse systems, and emission control devices. Key benefits: - Acid Dew Point Control: Proper insulation keeps duct wall temperatures above acid dew point, preventing sulfuric and hydrochloric acid condensation that causes rapid corrosion. - Energy Efficiency: Minimized heat loss maintains optimal flue gas temperature for downstream pollution control equipment. - Extended Equipment Life: Corrosion-resistant insulation systems reduce maintenance frequency on baghouses, precipitators, and ducting. - Environmental Compliance: Reliable insulation helps maintain consistent emissions control performance for regulatory compliance. FAQ: Q: What insulation prevents acid dew point corrosion in baghouses? A: We recommend hydrophobic rock wool or ceramic fiber blanket with proper cladding and vapor barrier to keep duct and housing wall temperatures above the acid dew point. For coal-fired applications, we typically design for a minimum 25°C margin above the calculated dew point. Contact us for a system recommendation based on your fuel sulfur content and operating temperature. Q: Do you also supply filtration media? A: While our primary focus is thermal insulation, we can supply ceramic fiber filtration media and related products through our partner network. Please contact us to discuss your filtration requirements and we will recommend the most suitable option. Q: Can your insulation withstand the vibration from pulse-jet cleaning? A: Yes, our insulation systems use mechanical fastening with welded pins and speed clips to withstand baghouse pulse-jet vibration. We recommend rock wool blanket with wire mesh reinforcement for high-vibration areas, secured with stainless steel washers and clips on a 300mm grid pattern. ### Iron & Steel URL: https://www.rosetexwool.net/applications/iron-steel/ Steel production temperatures reach up to 1600°C. Thermal insulation refractory materials are critical to protecting equipment, reducing energy waste, and ensuring consistent output in blast furnaces, hot blast stoves, ladles, tundishes, and reheat furnaces. Key benefits: - Energy Cost Reduction: Efficient furnace linings reduce fuel consumption in continuous steelmaking operations. - Extended Campaign Life: Low-shrinkage ceramic fiber modules maintain lining integrity through repeated thermal cycles. - Faster Turnaround: Rapid installation of pre-assembled modules shortens furnace reline downtime. - Consistent Product Quality: Uniform furnace temperatures enabled by reliable insulation lead to consistent steel chemistry. FAQ: Q: What insulation do you recommend for hot blast stove domes? A: We recommend high-purity ceramic fiber modules (HP or HA grade) with IFB backup for hot blast stove domes operating at 1200-1350°C. Our engineers can help calculate lining thickness based on your target shell temperature and operating conditions. Q: Do your ceramic fiber products withstand reducing atmospheres? A: Our standard ceramic fiber products perform well in oxidizing and neutral atmospheres. For strong reducing atmospheres (e.g., hydrogen-rich environments), we offer specially formulated products with controlled organic content. Please contact us to discuss your specific atmosphere conditions. Q: Can you provide pre-assembled modules with anchors? A: Yes, we supply pre-assembled ceramic fiber modules with stainless steel (304/310/Inconel) anchor systems. Specify your furnace shell material and operating temperature for anchor recommendations. ### Power Generation URL: https://www.rosetexwool.net/applications/power-generation/ Amid global energy transition and carbon-reduction targets, the power generation industry must balance operational efficiency with safety and environmental responsibility. Rosewool delivers high-temperature insulation for boilers, steam turbines, HRSGs, flue-gas ducts, substations, nuclear facilities, offshore wind platforms and energy storage stations — with rock wool, ceramic fiber and calcium silicate performing reliably from -268°C up to 1000°C and beyond. Key benefits: - Improved Heat Rate: Superior insulation reduces heat loss from boilers and piping, directly improving plant heat rate and fuel efficiency. - Personnel Protection: Low surface temperatures on hot equipment protect operators and maintenance crews in high-traffic plant areas. - Rapid Outage Turnaround: Pre-fabricated modules and removable blankets speed up boiler and turbine maintenance during planned outages. - Emissions Compliance: Effective SCR and FGD insulation maintains optimal operating temperatures for NOx and SOx reduction systems. FAQ: Q: What insulation do you recommend for HRSG ductwork? A: We recommend mineral wool board or blanket with stainless steel lagging for HRSG casing and ductwork. For high-temperature areas near the gas turbine exhaust, ceramic fiber blanket provides the necessary temperature resistance. Our team can help size and specify for your HRSG configuration. Q: Can you supply removable insulation blankets for turbines? A: Yes, we manufacture custom removable/reusable insulation pads for gas turbine casings, steam turbine valve chests, and associated flanges and fittings. Send us your equipment drawings for a quotation. Q: Do you have insulation for district heating networks? A: Yes. Our rock wool pipe sections and calcium silicate pipe insulation are widely used in district heating. We provide pre-formed sections in standard and custom diameters with aluminum or galvanized steel cladding options. Q: Can rock wool be used in nuclear power plant insulation? A: Yes. For nuclear islands and conventional islands we supply low-chloride rock wool (chloride ≤10 mg/kg) that avoids stress corrosion of austenitic stainless steel, with A1 fire rating and long-term stability at 600°C+ for main steam pipes, valve chests and cable trenches. Q: Is rock wool suitable for offshore wind platform insulation? A: Yes. Water-repellent rock wool (hydrophobicity ≥98.5%) combined with epoxy anti-corrosion coatings performs reliably on platform steam lines, nacelles and transformer cabinets in high-humidity, salt-spray offshore environments, with a service life of 15+ years. Q: How does rock wool improve fire safety in energy storage stations? A: Rock wool fire boards (thickness ≥50 mm) form A-class fire separations in battery compartments and line cable trenches, containing thermal runaway and preventing fire spread between energy storage units. ### Building URL: https://www.rosetexwool.net/applications/building/ Thermal and fire insulation for buildings — external walls, roofs, fire compartments, pipe and acoustic systems using rock wool, glass wool, ceramic fiber and calcium silicate. Key benefits: - Energy Cost Savings: External wall and roof insulation cuts heating and cooling loads, lowering overall building energy consumption. - Fire Safety Compliance: A-class non-combustible rock wool and calcium silicate deliver fire ratings exceeding 3 hours for firewalls, fire doors and fire barriers. - Acoustic Comfort: Glass wool panels and ceiling tiles absorb sound in theaters, meeting rooms and HVAC plenums for quieter interiors. - Long Service Life: Stable, moisture-resistant boards reduce maintenance and extend the service life of the building envelope. FAQ: Q: Which insulation is best for high-rise exterior walls? A: A-class non-combustible rock wool boards are the standard choice for tall-building external walls, combining fire safety with low thermal conductivity of about 0.03-0.04 W/m·K. Q: Can these materials serve as fire barriers? A: Yes. Rock wool fire barriers and calcium silicate core boards achieve fire ratings above 3 hours for firewalls, fire doors and fire partitions. Q: Do you supply acoustic insulation solutions? A: Yes. Glass wool panels and acoustic ceiling tiles provide sound absorption for auditoriums, meeting rooms and ventilation ducts. ### Aerospace & Defense URL: https://www.rosetexwool.net/applications/aerospace-defense/ Lightweight, high-reliability aerospace insulation and fire barrier insulation for defense — aircraft cargo fire barriers, rocket engine shields, spacecraft re-entry blankets, ship fire divisions, and nuclear-spec radiation-hardened insulation for sensitive defense electronics. Key benefits: - Extreme Heat Protection: Ceramic fiber shields rocket engines, exhausts and landing gear from transient temperatures up to 1700°C. - Lightweight Reliability: Low-density fiber and composite structures meet stringent aerospace weight, reliability and service-life requirements. - Fuel & System Safety: Insulation on fuel tanks and electrical enclosures stabilizes temperatures and prevents thermal runaway. - Long Service Life: Durable, radiation-tolerant materials extend component life in demanding defense environments. - Fire Barrier Insulation: Aircraft cargo-hold and engine fire barrier insulation from A1 rock wool and calcium silicate partitions, plus ceramic fiber for hot zones up to 1700°C. - Radiation & Nuclear Spec: Radiation-tolerant, nuclear-spec thermal insulation for defense electronics and reactor-adjacent systems, combining thermal stability with radiation resistance. FAQ: Q: What insulation is used for rocket engine components? A: Ceramic fiber blankets and boards with transient temperature resistance up to 1700°C, plus multilayer composites for re-entry thermal shields and suit liners. Q: Can you provide hypersonic thermal seals? A: Yes. Braided spring-ceramic fiber thermal seal assemblies (developed by space agencies) withstand around 900°C for spacecraft and X-series vehicles. Q: Do you supply aircraft fire barriers? A: Yes. Calcium silicate partitions between cabin and cockpit, and rock wool cargo-compartment fire layers, meet aviation fire-rating needs. Q: What is aerospace fire barrier insulation? A: It is the insulation that contains a fire within a designated zone on an aircraft or defense platform — typically A1 rock wool for cargo-hold liners, calcium silicate partitions for cabin boundaries, and ceramic fiber where temperatures reach 1700°C. It must be lightweight, non-combustible, and hold its shape under vibration. Q: What is aerospace nuclear insulation? A: Radiation-hardened thermal insulation specified for nuclear-powered vessels, reactor-adjacent systems, and rad-tolerant defense electronics. It combines thermal stability with low outgassing and radiation resistance, usually built from ceramic fiber or mica-based composites. ### Pipe Insulation URL: https://www.rosetexwool.net/applications/piping/ Rosewool pipe insulation guide: compare insulation types for piping - ceramic fiber, rock wool, calcium silicate, glass wool and aerogel. Selection by temperature with ASTM, EN and ISO standards. A1 non-combustible, CUI-resistant. Key benefits: - Lower Energy Loss: Pre-formed pipe sections and blanket wraps cut heat loss on steam and process lines by up to 40%, reducing fuel and pumping cost. - Corrosion Under Insulation: Hydrophobic rock wool and proper vapor barriers and jacketing prevent moisture ingress that drives CUI on piping. - Condensation & Freeze Control: Sealed systems on chilled-water and cryogenic lines stop sweating and freeze damage year-round. - Personnel Safety: A1 non-combustible materials and lower surface temperatures protect workers and meet surface-temperature safety limits. FAQ: Q: What are the main types of pipe insulation? A: The three primary categories are pre-formed rigid pipe sections (rock wool, calcium silicate, glass wool), flexible blanket or wrap (ceramic fiber, rock wool, glass wool), and aerogel blankets. Pre-formed sections suit straight runs and fittings; blankets follow irregular shapes such as valves and flanges; aerogel delivers thin, high-temperature performance where space is tight. Q: How do I choose pipe insulation by operating temperature? A: Match the continuous service temperature to the material: glass wool from -120 to 400 C, rock wool up to 650 C, calcium silicate up to 1100 C, ceramic fiber 1100-1430 C, and aerogel up to 1000 C. Use the selection table above as a starting point, then confirm with the relevant ASTM or EN specification. Q: What is the difference between pre-formed pipe sections and blanket wrap? A: Pre-formed sections are molded hollow cylinders that clip around standard pipe sizes for a neat, dimensionally stable finish on straight runs. Blanket wrap is a flexible roll cut on site to fit large diameters, valves, flanges, and elbows that pre-formed sections cannot cover. Q: Which insulation is best for high-temperature steam pipes above 650 C? A: For headers above 650 C, use calcium silicate pipe sections (continuous service up to 1100 C) or ceramic fiber blanket (1100-1430 C). Ceramic fiber is preferred where wrapping irregular high-temperature geometry is required. Q: How do you prevent corrosion under insulation (CUI) on pipes? A: Specify hydrophobic materials such as rock wool, install a continuous vapor barrier and protective jacketing on sub-ambient lines per ASTM C921, and keep the system sealed so moisture cannot reach the pipe surface. Regular inspection of jacket integrity is essential. Q: What standards apply to industrial pipe insulation? A: Key standards include ASTM C547 (mineral fiber pipe insulation), ASTM C533 (calcium silicate), ASTM C1393 (mineral fiber blanket pipe wrap), EN 14303 (factory-made mineral wool for pipe and equipment), and ISO 8497 (flexible blanket-type pipe insulation). Fire performance is covered by EN 13501-1 (A1) and ASTM E84 (Class A). ### Petrochemical URL: https://www.rosetexwool.net/applications/petrochemical/ Rosewool A1 non-combustible rock wool pipe sections, ceramic fiber & calcium silicate for petrochemical plants: 450-650°C piping, furnaces, tanks. CUI-resistant, ASTM/EN-rated. Key benefits: - Lower Energy Loss: High-performance ceramic fiber and aerogel reduce heat loss from process equipment by up to 40%, cutting fuel consumption. - Corrosion Under Insulation: Hydrophobic rock wool and proper system design prevent moisture ingress that causes CUI in petrochemical piping. - Reduce Unplanned Shutdowns: Durable refractory linings withstand thermal cycling without spalling, extending campaign lengths. - Personnel Safety: Low shell temperatures protect workers and meet OSHA surface temperature requirements in operating areas. FAQ: Q: What insulation is best for high-temperature petrochemical piping? A: Rock wool pre-formed pipe sections are the workhorse for process and steam piping up to 650°C continuous (800°C short-term), rated A1 non-combustible per EN 13501-1. For furnace linings and reactor sections above that range we specify ceramic fiber modules and calcium silicate. All are selected to API/NFPA fire-safety standards. Q: How do you prevent corrosion under insulation in refineries? A: We use hydrophobic rock wool with integral water repellent (water repellency ≥98%) combined with proper cladding, sealants and vapor barriers. We also recommend periodic inspection and can advise on CUI-resistant coating systems for the substrate. Q: Do you provide insulation for reformer and cracker furnaces? A: Yes. Our ceramic fiber modules and blankets line reformer and cracker furnaces, with pre-assembled modules and various anchor systems for fast installation and stable performance through rapid thermal cycling. Q: Which rock wool products are best for refinery piping and vessels? A: For refinery piping we use pre-formed rock wool pipe sections; for vessels, tanks and large equipment, rigid rock wool board; for valves and flanges, rock wool board with removable insulation covers. All are A1 non-combustible and available in hydrophobic grades for CUI-prone service, conforming to ASTM C547 and EN 14303. Q: Can you insulate cryogenic and LNG storage tanks or flare lines? A: Yes. For LNG and cryogenic tanks (down to -162°C) we design layered systems with rock wool or calcium silicate on the ambient side plus vapor barriers, cutting cold loss 15-20%. Flare headers and relief lines are insulated with rock wool or ceramic fiber matched to the expected temperature and fire scenario. Q: Do you supply insulation for hydrocracking, delayed coking and FCC units? A: Yes. We provide ceramic fiber modules and blankets for high-temperature reactor and furnace linings in hydrocracking, delayed coking and FCC service, with rock wool pipe sections and calcium silicate for the associated piping and steam systems. Pre-assembled modules shorten furnace downtime during turnarounds. ### Traffic & Fire Protection URL: https://www.rosetexwool.net/applications/traffic-fire-protection/ Fire-rated insulation materials for building fire protection, cable shaft sealing, and transportation applications meeting international fire resistance standards. Key benefits: - Certified Fire Performance: Products tested to international standards — CE-marked rock wool with Euroclass A1 reaction to fire classification. - No Smoke or Droplets: Rock wool and ceramic fiber produce no smoke and no burning droplets when exposed to fire — critical for safe evacuation. - Compartment Integrity: Properly installed fire stopping maintains the fire-resistance of rated walls and floors, preventing fire spread. - Asset Protection: Fire-rated cable tray protection keeps critical circuits operational during a fire for safe shutdown and emergency response. FAQ: Q: What fire rating can rock wool board achieve? A: Depending on thickness and installation method, rock wool board systems can provide 30 minutes to 4 hours of fire protection for structural steel, as tested to BS 476 Part 21 or EN 13381-8. We recommend consulting local fire engineering codes for required thickness. Q: Is ceramic fiber acceptable for building fire protection? A: Ceramic fiber is primarily used in industrial and high-temperature fire protection applications. For general building fire protection, rock wool is more commonly specified due to its bio-solubility and broader regulatory acceptance. We can advise on the most appropriate product for your application and jurisdiction. Q: Do you provide fire-rated duct insulation systems? A: Yes. We supply rock wool board and blanket systems for both horizontal and vertical fire-rated ventilation ducts tested to EN 1366-1 and BS 476 Part 24. Contact us with your duct dimensions and required fire rating period. ## News & Articles Total articles: 83 ### Rock Wool Blanket Buying Guide: Density, Specs, Standards & Inspection URL: https://www.rosetexwool.net/news/rock-wool-blanket-buying-guide/ 2026-09-22 | Author: Rosetexwool Editorial | Category: industry insight Summary: A buyer's guide to rock wool blanket: product forms, density selection by application, ASTM C553 / EN 14303 standards, datasheet red flags, and arrival inspection. Rock wool blanket is one of the most requested industrial insulation products in global RFQs — and one of the most frequently mis-specified. The single word "blanket" hides a family of products with different fiber orientations, facings, densities, and temperature limits, and buyers who quote on the name alone routinely receive material that does not fit the application. This guide is written for purchasing decisions: what to specify, which standards should sit behind your purchase order, how to read a datasheet like a buyer, and what to check when the rolls arrive. One Name, Several Different Products "Rock wool blanket" is not a specification — it is a product family. Before comparing prices, define which construction you are actually buying: Product form | Construction | Typical applications | Key buying point | Flexible blanket (parallel-fiber) | Soft roll, fibers primarily parallel to the faces | Large-diameter pipes, tanks, vessels, irregular surfaces, voids | Conforms to curvature; not load-bearing | Wired mat (stitched / wire mesh) | Blanket locked by wire mesh and stitching on one or both faces | High-temperature pipes, flues, boilers, tanks | Mesh material, mesh size, and stitch thread temperature rating must be stated | Glass-mesh faced blanket | Blanket with glass-fiber mesh facing | Facings where tear resistance and handling strength matter | Facing changes fire and vapor behavior — test the finished product | Board (rigid / semi-rigid) | Higher density, higher compressive strength | Flat walls, tank shells, roofs, acoustic linings | Different fiber orientation and mechanics — never price against blanket per kilo | Pipe sections (pre-formed) | Vertical-fiber, pre-cut to pipe diameter | Small and medium-diameter piping | Defined by inner diameter and wall thickness, not by blanket specs | The distinction is not pedantic. ASTM C553, the reference US specification for commercial and industrial mineral fiber blanket, explicitly covers material whose fibers run primarily parallel to the principal surfaces — and explicitly excludes pre-formed vertical-fiber pipe and tank coverings, which belong under their own product standards. In Europe, EN 13162 covers factory-made mineral wool for building applications, while EN 14303 covers building equipment and industrial installations. Ordering "blanket" against the wrong standard family is the most common root cause of rejected shipments. Typical Specification Ranges at a Glance Commercially, industrial rock wool blanket is bought within these working ranges — always confirmed against the specific product datasheet: Parameter | Typical commercial range | Buyer's note | Density | 60–150 kg/m³ | Nominal value ± tolerance; state whether wire mesh weight is included | Thickness | 25–100 mm | Multi-layer build-ups (e.g. 2 × 50 mm) are standard above 50 mm | Roll width | 1.0–1.2 m (600 mm common in wired mats) | State minimum guaranteed roll length, not just nominal length | Continuous service temperature | up to about 650 °C hot face | Not the melting point — see the datasheet section below | Thermal conductivity | ~0.035–0.045 W/(m·K) at 25 °C mean | Always ask for the λ(T) curve, not the single 25 °C figure | Facing options | Unfaced, glass cloth, aluminum foil, wire mesh | Facings change fire, vapor, and temperature performance | Our rock wool blanket product page lists the standard grades and dimensions we ship; wired mat and glass-mesh faced variants are specified separately for high-temperature and mechanical-strength applications. Which Standards Should Sit Behind the PO Match the standard to the end use before comparing offers: - ASTM projects (North America and ASTM-specified contracts): ASTM C553 governs commercial and industrial mineral fiber blanket, covering classification, physical properties, dimensions, maximum use temperature, thermal resistance, water vapor sorption, flexibility, and surface burning. Pre-formed pipe and tank coverings fall outside it. - EU building products: EN 13162 with a Declaration of Performance (DoP) and CE marking under the Construction Products Regulation. The standard defines test methods — the required performance levels for a specific application come from the project specification and local regulations. - EU industrial installations: EN 14303 governs factory-made mineral wool for building equipment and industrial installations (blankets, wired mats, boards, pipe sections). - Fire classification: EN 13501-1 in Europe, ASTM E84 surface-burning characteristics in the US. Both classify the finished product as tested — an unfaced rock wool core result cannot be transferred to a foil-faced roll. One CE-related point that saves disputes: CE marking proves the DoP declaration, not fitness for every use. If your application is industrial equipment rather than a construction product, ask for EN 14303 evidence and project-specified tests — do not accept a building-product CE file as blanket approval. Density Selection: Matching Weight to Application Density is the lever that trades flexibility against mechanical strength. Buying "80 kg/m³ blanket" without a rationale is how the wrong product arrives: Application | Recommended density | Why | Large tank shells, domes, large-diameter pipework | 60–80 kg/m³ | Conformability and coverage per roll matter more than compression strength | General industrial equipment, flues, ducts | 80–100 kg/m³ | Balanced thermal and mechanical performance | Machinery enclosures, acoustic treatment, moderate loads | 100–150 kg/m³ | Higher density improves sound absorption and surface durability | Flat surfaces, walking areas, external walls | Use board, not blanket | Compression and fixings demand rigid products — see our rock wool board | State density as finished-product value with tolerance, sampling position, and whether mesh or facing weight is included. Low-ball quotations are frequently achieved by dropping density — verify per batch, not per brochure. Reading the Datasheet Like a Buyer Four parameters deserve contractual attention: Thermal conductivity is a curve, not a number. λ rises with temperature. A single 25 °C figure is marketing; high-temperature heat-loss calculations need declared λ values at the relevant mean temperatures, with test method and product construction stated. If a supplier offers only a 25 °C minimum λ, treat the high-temperature calculation as unverified. Maximum service temperature is bound to conditions. For rock wool blanket the meaningful figure is continuous service temperature — about 650 °C for standard industrial grades — not the ~1000 °C melting point of the fiber itself. A valid claim binds hot-face temperature, facing construction, exposure duration, and thickness. Ask for hot-surface performance evidence (e.g. linear shrinkage and visual condition after sustained hot-face exposure per the relevant test method) for the exact product, density, and facing you are buying. Dimensions need tolerances and minimums. Specify nominal thickness with tolerance, roll width, and — critically — minimum guaranteed roll length per roll, plus the number of joints allowed per roll. Under-length rolls discovered at installation are a classic hidden cost. Water-related claims split into two different properties. Water repellency (the fiber matrix resisting liquid water) and water vapor permeability are different things. ASTM C1104 measures vapor sorption of the unfaced core only — it says nothing about the facing or a system's vapor performance. For below-ambient service, the vapor barrier is a separate, continuous sealing design — never the blanket itself. Our cryogenic pipe insulation guide covers the condensation-control system design in depth. Stainless Steel Contact: a Corrosion Clause Worth Having Where blanket touches austenitic stainless steel, request evidence against ASTM C795: the insulation must pass the preproduction stress-corrosion test (ASTM C692) with chemical composition controlled per ASTM C871. This applies to the blanket, the facing, the mesh, and any adhesives in contact. It is a standard clause in petrochemical and power projects, and it is cheap to demand at RFQ stage and expensive to litigate after pitting appears. Quality Inspection: Three Layers of Acceptance Layer 1 — documents and identity. Purchase order vs packing list; manufacturer, model, origin; batch numbers and dates; labels and datasheets; DoP/CoC where required; certificates matched to the actual model (not an "equivalent" product). Layer 2 — arrival condition. Packaging integrity, water staining, crushed rolls, torn facings, delaminated foil, rusted mesh, loose stitching, short rolls, mixed batches. Photograph before unpacking. Damaged packaging does not auto-reject the batch — sample-test density, thickness, and moisture in quarantine first. Layer 3 — performance verification. For each batch: thickness at multiple positions, density (state whether mesh included), and for critical high-temperature or stainless-steel applications, third-party testing of hot-face performance and chemistry. First orders, new batches, and any process change from the supplier should trigger re-testing. Fiber quality sits behind these checks: well-processed rock wool blanket shows low shot (unfiberized particle) content, resilient fibers that recover after compression, and consistent texture without layering. These are inspection observations — make them measurable in your acceptance criteria rather than leaving them as opinions. Application-Specific Buying Notes - Industrial piping: for small and medium diameters, pre-formed pipe sections usually beat blanket on fit and speed; blanket wins on large diameters, valves, flanges, and irregular runs. Specify inner-diameter basis, thickness, longitudinal-joint staggering, and securement. Our industrial pipe insulation materials guide and rock wool pipe specs cover the section-by-section choices. - Tanks and vessels: prioritize coverage per roll, weather protection, and uplift from wind; buy on cost per square meter of compliant thickness, not per kilo. - High-temperature equipment: build a temperature ladder — if the hot face exceeds ~650 °C, rock wool blanket belongs behind a hot-face layer (or the duty moves to ceramic fiber), never as the exposed working layer. Our metallurgy applications guide shows the layering logic in furnace environments. - Building envelopes: this is a system purchase — fixings, render, fire breaks, and wind loading dominate. Use building-grade board/external wall systems; our external wall installation guide walks the system requirements. Red Flags in Quotes and Datasheets - λ quoted only at 25 °C for a high-temperature duty. - "Withstands 1000 °C+" — that is the melting point, not the continuous service temperature. - Density stated without tolerance, sampling basis, or mesh-inclusion clarity. - Certificates referencing a different model, facing, or density than the quote. - "Waterproof" used to imply a vapor barrier for cold service. - Prices that win by dropping density, thickness, or guaranteed roll length. For the broader material family — boards, pipe sections, and where each fits — start from our rock wool insulation hub. RFQ Checklist: One Line per Configuration A quotable RFQ line looks like this, not like "rock wool blanket, 50 mm": - Product form: flexible blanket / wired mat / faced blanket — with facing type per side. - Standard: ASTM C553, EN 14303, or project-specified equivalent, fire classification per the finished product. - Dimensions: thickness (± tolerance), width, minimum guaranteed roll length, joints per roll. - Density: nominal ± tolerance, finished-product basis, mesh/facing weight stated. - Thermal: λ values or curve at stated mean temperatures, test method. - Temperature: continuous service temperature with hot-face conditions, evidence for the exact construction. - Special: stainless-steel contact chemistry (ASTM C795/C692/C871) where applicable; vapor-sealing responsibilities assigned separately for cold service. - Documents: CoC, batch traceability, DoP where required, language. Buy rock wool blanket the way the standards read it — a defined construction under a defined standard for a defined duty — and the quotes you receive finally become comparable. When you are ready to compare a specific grade, the rock wool blanket product page lists our standard configurations, and our team quotes to your exact RFQ line. FAQ: Q: What density rock wool blanket should I buy? A: Match density to the application: 60–80 kg/m³ for large tank shells and large-diameter pipework where conformability matters, 80–100 kg/m³ for general industrial equipment and flues, and 100–150 kg/m³ for machinery enclosures and acoustic work. Flat or load-bearing surfaces need rock wool board, not blanket. Always state density as a finished-product value with tolerance, and clarify whether mesh weight is included. Q: What is the maximum service temperature of rock wool blanket? A: Standard industrial rock wool blanket grades carry a continuous service temperature of about 650 °C at the hot face. The fiber's melting point near 1000 °C is not a service rating. Above roughly 650 °C hot face, rock wool belongs behind a hot-face layer or the duty moves to ceramic fiber products. Q: Is rock wool blanket waterproof? A: Rock wool is water-repellent — the fiber matrix resists liquid water — but repellency is not a vapor barrier. ASTM C1104 measures vapor sorption of the unfaced core only. For below-ambient or cold service, condensation control requires a separate, continuous vapor-barrier system with sealed joints; the blanket alone never provides it. Q: What is the difference between rock wool blanket and rock wool board? A: Blanket is a flexible parallel-fiber roll that conforms to tanks, vessels, and irregular surfaces, but it is not load-bearing. Board is rigid or semi-rigid, denser where needed, and carries compression — which is why walls, roofs, and any surface subject to loads or fixings are specified in board. They follow different product standards and should be priced separately, never per kilo against each other. Q: Which standard applies to rock wool blanket: ASTM C553 or EN 14303? A: Follow the end use and the project's jurisdiction. ASTM C553 governs commercial and industrial mineral fiber blanket in the ASTM system — it excludes pre-formed vertical-fiber pipe and tank coverings. In Europe, EN 13162 covers building products (with DoP and CE marking) and EN 14303 covers building equipment and industrial installations. Match the standard to the application, and have fire classification tested on the finished, faced product. Q: Can rock wool blanket be used on austenitic stainless steel? A: Yes, if it is qualified. Require compliance with ASTM C795, which means passing the ASTM C692 preproduction stress-corrosion test with chemistry controlled per ASTM C871. The requirement covers the blanket core, facing, mesh, and any adhesives in contact with the steel — a standard clause for petrochemical and power projects. ### Mid-Autumn Festival 2026: Holiday Notice & Warm Wishes URL: https://www.rosetexwool.net/news/mid-autumn-festival-2026-holiday-notice/ 2026-09-22 | Author: Rosetexwool Editorial | Category: company news Summary: Rosetexwool Insulation will be closed on Friday, 25 September 2026 for the Mid-Autumn Festival. Festival traditions, our holiday notice, and warm wishes to our global partners. The Mid-Autumn Festival — one of the most cherished holidays in the Chinese calendar — falls on Friday, 25 September 2026 this year. Our office and factory will be closed for one day on that date, and our team will join families across China to celebrate the harvest moon. Inquiries received during the holiday will be answered within 24 hours of reopening. From all of us at Rosetexwool Insulation Refractory Co., Ltd., warm wishes to our partners, customers, and friends around the world. A Festival Three Thousand Years in the Making The Mid-Autumn Festival (Zhongqiu Jie) is celebrated on the 15th day of the eighth month of the traditional Chinese lunar calendar — the night when the moon is at its fullest and brightest. Its roots reach back more than three thousand years, to ancient moon-worship ceremonies and autumn harvest thanksgiving rites. By the Tang and Song dynasties, moon viewing had grown into a nationwide celebration, and today the festival stands alongside the Lunar New Year as one of the most important family holidays in Chinese culture. The full moon is the heart of the festival. In Chinese tradition, a round shape expresses completeness and unity, so the full moon became a symbol of family reunion — a meaning that carries into everything associated with the day, from the food on the table to the lanterns in the evening sky. Mooncakes, Lanterns, and the Legend of Chang'e The most iconic tradition is sharing mooncakes: round, richly filled pastries whose shape echoes the full moon. A mooncake is traditionally cut into equal pieces and shared among family members, each slice a small act of togetherness. Classic fillings include lotus seed paste, red bean paste, and mixed nuts, often with a salted duck egg yolk at the center to represent the moon itself. Exchanging boxed mooncakes among relatives, friends, and business partners is an established way of sending good wishes before the festival. Evening customs are just as vivid. Children carry colorful lanterns, parks hold lantern fairs and riddle games, and families gather outdoors or on balconies to admire the moon together. Many of these customs are woven around the legend of Chang'e, the moon goddess who, according to the tale, drifted to the moon where she still watches over the human world — which is why, on this night, looking up at the moon feels a little like greeting an old friend. Seasonal foods complete the table: pomelo for prosperity, osmanthus-flavored treats and wine for the season, and regional specialties that vary from province to province. Our Holiday Arrangement Item | Detail | Holiday | Mid-Autumn Festival 2026 | Closed | Friday, 25 September 2026 (one day) | Reopening | Next business day | Inquiries | Answered within 24 hours of reopening | Shipping schedules for orders already in production are not affected. For urgent matters, please send us an email or leave a message through our website contact form, and our sales team will get back to you promptly after we reopen. Why This Tradition Matters to Us The values behind the festival — reunion, gratitude, and a good harvest — translate naturally into how we run our business. Every year at this time, our production, quality, and export teams travel home to reunite with their families, and they return with the same renewed energy they bring to every shipment. Since 1982, our factory has grown from a local workshop into an exporter of rock wool, ceramic fiber, and calcium silicate insulation serving more than 60 countries — a journey made possible by long-term partners who trust us with their projects, year after year. If you would like to see what that partnership looks like in practice, explore our rock wool insulation, ceramic fiber, and calcium silicate product lines, or start with our rock wool blanket overview for one of our most exported product families. Warm Wishes to Our Global Partners However far apart we are, we will be looking at the same moon. May your projects run smoothly, your harvests be full, and your reunions — wherever and however you hold them — be warm. Happy Mid-Autumn Festival from the entire Rosetexwool Insulation team. FAQ: Q: When is the Mid-Autumn Festival in 2026? A: The Mid-Autumn Festival falls on Friday, 25 September 2026. It is held on the 15th day of the eighth month of the traditional Chinese lunar calendar, so its date on the Gregorian calendar changes each year, usually landing in September or early October. Q: Will the holiday affect my order or quotation? A: Our office and factory are closed for one day only, on Friday, 25 September 2026. Orders already in production are not affected, and inquiries received during the holiday will be answered within 24 hours of reopening. Q: What is the Mid-Autumn Festival and why do people celebrate it? A: It is a traditional Chinese festival over three thousand years old, celebrated on the night of the year's fullest harvest moon. The full moon symbolizes family reunion and completeness, and celebrations include sharing mooncakes, lighting lanterns, and gathering with family — similar in spirit to Thanksgiving in Western cultures. ### Ship Engine Room & Machinery Space Insulation: IMO SOLAS A-60 Guide URL: https://www.rosetexwool.net/news/marine-engine-room-machinery-space-insulation-solas-a60/ 2026-09-21 | Author: Rosetexwool Editorial | Category: industry insight Summary: How A-60 applies to ship engine rooms and machinery spaces: the 140/180 °C limits, approved insulation materials, type-approval, and specification pitfalls. Engine rooms and machinery spaces are the highest fire-risk, highest heat-dissipation zones on any vessel. The boundaries that separate them from accommodation, control stations, and other spaces must hold back fire and heat for a defined period, and for the most demanding boundaries that period is 60 minutes under the A-60 standard. This guide explains what A-60 actually requires for ship engine rooms and machinery spaces, which insulation materials are used and why, and how a compliant system is specified and built. What A-60 Means for a Machinery Space Under SOLAS Chapter II-2 Regulation 3.3, a Class A division is a division formed by steel or equivalent material, suitably stiffened, and insulated with approved non-combustible materials so that it can withstand the standard fire test for 60 minutes. For an A-60 division the back (unexposed) face must stay within two limits for the full 60 minutes: - the average temperature rise must not exceed 140 °C, and - the temperature rise at any single point — including joints and seams — must not exceed 180 °C. At the same time the division must prevent the passage of flame and smoke. The key point that specifiers miss is that A-60 is a property of a complete division (a construction), not of any single slab. A mineral wool board is not "an A-60 material"; it becomes part of an A-60 system only when it is incorporated into a type-approved sample construction with defined thickness, density, stiffener coverage, joint arrangement, fixings, and facing. For the full shipboard fire-division system, see our marine fire insulation standards guide. The Fire It Must Survive — the Standard Time-Temperature Curve The test follows the IMO standard fire curve, where the furnace temperature rises along the relationship T = 345·log10(8t+1) + 20 °C. The control points are demanding: Time | Furnace temperature | 5 min | 576 °C | 10 min | 679 °C | 15 min | 738 °C | 30 min | 841 °C | 60 min | 945 °C | This is the cellulose standard fire used for ship structures — not a hydrocarbon jet-fire curve (that is a separate offshore consideration, covered in our offshore marine insulation guide). The hardest part is the first five minutes, when the furnace jumps to 576 °C; the insulation must keep the unexposed face under the 140/180 °C limits across the entire 60 minutes. Material Options for Engine Room & Machinery Space Boundaries The table below summarises the materials typically used inside machinery-space boundaries and process systems. Temperature and conductivity figures are continuous-service values; the role in an A-60 system depends on type-approval, not on the material alone. Material | Continuous service temp | Thermal conductivity | Role in A-60 / machinery space | Mineral (stone) wool | ≤ 650 °C (melt point > 1000 °C) | ~0.034–0.040 W/(m·K) | Baseline core of most A-60 bulkheads/decks; high-density boards 100–130 kg/m³ | Ceramic fiber | 1100–1430 °C | ~0.06–0.12 W/(m·K) @ 600 °C | Exhaust manifolds, mufflers, high-temp flues, penetration seals | Flexible aerogel blanket | ~650 °C | 0.018–0.021 W/(m·K) | Space-constrained pipes/valves; thin build-up | Microporous insulation | up to 1000–1050 °C | 0.020–0.030 W/(m·K) @ 800 °C | Localised high-temp nodes, LNG fuel-line guards | Glass wool | −120 to 400 °C | 0.032–0.038 W/(m·K) | Acoustic lining, A-0 ducts, accommodation — not a standalone A-60 fire layer | Mineral wool is the workhorse: it is the approved core of the large majority of A-60 bulkheads and decks, it is naturally non-combustible, marine grades are hydrophobic, and it combines thermal and acoustic performance. Our rock wool blanket product page covers typical density and board formats. Ceramic fiber earns its place where temperatures exceed what mineral wool can carry continuously — exhaust runs, boiler uptakes, and turbocharger casings. It must be faced with foil or cloth to control fibre release, and its installation is a recognised health-and-safety activity that requires proper controls. Flexible aerogel blankets deliver the same insulation in a fraction of the thickness, which is valuable in crowded machinery spaces, but they must be combined with an inorganic reinforcement to pass non-combustibility, and the whole composite must be type-approved. Our aerogel insulation overview explains where thin-build solutions make sense. Not Just Class A — Surfaces Above 220 °C and Oil-Wetted Risks A-60 is only part of the story. SOLAS II-2/5.2.1.1 requires that surfaces exceeding 220 °C which may be contacted by leaking flammable liquid must be effectively insulated with non-combustible material. If that insulation is oil-absorbent, or if oil penetration occurs, the surface must be covered with an impervious thin steel plate or equivalent. This is a functional oil-fire-prevention rule, separate from the A-60 division requirement, and it applies to steam lines, hot-oil lines, exhausts, mufflers, boilers, and turbochargers. For exhaust and flue runs, the usual layering is a high-temperature inner layer (often ceramic fiber) plus a foil or metal facing. Pipe penetrations through A-60 boundaries are not solved by insulating the pipe on both sides — each penetration needs its own approved penetration seal, with the component projecting 500 ± 50 mm beyond the division on both the fire and unexposed sides per the IMO fire-test recommendation A.754(18). How an Approved A-60 System Is Built A compliant A-60 boundary is a certified system, not a pile of slabs. The sequence matters: - Type-approval. The whole assembly — core material, thickness, density, stiffener coverage, joints, pins, washers, and facing — is tested as a sample construction and certified by a recognised classification society or flag-state authority. The certificate locks the thickness, density, and fixing spacing. A significant change (a 5 mm thinner layer, a different pin, a different facing) can invalidate the certificate and must be re-approved. - Fixing. Insulation is held by welded studs or pins, typically 6–9 per m², with double-layer staggered joints and high-temperature aluminum foil tape at seams to avoid thermal bridges and flame paths. - Conformity marks. A Wheelmark (MED) is the EU/EEA market conformity mark; whether it applies depends on the flag state. It is not a universal SOLAS certificate, so confirm per project. - Material vs division tests. Non-combustibility is proven under FTP Code Part 1 (ISO 1182, tested around 750 °C). Smoke and toxicity are Part 2, A/B/F divisions are Part 3, and surface/low-flame-spread materials are Part 5. A material certificate alone does not constitute an A-60 division approval. For detailed A-60 thickness build-ups by boundary type, our A-60 marine insulation thickness guide works through the numbers. Choosing by Location Inside the Machinery Space Different surfaces have different goals, and mixing them up is a common error: - A-60 bulkheads and decks: an approved mineral-wool or ceramic-fiber A-60 system, matching the certificate exactly. - Main and auxiliary engine casings: removable non-combustible insulation plus the manufacturer casing; usually not an A-60 target, but must allow maintenance access. - Boiler, flue, and exhaust: high-temperature refractory fiber or composite plus a metal casing that can be removed for inspection. - Steam and hot-oil lines: mineral wool as the primary layer; aerogel where space is constrained. - Fuel-oil lines: protect against touch and oil penetration per the 220 °C rule; add a thin-steel wrap if the insulation is absorbent. - LNG and low-temperature lines: a dedicated low-temperature design — never substituted with an A-60 or ambient-temperature material. - Pump rooms: treated under the relevant cargo-code fire table, with ventilation, hazard zoning, and drainage designed in. Common Specification Mistakes to Avoid - Calling a slab "A-60 material." Correct wording: a non-combustible material incorporated into an approved A-60 division. - Treating ISO 834, EN 1364-1, or ASTM E119 reports as A-60 approval. Those are building-fire standards; an A-60 division needs FTP Code Part 3 / A.754(18) evidence. - Using "classification temperature" as the continuous service temperature for ceramic fiber. Always ask for the definition and the actual continuous rating. - Insulating the pipe but not the support shoe, valve, or penetration end. Those discontinuities are where systems fail. - Substituting a thinner aerogel purely for space without re-verifying the whole assembly against the approved construction. Specifying insulation for a ship engine room or machinery space is a loop that closes only when the regulation, fire-zone plan, type-approval, nominated product, and the classification society's project review all agree. Start from the boundary's required class, choose a material that fits the approved construction, and verify the certificate covers the exact build before anything is installed. FAQ: Q: What temperature rise is allowed for an A-60 division? A: Over the 60-minute standard fire test the unexposed face must not rise more than 140 °C on average, and no single point — including joints — may rise more than 180 °C. The division must also block flame and smoke throughout. Q: Is rock wool an A-60-rated material? A: Mineral (stone) wool is the approved core of most A-60 bulkheads and decks. On its own it is a non-combustible material proven under FTP Code Part 1; it becomes part of an A-60 division only inside a type-approved construction with defined thickness, density, and fixings. Q: What is the difference between A-60 and A-0? A: Both resist fire for 60 minutes, but A-0 requires only integrity and non-combustibility, with no limit on back-face temperature rise. A-60 adds the 140 °C average / 180 °C point insulation limit, which is why A-60 is used where heat transfer to the adjacent space must be controlled. Q: Can aerogel replace mineral wool for A-60? A: Only as part of an approved composite. A flexible aerogel blanket must be combined with an inorganic reinforcement to pass non-combustibility, and the full assembly must carry type-approval — it cannot be substituted piecemeal for a certified mineral-wool system. Q: What does the 220 °C rule mean for machinery spaces? A: SOLAS II-2/5.2.1.1 requires that surfaces above 220 °C which could be contacted by leaking flammable liquid are effectively insulated with non-combustible material, and covered with an impervious thin steel plate or equivalent if the insulation is oil-absorbent. It is a separate oil-fire-prevention rule from A-60. Q: Does every project need its own type approval? A: The insulation system needs a valid type-approval that matches the actual construction — thickness, density, stiffeners, joints, fixings, and facing. The classification society then confirms that approval against the specific vessel's plans during project review. ### Cement Kiln & Rotary Furnace Refractory Lining Selection URL: https://www.rosetexwool.net/news/cement-kiln-rotary-furnace-refractory-lining/ 2026-09-21 | Author: Rosetexwool Editorial | Category: industry insight Summary: Zone-by-zone refractory lining selection for cement kilns and rotary furnaces, with clear boundaries for ceramic fiber and calcium silicate roles in backup insulation. Selecting a refractory lining for a cement kiln or rotary furnace is not a single-temperature decision. A rotating shell imposes conditions no static furnace sees: continuous mechanical flexing (shell ovality), abrasive material charge, coating that builds up and breaks away, and an axial temperature and chemistry gradient running from the feed end to the discharge. This guide breaks the kiln into its operating zones, explains which refractory roles each zone demands, and — critically for insulation buyers — clarifies where ceramic fiber and calcium silicate belong (and where they do not). Why a Rotary Kiln Lining Is Different from a Static Furnace In a static furnace, a lining can often be designed around temperature and atmosphere alone. In a rotary kiln, the lining is a rotating structural ring. Three loads act on it simultaneously: - Thermal load — flame radiation, hot gas convection, and conduction through coating, brick, and shell. - Mechanical load — the charge rolls and slides across the lining with every revolution; the shell deforms elliptically between tyres, putting the brick ring under cyclic compression and shear. - Chemical load — alkalis, sulfur, and chlorides volatilize in the hot zone, travel with the gas stream, condense in cooler zones, and re-enter the bed with the feed. This internal circulation concentrates salts at brick joints and pores. A lining chosen on classification temperature alone ignores two of these three loads — which is why like-for-temperature substitutions so often fail early. Lining Zones Along the Kiln Axis Modern dry-process cement kilns are lined zone by zone. Each zone pairs a characteristic temperature range with a dominant failure mechanism, and the working-layer choice follows from that pairing: Zone | Typical process temperature | Dominant stresses | Working-layer direction | Kiln inlet / preheating | 800–1200 °C | Alkali, sulfur, chloride condensation; coating build-up | Dense alkali-resistant brick or abrasion-resistant high-alumina brick | Upper transition | 1200–1350 °C | Coating formation and loss; thermal cycling; salt deposition | Magnesia-alumina spinel or toughened high-alumina brick | Sintering (clinkering) | 1400–1500 °C | Clinker liquid-phase infiltration; coating stability | Basic brick (magnesia-spinel or dolomite) that takes a stable clinker coating | Lower transition | 1250–1400 °C | Temperature drop, clinker abrasion, local coating instability | Spinel or wear-resistant high-alumina brick | Cooling zone / kiln discharge | 1100–1300 °C | Quench, falling clinker impact, secondary-air disturbance | Wear-resistant brick, or steel-fiber-reinforced castable precast shapes at the nose | Two engineering facts are worth remembering when arguing for lining investment: industry studies of large kilns report shell surface temperatures of roughly 350–400 °C in the transition and sintering zones, with associated heat losses on the order of 8–15% of total heat input in poorly maintained sections. The first energy-saving move is not adding insulation — it is restoring the hot-face lining and a stable clinker coating. The Rule That Matters Most: Working Layer and Insulation Layer Do Not Swap The single most common specification error we see in rotary furnace enquiries is treating a high classification temperature as permission to use a soft insulation product on the hot face. It is not. Refractory linings work as a layered system: - The working layer (dense brick, castable, or precast shapes) takes the flame, the charge, and the chemistry. It carries mechanical load and forms the structural face. - The insulation layer (ceramic fiber, calcium silicate, insulating firebrick) sits behind the working layer in suitable locations, reducing heat flow to the shell. It must never be placed where the charge rolls, where flame impinges, or where salts condense. Ceramic fiber products (blanket, board, folded modules) bring low thermal conductivity, low heat storage, and fast heat-up — ideal for the static ancillary equipment around the kiln: kiln hood, smoke chamber, tertiary air duct, preheater vessels, and repair doors. In these stationary enclosures, fiber modules anchored to the steelwork cut heat storage and shorten startup cycles. They are not used as the load-bearing lining of the rotating barrel itself: continuous rotation, charge shear, and vibration will compact, shed, and destroy an unprotected fiber hot face. Our ceramic fiber module product page covers anchor systems and module formats for static furnace linings. Calcium silicate board is the complementary cold-face material: rigid, dimensionally stable, machinable, and strong in compression — well suited as a hard backup behind dense working layers in static equipment, and as protective pack-off material around nozzles and openings. Grades are specified per recognized standards such as ASTM C533 or EN 14306, with standard grades serviceable to about 650 °C and high-temperature grades to roughly 1000–1100 °C. Two cautions: calcium silicate absorbs moisture (wet board loses insulation value and must be dried), and it must never be used as the hot-face load-bearing layer in a rotary barrel. Our calcium silicate board product page lists grades and typical properties. For a side-by-side comparison of the two materials, see ceramic fiber vs. rock wool for furnace applications and our refractory board selection guide. Chemistry: the Alkali Cycle That Kills Linings Early Volatile species drive much of the premature lining loss in cement kilns. Potassium, sodium, chlorine, and sulfur evaporate in the sintering zone, migrate with the gas, condense on cooler surfaces, and travel back with the feed — enriching cycle after cycle. Consequences include salt-driven expansion behind the hot face, structural spalling in transition zones, and heavy coating build-up at the kiln inlet. Studies of spent transition-zone brick repeatedly show that salt deposition combined with thermal cycling — not clinker attack — is the dominant wear mechanism in that zone. Practical responses, in order: - Control the inputs: raw meal and fuel alkali/chloride/sulfur balance, including alternative fuels. - Manage the process: preheater and smoke-chamber operation to limit build-up. - Choose the lining for the zone: dense, low-permeability alkali-resistant brick at the inlet; spalling-resistant basic brick in transitions; coating-stable basic brick in the sintering zone. - Protect the structure: shell ovality measurement, tyre and roller maintenance, and disciplined heat-up schedules. Anchoring and Installation Notes for Ancillary Equipment The rotating barrel is bricked in rings, and its stability depends on shell roundness, brick geometry, and keying — not on welded anchors. But the static equipment around the kiln uses anchored systems, and most field failures there trace to anchors: - Welded studs and nut assemblies must be qualified for the base steel, installed perpendicular, and hammer-tested one by one. - Folded fiber modules need hot-face coverage of all metal anchor hardware; an exposed anchor becomes a heat path and a corrosion site. - Layered systems (ceramic fiber hot face over calcium silicate backup) must stagger joints so no seam creates a through thermal bridge, and the interface temperature must stay within the backup material's rating — always below its classification temperature, with margin. - Castable and precast nose sections need a supplier-specific dry-out and heat-up curve; steam pressure in an unseasoned castable causes explosive spalling, which is an installation problem, not a material defect. Common Failures and What They Actually Indicate - Structural spalling in transition zones: usually alkali salt deposition plus thermal cycling, not inadequate refractoriness. Check chemistry history before switching to "hotter" brick. - Ring-shaped shell hot spots: often shell ovality or tyre clearance issues converting into brick-ring mechanical failure — measure ovality and kiln axis before relining. - Coating loss in the sintering zone: flame geometry, feed fluctuation, or alternating oxidizing/reducing conditions; the fix is process-side first. - Fiber module shrinkage gaps: high-temperature devitrification and joint opening; plan joint compensation and inspect anchors at every shutdown. - Calcium silicate backup degradation: moisture uptake or interface over-temperature; verify dryness and recheck the layered thermal calculation. Specification Checklist Before You Buy - Define the zone and its role, not just a temperature number. - State the layer position (hot face, intermediate, cold-face backup) for every material on the drawing. - Require continuous-service temperature data, not classification temperature — for ceramic fiber grades this distinction is typically 100–200 °C, with our grades spanning 1000–1430 °C. - Specify backup boards by standard grade, density, thickness, and dryness (ASTM C533 / EN 14306), and confirm interface temperatures by layered heat-up calculation. - For rotating sections, buy brick systems proven under rotation — never soft insulation products as working layers. - Anchor the whole specification with a heat-loss target: agree a shell temperature goal, then work the layer thicknesses backward. For the wider material landscape — fiber, microporous, castables, and their temperature ladder — our 2026 furnace materials guide is the master reference, and our cement kiln thermal protection engineering guide covers the insulation-system side of kiln operation. For a real-world relining sequence in a similar rotating-furnace context, see our petrochemical reformer furnace relining case study. And for insulation practice across the whole plant — preheater, clinker cooler, and beyond — read our calcium silicate insulation guide for the cement industry. FAQ: Q: Can ceramic fiber or calcium silicate board replace the working lining in a rotary kiln? A: No. The rotating barrel imposes charge abrasion, cyclic shell flexing, and salt condensation that soft insulation products cannot survive on the hot face. Ceramic fiber and calcium silicate serve as backup, seal, and heat-storage-reduction layers in the static ancillary equipment — kiln hood, smoke chamber, tertiary air duct, preheater — behind a dense working layer. Q: Which refractories are used in the sintering zone of a cement kiln? A: Basic bricks — magnesia-spinel or dolomite systems — are standard because they take a stable clinker coating that shields them from flame and liquid-phase clinker. Alumina-silica bricks generally cannot hold a stable coating under sintering-zone conditions. Q: Why do transition-zone linings fail even at moderate temperatures? A: Investigations of spent brick consistently show that alkali and salt deposition combined with thermal cycling cause structural and thermal spalling in transition zones — clinker attack is secondary. Chemistry control and spalling-resistant basic brick matter more than raising the rated temperature. Q: What shell temperature should a healthy kiln show? A: Industry studies of large dry-process kilns report roughly 350–400 °C shell surface in the transition and sintering zones when the lining and coating are in good condition, with heat losses in degraded sections reaching 8–15% of heat input. A rising or localized shell temperature is a lining-health alarm, and it should be tracked by infrared scanning. Q: Where should calcium silicate boards be used in a cement plant? A: As rigid cold-face backup behind dense working layers in static equipment — kiln hoods, smoke chambers, ducts, and preheater vessels — and as machinable pack-off material around openings. Specify grades per ASTM C533 or EN 14306, keep the boards dry, and verify that the interface temperature stays well within the board's continuous-service rating. Q: How should backup insulation thickness be decided? A: Work backward from a target shell temperature: build the layered thermal resistance (working layer, interface, backup, external surface), include contact-resistance and hot-spot margins, and iterate with temperature-dependent conductivity data. Never size backup layers from a single classification temperature figure. ### Polycrystalline Fiber Module Supplier: Buyer's Verification Guide URL: https://www.rosetexwool.net/news/polycrystalline-fiber-module-supplier/ 2026-09-18 | Author: Rosetexwool Editorial | Category: industry insight Summary: A practical buyer's guide to selecting a polycrystalline fiber module supplier - fiber purity, anchor systems, ASTM C1786 compliance, and OEM/export capability for furnace linings rated to 1600 °C. Polycrystalline mullite fiber (PCW) modules are the highest-temperature solution in the alumina-silica fiber family, engineered for furnace linings that run continuously at 1500-1600 °C. For buyers comparing a polycrystalline fiber module supplier, the product itself is only half the decision - manufacturing control, anchor engineering, and quality documentation decide whether the lining survives a decade of thermal cycling or fails inside two years. This guide walks through what the fiber actually is, the specifications that matter, and the verification steps that separate a capable supplier from a trading company reselling someone else's blanket. What Are Polycrystalline Mullite Fiber Modules Polycrystalline mullite fiber is produced by a sol-gel process rather than conventional melt-spinning. A high-purity precursor (typically 72-80 % Al2O3 and 20-28 % SiO2) is fiberized, dried, and heat-treated so the final fiber consists of fine mullite (3Al2O3·2SiO2) and alumina crystals with a controlled diameter of roughly 4-6 µm. Because no organic binder is added, the fiber stays crystalline at temperature instead of devitrifying like standard refractory ceramic fiber (RCF). That single difference is why PCW works where RCF tops out: Property | Standard RCF module | Polycrystalline module | Continuous service | 1100-1430 °C | 1500-1600 °C | Binder | Present (burns out) | None | Structure at temp | Devitrifies / shrinks | Stays crystalline | Linear shrinkage @ 1500 °C | Higher | < 1 % | A module is a pre-compressed block of PCW blanket - folded into a concertina or stacked from cut strips - with an integrated anchor system. On site it is fixed to the furnace shell and expands to form a seamless, joint-free hot face. Key Specifications to Request When you ask a polycrystalline fiber module supplier for a quotation, the following numbers should appear on the data sheet - not "high quality" prose. - Alumina content - specify >= 72 % Al2O3 (mullite-grade). Request a mill test certificate per batch. - Classification / continuous temperature - 1600 °C class for most linings; confirm the recommended continuous limit (typically 1500-1600 °C) under your furnace atmosphere. - Module density - folded PCW modules commonly run 160-240 kg/m3. Higher density improves erosion resistance but adds shell load. - Dimensional tolerance - module face 300 x 300 mm is standard; thickness 150-300 mm. Confirm cutting tolerance for your stacking pattern. - Thermal conductivity - expect ~0.25 W/(m·K) at 1000 °C and 0.34-0.45 W/(m·K) at 1200-1400 °C depending on density. - Shot (slag) content - quality PCW carries <= 1 % non-fibrous inclusions. How to Evaluate the Supplier The word "supplier" implies a manufacturing partner, not a catalogue reseller. Use these checks before issuing a purchase order. 1. Fiber purity and traceability A credible PCW module manufacturer controls the sol-gel line in-house. Ask for the Al2O3/SiO2 ratio and a third-party chemical analysis. Inconsistent composition is the fastest route to premature shrinkage. 2. Anchor system engineering Anchors transfer the lining load to the shell. Options include stud-welded, through-wall, and split anchors in stainless steel grades 304, 310, or 316, or ceramic hardware for aggressive atmospheres. The supplier should recommend anchor type from your shell temperature and corrosion profile - and supply shear test data. 3. Standards and certifications Look for ASTM C1786 (standard specification for preformed thermal insulation modules) and EN 1094 references for the fiber product, backed by ISO 9001, CE, and SGS documentation. Certifications are only useful if the supplier can show the valid scope. 4. OEM and export capability For distributors and EPC contractors, confirm private-label and custom-dimension support, seaworthy export packaging, and documented lead times. A supplier exporting to 60+ countries will already have the packing and paperwork discipline your project needs. 5. Quality assurance per batch Request compression-recovery data (modules are shipped compressed 30-50 % and must recover > 90 % after installation) and thermal-cycling test reports. Batch-level QA separates a factory from a trader. Typical Applications Polycrystalline mullite fiber modules are specified wherever the hot face exceeds the RCF limit: - Ceramic and technical-ceramic kilns - Petrochemical ethylene crackers and reformers - Steel reheating and forging furnaces - Glass furnace crowns and regenerator roofs - Incinerators and hazardous-waste linings - Laboratory and aerospace heat-treatment furnaces For a deeper look at the rigid form, see our polycrystalline mullite fiberboard or the ceramic fiber module range, and the full material overview on the ceramic fiber insulation hub. Installation and Anchoring Modules are installed at 4-6 pieces per m2 depending on anchor spacing. Proper stud welding and a running-bond layout minimize joint gaps; a reliable supplier provides layout drawings and, where needed, on-site training. Expansion joints are formed with ceramic fiber paper inserts. Vacuum-lift anchors are preferred on furnace roofs to prevent drop-out. Standards and Compliance - ASTM C1786 - preformed thermal insulation modules - EN 1094 - ceramic fiber insulating products - ISO 9001 / CE / SGS - quality and conformity documentation All Rosetexwool PCW modules are manufactured under an ISO 9001 system, with CE and SGS supporting documents available per order, and are suitable for export to more than 60 countries. Why Specify Rosetexwool With manufacturing heritage since 1982, Rosetexwool supplies polycrystalline mullite fiber modules with verified Al2O3 content, engineered anchor packages, and batch-level quality reports. Our technical team assists with lining design, module layout, and anchor selection so the specification matches the real furnace atmosphere - not a generic datasheet. Request a quotation with your furnace drawing and service temperature, and we will return a module schedule with densities, anchor grades, and lead time. FAQ: Q: What temperature can polycrystalline fiber modules withstand? A: Polycrystalline mullite (PCW) modules are rated for continuous service at 1500-1600 °C, with short-term excursions up to 1700-1800 °C. The exact continuous limit depends on the furnace atmosphere and the module density specified. Q: How do polycrystalline modules differ from standard ceramic fiber modules? A: Standard refractory ceramic fiber (RCF) modules are rated 1100-1430 °C and contain an organic binder that burns out on first heat-up. PCW modules use a sol-gel mullite fiber with no binder, stay crystalline at temperature, and show less than 1 % linear shrinkage at 1500 °C. Q: How do I choose a reliable polycrystalline fiber module supplier? A: Verify four things: (1) in-house sol-gel fiber production with a mill test certificate for Al2O3 content; (2) engineered anchor systems (304/310/316 stainless or ceramic) matched to your shell; (3) ASTM C1786 / EN 1094 references plus ISO 9001, CE, and SGS documentation; (4) batch-level QA reports including compression recovery and thermal-cycling data. Q: Which standards apply to polycrystalline fiber modules? A: Modules are covered by ASTM C1786 (preformed thermal insulation modules) and the fiber product by EN 1094. Quality systems are evidenced through ISO 9001, with CE and SGS supporting documents available per order. Q: Can polycrystalline modules be customized for my furnace? A: Yes. Module dimensions, thickness, density, anchor type, and compression ratio can all be configured from your furnace drawing. Many suppliers also offer private-label and export packaging for distributors and EPC contractors. ### Refractory Ceramic Fiber (RCF) Manufacturer: Grades, Specifications & Supplier Selection URL: https://www.rosetexwool.net/news/refractory-ceramic-fiber-manufacturer/ 2026-09-18 | Author: Rosetexwool Editorial | Category: industry insight Summary: A buyer's guide to selecting a refractory ceramic fiber manufacturer - RCF grades, ASTM C892 specifications, composition certificates, and supplier quality assurance. Refractory ceramic fiber (RCF) is the workhorse alumino-silicate insulation of the high-temperature industry - the material behind most furnace, kiln, and boiler linings running between 1100 °C and 1400 °C. For any buyer shortlisting a refractory ceramic fiber manufacturer, the fiber grade and the supplier's process control matter more than the price on the first quotation. This guide explains what RCF actually is, the grade and specification data you should request, and the verification steps that separate a refractory ceramic fiber manufacturer with its own melt-spinning line from a trader reselling blanket by the roll. What Is Refractory Ceramic Fiber Refractory ceramic fiber is an alumino-silicate wool produced by melting a blend of alumina (Al2O3) and silica (SiO2) - typically 45-55 % Al2O3 - and fiberizing the melt by blowing or spinning. The wool is then processed into blanket, board, paper, rope, cloth, and module forms. RCF earns the "refractory" label because its classification temperature starts at 1260 °C, well past the limit of mineral wool and glass fiber. Within the fiber family it sits between soluble AES fiber (lower temperature, lower bio-persistence) and polycrystalline mullite fiber (higher temperature, higher cost). RCF Grades and Classification Temperatures A credible refractory ceramic fiber manufacturer should offer at least three grades, each with a documented classification temperature: - Standard RCF - classification 1260 °C, recommended continuous service around 1100 °C. The general-purpose grade for most furnace hot faces. - High-purity / high-alumina RCF - classification 1400 °C, continuous service near 1200-1300 °C. Lower impurity (alkali and iron oxide) content for cleaner atmospheres. - Zirconia-containing RCF - classification 1430 °C, continuous service around 1350 °C. Added ZrO2 stabilises the fiber against high-temperature devitrification. Classification temperature is the temperature at which the fiber still meets its linear-shrinkage limit after 24 h; it is not the same as continuous service temperature. Key Specifications to Request When you ask a refractory ceramic fiber supplier for a quotation, these numbers belong on the data sheet - not in marketing prose: - Chemical composition - Al2O3 and SiO2 content, plus impurity limits (Fe2O3, alkali oxides, CaO + MgO). Request a mill test certificate per batch. - Classification / continuous temperature - confirm the grade and the recommended continuous limit under your furnace atmosphere. - Density - blanket commonly 64-160 kg/m3; board 280-400 kg/m3 depending on rigidity and application. - Fiber diameter and shot (slag) content - quality RCF carries low non-fibrous shot, typically below 15-20 % for blanket, improving handleability and thermal performance. - Thermal conductivity - expect roughly 0.08-0.12 W/(m·K) at 400 °C and 0.18-0.25 W/(m·K) at 800-1000 °C depending on density. - Loss on ignition (LOI) - organic binder content, verified so the lining does not shrink abnormally on first heat-up. For product detail on the most common forms, see our ceramic fiber blanket, ceramic fiber board, and ceramic fiber module ranges, with the full material overview on the ceramic fiber insulation hub. How to Evaluate the Manufacturer The word "manufacturer" implies a production partner, not a roll reseller. Use these checks before issuing a purchase order. 1. In-house melt and spin control A capable refractory ceramic fiber manufacturer runs its own melting and fiberizing line. That vertical control is what lets the supplier hold Al2O3 content and shot level batch after batch - and document it. 2. Grade range and customization Beyond standard blanket, confirm the supplier can deliver board, paper, rope, cloth, module, and custom shapes, and can tune density and thickness to your lining design rather than only stock sizes. 3. Standards and certifications Look for ASTM C892 (standard specification for RCF blanket) and EN 1094 references for ceramic fiber products, backed by ISO 9001, CE, and SGS documentation. Certifications are only useful if the supplier can show the valid scope and the test reports behind them. 4. Export and project capability For distributors and EPC contractors, confirm seaworthy export packaging, private-label option, and documented lead times. A manufacturer exporting to 60+ countries already carries the packing and paperwork discipline your project needs. 5. Batch-level quality assurance Request thermal-cycling and linear-shrinkage test reports, plus compression-recovery data for module products. Batch-level QA is the difference between a factory and a trader. Typical Applications Refractory ceramic fiber is specified wherever the hot face sits between roughly 1100 °C and 1400 °C: - Steel and foundry furnace linings and covers - Ceramic and technical-ceramic kilns - Petrochemical reformers, crackers, and heaters - Heat-treatment and annealing furnaces - Boiler and duct insulation - Power-plant and incinerator linings Standards and Compliance - ASTM C892 - RCF blanket specification - EN 1094 - ceramic fiber insulating products - ISO 9001 / CE / SGS - quality and conformity documentation All Rosetexwool RCF products are manufactured under an ISO 9001 system, with CE and SGS supporting documents available per order, and are suitable for export to more than 60 countries. Why Specify Rosetexwool With manufacturing heritage since 1982, Rosetexwool supplies refractory ceramic fiber in every standard form - blanket, board, paper, rope, cloth, and module - with verified composition, documented grade temperatures, and batch-level quality reports. Our technical team assists with lining design and grade selection so the specification matches the real furnace atmosphere, not a generic datasheet. Request a quotation with your service temperature and form requirement, and we will return a grade schedule with densities, impurity limits, and lead time. FAQ: Q: What is refractory ceramic fiber (RCF)? A: Refractory ceramic fiber is an alumino-silicate insulation wool (roughly 45-55 % Al2O3 plus SiO2) made by melting and fiberizing the blend, then forming it into blanket, board, paper, and module. Its classification temperature starts at 1260 °C, placing it above mineral wool and glass fiber for high-temperature furnace linings. Q: What temperature can refractory ceramic fiber withstand? A: Standard RCF is classified 1260 °C with recommended continuous service around 1100 °C. High-alumina grades reach 1400 °C classification (about 1200-1300 °C continuous), and zirconia-containing grades reach 1430 °C classification (about 1350 °C continuous). Q: How do I choose a reliable refractory ceramic fiber manufacturer? A: Verify five things: (1) in-house melting and fiberizing line with batch mill-test certificates for Al2O3 content; (2) a full grade range (standard, high-alumina, zirconia) and form flexibility; (3) ASTM C892 / EN 1094 references plus ISO 9001, CE, and SGS documentation; (4) export packaging and lead-time discipline; (5) batch-level QA including linear-shrinkage and thermal-cycling reports. Q: What certifications should an RCF manufacturer hold? A: The product is referenced against ASTM C892 and EN 1094; the quality system is evidenced through ISO 9001, with CE and SGS supporting documents available per order. Ask for the valid certificate scope and the test reports behind each claim. Q: Which RCF grades are available? A: Three main grades: standard RCF (1260 °C classification, ~1100 °C continuous), high-purity / high-alumina RCF (1400 °C classification, ~1200-1300 °C continuous), and zirconia-containing RCF (1430 °C classification, ~1350 °C continuous). Each is selected from the furnace atmosphere and service temperature. ### Rosetexwool at LDES 2026: Insulation for Long-Duration Energy Storage URL: https://www.rosetexwool.net/news/rosewool-at-ldes-2026-xian/ 2026-09-16 | Author: Rosetexwool Editorial | Category: company news Summary: Rosetexwool exhibits rock wool, calcium silicate, ceramic fiber and aerogel insulation at LDES 2026 in Xi'an, 16-18 September, linking material choice to molten salt heat storage and battery safety. Xi'an, 16 September 2026 — Rosetexwool Insulation Refractory Co., Ltd. is exhibiting this week at LDES 2026, the 4th Long-Duration Energy Storage Conference and Exhibition, held from 16 to 18 September 2026 at the Xi'an International Convention and Exhibition Center. At booth B3, the company presents its rock wool, calcium silicate, ceramic fiber and nano-aerogel insulation lines to project developers, EPC contractors and design institutes working on long-duration energy storage. About LDES 2026 LDES 2026 runs under the theme "Reshaping the energy storage landscape, strengthening the energy foundation". The event is organised by a leading Chinese long-duration energy storage industry platform together with state-owned power engineering partners, and brings together more than 1,200 delegates, 600 organisations, 80+ exhibitors, 3,000+ professional visitors and 70+ speakers. The conference covers the full range of long-duration storage routes across three parallel tracks: - Long-duration physical storage — compressed air, liquid air, carbon dioxide, heat pump and gravity storage - Long-duration electrochemical storage — flow batteries and long-duration lithium systems - Thermal energy storage — molten salt, solid and water heat storage, phase change and seasonal heat storage As the market moves from today's mainstream 4-hour systems toward longer durations, thermal energy storage and hybrid physical storage are scaling quickly — and every one of these routes is, at its core, an insulation problem. What we are presenting at booth B3 The booth showcases the four material families Rosetexwool supplies to energy storage and industrial customers in more than 60 countries: - Rock wool boards and blankets — non-combustible mineral wool insulation for thermal energy storage vessels, plant rooms and battery storage containers - Calcium silicate boards — rigid, high-strength insulation for molten salt tank bases and hot surfaces that also carry mechanical load - Ceramic fiber blankets, papers and modules — refractory insulation for high-temperature equipment above the range of conventional mineral wool - Nano insulation boards, aerogel blankets and aerogel coatings — thin-build insulation where installation space around tanks and pipework is limited Visitors can review datasheets, certification documents and sample products at the booth, and discuss project-specific requirements with the export team. Insulation across long-duration storage routes Molten salt thermal energy storage. Two-tank molten salt systems operate at up to about 565 °C. Tank side walls, foundations and interconnecting pipework need insulation that holds shell temperatures down, limits standby heat loss and stays dimensionally stable through thousands of daily charge-discharge cycles. Combining calcium silicate at load-bearing locations with rock wool boards and blankets across large flat surfaces is a proven specification pattern. The same layered logic applies to industrial applications across power generation. Compressed air and heat storage. Above-ground thermal stores, heat exchangers and pressure vessels in advanced compressed air systems run at similar or higher temperatures, where ceramic fiber products and aerogel blankets provide the service temperature and thin-build performance conventional materials cannot reach. Battery energy storage safety. For electrochemical storage containers, the insulation role shifts from heat retention to fire protection. Non-combustible rock wool with an A1 fire rating is used in container walls, ceilings and fire barriers between battery bays, slowing fire spread and protecting adjacent equipment. For a deeper comparison of reaction-to-fire classes, see our guide to A1 vs A2 vs B fire ratings. Selecting insulation for thermal energy storage Material selection for storage applications follows the same engineering order as any high-temperature project: service temperature first, then thermal conductivity at the real operating temperature rather than at room temperature, then dimensional stability across thermal cycles, moisture behaviour and mechanical strength. Our reference on insulation wool temperature ratings sets out the first filter in detail. As a rough map, rock wool serves to about 650 °C, calcium silicate to about 1,000 °C, ceramic fiber products up to 1,430 °C, and aerogel blankets cover roughly 650 °C with a fraction of the thickness. Continuing the conversation The exhibition runs until 18 September. The Rosetexwool export team welcomes visitors at booth B3 throughout the conference. Customers who cannot attend this week can reach the team through our product pages or request quotations for custom-cut insulation packages for molten salt, compressed air and battery storage projects. With in-house production of rock wool, calcium silicate, ceramic fiber and nano insulation products, Rosetexwool has supported thermal insulation projects since 1982 and exports to more than 60 countries under ISO 9001, CE and SGS certification. The company also supplies the building envelope market with the same non-combustible product families. Related Reading - A1 vs A2 vs B fire ratings explained - What temperature can rock wool withstand - Calcium silicate board density, thickness and thermal conductivity spec guide - Non-combustible insulation systems with A1 fire rating FAQ: Q: When and where is LDES 2026 held? A: LDES 2026, the 4th Long-Duration Energy Storage Conference and Exhibition, runs from 16 to 18 September 2026 at the Xi'an International Convention and Exhibition Center. The event brings together delegates from grid operators, power generators, project investors, design institutes, EPC contractors and equipment suppliers across the long-duration storage industry. Q: What is Rosetexwool presenting at the exhibition? A: The booth presents four insulation families used in energy storage and industrial projects: rock wool boards and blankets, calcium silicate boards, ceramic fiber blankets, papers and modules, and nano insulation products including aerogel blankets and coatings. Visitors can review datasheets, certification documents and samples, and discuss project-specific requirements with the export team. Q: Which insulation suits molten salt thermal energy storage tanks? A: Two-tank molten salt systems operate at up to about 565 °C, so the first filter is service temperature. Calcium silicate is typically used at load-bearing locations such as tank foundations because it combines high-temperature capability with compressive strength, while rock wool boards and blankets cover large side-wall and roof areas. Thin-build aerogel blankets are used where space around pipework is limited. Q: Is rock wool suitable for battery energy storage containers? A: Yes, where the requirement is fire protection rather than heat retention. Non-combustible rock wool with an A1 reaction-to-fire classification is used in container walls, ceilings and fire barriers between battery bays. The complete assembly has to be assessed, because fire performance depends on the system, fixings and junctions as well as the insulation itself. Q: Can Rosetexwool supply custom insulation packages for energy storage projects? A: Yes. Rosetexwool produces rock wool, calcium silicate, ceramic fiber and nano insulation products in-house and supports cut-to-size boards, custom shapes and complete insulation packages for molten salt, compressed air and battery storage projects. The company has supplied thermal insulation since 1982 and exports to more than 60 countries under ISO 9001, CE and SGS certification. ### A1 vs A2 vs B Fire Rating: Which Euroclass Should You Specify? URL: https://www.rosetexwool.net/news/a1-a2-b-fire-rating-comparison/ 2026-09-15 | Author: Rosetexwool Editorial | Category: industry insight Summary: A1, A2 and B answer different specification questions. This guide compares test routes, the limited-combustibility boundary, façade rules and a worked selector. Why Compare A1, A2 and B (Not Just “A1 Is Best”) A1, A2 and B sit next to one another on the Euroclass scale, yet they answer different specification questions. This guide is a practical A1 vs A2 vs B fire rating comparison for insulation specifiers. A1 represents the non-combustible family. A2 covers products with limited combustibility. B is a combustible class with limited fire contribution. Treating A1 A2 B as a single quality ladder — and assuming the highest class is always the right answer — leads to over-specified, expensive systems in some projects and under-specified systems in others. The real decision is not which letter wins. It is whether the material, the complete system and the building regulation route can all clear the same fire-safety bar. This guide compares A1, A2 and B at that decision level: what each class means, how the classification routes differ, where each is normally required, what it costs in thickness and thermal design, and how to choose without confusing product reaction with system approval. Use this guidance for initial selection only. Reaction-to-fire classification, national regulations and system approvals change. This article does not replace the current UK Building Regulations, Approved Documents, applicable EN/CEN standards, EU national rules, fire-engineered design, or advice from building control and a competent fire-safety professional. The Test Stack Behind Each Class Euroclass A1, A2 and B are assigned through EN 13501-1, which organises reaction-to-fire tests rather than measuring one single property. The most useful way to compare the three classes is by the classification route — what a product must demonstrate — which is why the A1 A2 B comparison below is framed as a decision table rather than a list of fixed thresholds. For the full Euroclass system including the A1–F scale and the s1–s3/d0–d2 subscripts, see the Euroclass fire classification guide. Decision question | A1 | A2 | B | Is the product in the non-combustible family? | Yes, when classification requirements are met | Limited-combustibility family; confirm the route | No | Does SBI normally form part of the route? | Not as the defining route | Yes | Yes | Is calorific-value / non-combustibility evidence central? | Yes | Usually relevant to the limited-combustibility route | Not the defining route | Can a core-only result approve a façade system? | No | No | No | Must s/d and system tests still be checked? | Yes | Yes | Yes | For A1, classification normally relies on non-combustibility and gross heat of combustion. EN ISO 1182 assesses non-combustibility, while EN ISO 1716 measures gross calorific value (PCS). SBI, from EN 13823, is not the defining A1 route. For A2, the route is often described as a combination of near-non-combustible or calorific-value evidence together with SBI performance. Public technical summaries commonly associate A2 with a PCS boundary around 3.0 MJ/kg and SBI values such as FIGRA ≤120 W/s, but these figures must be confirmed against the version-specific classification rules and the product’s Declaration of Performance (DoP). The same caution applies to A1’s 2.0 MJ/kg boundary: it is a useful industry reference, not a substitute for the applicable standard and product construction. Class B typically follows the SBI route and includes EN ISO 11925-2 small-flame considerations. B is therefore not defined by having a uniquely different FIGRA value from A2. In many published classification structures, A2 and B can occupy the same SBI performance band. Their distinction lies in whether the product meets the near-non-combustible or limited-combustibility path — not in a simple “A2 has SBI, B does not” rule. Do not write a laboratory report when the project needs a specification decision. Precise thresholds depend on standard version, homogeneous versus non-homogeneous construction, whole-product versus minor-component limits, and the declared product form. If a number matters to a compliance claim, take it from the DoP and the applicable standard, not from a generic comparison table. A1 vs A2: The Combustion-Heat Line The practical boundary between A1 and A2 is often discussed as a combustion-heat line: A1-like performance at very low calorific value, with A2 permitting a more limited combustible contribution. This is a reasonable shorthand, but it should never be presented as a single universal number that automatically decides every product’s class. A1’s strength is regulatory certainty. Inorganic fibers, mineral-based boards, ceramic-type materials and calcium silicate products can sit in the A1 candidate family. That does not mean every inorganic material is automatically A1. Binders, facings, coatings, composite cores, thickness, orientation and test construction can all affect classification. The non-combustible insulation systems guide covers the A1 route in more detail. A class A2 fire rating is therefore not a weaker A1; it is a separate classification route. A2 exists because real building products are rarely perfectly homogeneous and entirely free of organic components. Thin composite panels, faced mineral wool systems, boards with higher binder content and certain clad constructions may achieve a limited-combustibility position where a pure A1 route is harder to demonstrate. A2 should be described as near-non-combustible or limited-combustibility performance with additional classification conditions — not as “A1 on a budget.” The correct writing position is conditional: Where the applicable EN 13501-1 classification rules require gross heat of combustion limits, the relevant PCS values must be taken from the declared product construction and the standard version stated on the DoP. That phrasing protects both accuracy and the reader. It also prevents a common error: converting an A1 vs A2 comparison into a marketing absolute about “≤2.0 MJ/kg for A1, ≤3.0 MJ/kg for A2” when the actual rules can distinguish between the whole product and internal or external minor components. A2 vs B: Combustible, but How Limited? A2 and B are sometimes presented as if the only difference is a more relaxed SBI score. The research does not support that simplification. Both classes may use SBI-based evidence, and both can appear with the same FIGRA-style performance under typical classification summaries. The more useful distinction is how far the product moves away from the non-combustible or limited-combustibility boundary. - A2 is a limited-combustibility class. It is attractive where the specification requires a strong reaction-to-fire position but the product cannot, or need not, be classified as fully non-combustible. - B is a combustible class with limited fire contribution. Class B insulation — often organic foam insulation — targets B or lower classes because it can deliver strong thermal efficiency, but its use is application- and specification-dependent. - Similar SBI does not mean A2 and B are interchangeable. Jurisdiction, building element, complete-system approval and the precise Euroclass (including s and d subscripts) can make one suitable and the other unacceptable. A2 does not automatically solve a high-rise façade problem. In the UK, external wall safety is assessed at system level: insulation core, cladding or render, cavities, fire barriers, fixings, junctions, window reveals and the relevant large-scale test or engineered assessment. A material labelled A2-s1,d0 may be essential to a compliant design, but the label alone does not “approve” the wall. B is not automatically unsafe either. B-s1,d0 products may be appropriate for many applications where the complete specification and local rules permit them. The error is to select B for a high-risk, exposed or regulated element without checking whether the jurisdiction requires A1, A2 or a tested complete system. Smoke and Droplet Classes in the A1/A2/B Context A Euroclass is more than its first letter. The full notation can include s for smoke production and d for flaming droplets or particles: - s1 indicates the best smoke-performance category in the standard’s scale; higher numbers indicate more smoke. - d0 indicates no, or very limited, flaming droplets; d1 and d2 indicate progressively greater droplet behaviour. - A full class might read B-s1,d0, not simply “Class B.” A1 products are non-combustible in the classification context, so smoke and droplet sub-levels are not the same decision as they are for combustible classes. For A2 and class B insulation, however, ignoring the subscripts is a material-selection mistake. Material-level fire behaviour for a common insulation family is covered separately in is glass wool fireproof. A2-s1,d0 and B-s2,d1 are not equivalent just because their main letters differ by one step; the smoke and droplet behaviour may materially change acceptability in internal linings, escape routes and sensitive enclosures. Rule of thumb: choose the complete Euroclass first, then check whether the system, location and regulation require a particular s/d pair. A project that accepts “A2” in theory may still reject a product with the wrong smoke or droplet rating in practice. When Each Class Is Required The following table is a decision framework, not a promise that a class letter automatically grants permission. Height thresholds, building types and regulation versions vary by jurisdiction and project date. In England, for example, relevant amendments to the building regulations introduced an 18-metre reference for combustible materials in certain external walls of relevant buildings; the exact obligation still depends on the building category, construction or major-refurbishment timing, and the current regulatory wording. Application or jurisdiction | What commonly drives the choice | Minimum class as a starting point | What must be confirmed | High-risk external walls, relevant residential or similar buildings (England) | Ban/restriction on combustible materials in certain external walls | Often A1 or a non-combustible route | Building type, height, regulation version, system route, building control | Tall façades and rainscreen systems | Complete-system performance, cavity barriers, fire stopping | A1 or A2 insulation may be required by specification | BS 8414/BR 135 or relevant system evidence; full design details | Mid-rise or A2-specified façades | Strong reaction-to-fire position without a universal A1 requirement | A2 may be suitable | Jurisdiction, building control, complete system approval | Internal linings and protected escape routes | Main class plus s/d, surface and lining rules | A2 or B may be suitable | Local fire strategy, lining rules, smoke/droplet class | Low-rise, non-critical elements | Thermal performance and cost can carry more weight | B may be viable | National rules, product DoP, fire-engineered design if used | Nuclear, cleanroom and zero-combustible-content environments | Strict non-combustible or low-fire-load demand | Typically A1 | Project specification and specialist fire safety design | Height needs a warning label. The well-known 18-metre threshold in England is specific to certain buildings and regulatory conditions. An 11-metre figure appears in some remediation, funding and risk-assessment discussions, but should not be treated as a direct replacement for the 18-metre construction rule. A 30-metre threshold should not be stated as a general UK legal rule unless original legislation or local building control provides project-specific support. For every high-rise or external-wall application, ask: - Which regulation and version applies to this project? - Does the rule apply to the whole system or the insulation core? - What does the current DoP declare for this exact product and thickness? - Is there large-scale system evidence or a recognised assessment route? - Has a competent fire-safety professional reviewed the complete construction? If the answer to any of these is unknown, stop short of declaring the product “high-rise approved.” The Trade-off Reality: Cost, Thickness, Thermal and Design Freedom If A1 is the most conservative fire answer, why not specify it everywhere? Because insulation selection is a multi-objective decision: fire risk × regulation × thermal performance × thickness × weight × installation × budget × design intent. Factor | A1 (typical rock wool / mineral/inorganic route) | A2 (limited-combustibility route) | B (organic-foam route) | Fire position | Strongest of the three | Strong, near-non-combustible | Combustible but limited | Typical thickness for target U-value | Often greater | Can be more design-flexible | Often thinner for comparable thermal performance | Weight and handling | Often denser and heavier | System-dependent | Light, easy to handle in many forms | Thermal design | Excellent in the right system, but not automatically superior per mm | Good design flexibility | Frequently strong thermal performance | Regulatory constraint | May be mandated in high-risk elements | May satisfy non-A1 specifications | Most application-limited | Cost drivers | Material, thickness, installation weight | System complexity and certification | Thermal value, but offset by restrictions | A1 mineral wool insulation may be thicker and heavier than class B insulation using an organic foam core for a comparable target U-value. That can increase structural considerations, fixings, labour and overall build depth. A2 composite or faced systems can reduce some of those constraints while retaining a limited-combustibility position. B-class organic foam can look highly efficient on paper because of its thermal properties, but its fire restrictions can eliminate it from exactly the façade or escape-route applications where thickness matters most. The selector below turns this into an actionable sequence: establish the fire constraint first, then optimise thermal and cost within the allowed classes. A1/A2/B Across Standards No cross-standard mapping should be presented as an automatic legal equivalence. EN 13501-1, UK building regulations, BS 476, ASTM E84 and China’s GB 8624 address different test concepts, product forms and jurisdictions. Use the table below only as a starting orientation. EN 13501-1 position | UK context | US context (ASTM E84) | China context | A1 | Often aligned with non-combustible thinking; UK routes depend on application | Surface-burning class context, not a direct conversion | GB 8624 uses its own classification framework; seek version-specific mapping | A2 | Limited-combustibility route; UK acceptance depends on the complete system | Approximate performance context only | GB 8624 mapping requires product-specific comparison | B-s1,d0 | May be suitable in some lining/product applications | Not a one-for-one conversion | GB 8624 mapping requires product-specific comparison | In the UK, Class 0 is a well-known performance description derived from BS 476-6 and BS 476-7, commonly associated with wall and ceiling linings. It is not a direct substitute for A1, nor does a Euroclass certificate automatically become Class 0. A valid comparison needs the test report, standard version and the applicable route for the intended building element. In the US, ASTM E84 measures surface burning characteristics, commonly reported through a flame spread index and smoke-developed index. It is not a mechanism for translating FIGRA, PCS or an EN 13501-1 letter class into a US legal class without a tested, jurisdiction-specific comparison. China’s GB 8624 classification is included here only for orientation. It should be described as a separate national system with its own version-specific mapping — not as a line-by-line equivalent of EN 13501-1. Worked Decision Selector Use this selector in order. Move to the next question only after the previous constraint is satisfied. Step | Question | If yes | If no | 1 | Does the jurisdiction or fire strategy require A1 / non-combustible materials for this element? | Restrict the shortlist to A1-capable systems | Continue to step 2 | 2 | Is the element a high-rise or high-risk external wall, or does it require a tested complete system? | Prioritise A1/A2 and obtain system-level evidence | Continue to step 3 | 3 | Can A2’s limited-combustibility route satisfy the specification and DoP? | A2 may be the optimum balance | Continue to step 4 | 4 | Is the application low-risk or internal, with allowed B use and suitable s/d performance? | Assess B with full Euroclass and regulation check | Re-review A1/A2 | 5 | Does the complete system — not just insulation core — meet the fire strategy? | Proceed to thermal and cost optimisation | Return to material/system selection | Example 1 — tall residential façade: A1 is usually the starting point because of regulatory and fire-strategy requirements. Even then, the full cladding system, cavity barriers and fixings must be assessed. A2 cannot be assumed simply because its letter is close to A1. Example 2 — mid-rise ETICS or rainscreen: A2 may provide the optimum balance between fire position and design flexibility. Confirm the exact product, thickness, system route and building control requirements before specification. Example 3 — low-rise internal element: B-s1,d0 may be compliant and thermally efficient. Check the lining rules, smoke/droplet class, occupancy and escape-route implications rather than assuming B is banned or universally acceptable. The selector is intentionally conservative. Its purpose is to prevent a familiar specification error: choosing a product class before choosing the system and regulatory route. Common Mistakes When Choosing the Class “A1 is always mandatory.” No. A1 is mandatory where the jurisdiction, building type or fire strategy says so. Many buildings and internal applications can be designed with A2 or B where the rules allow. The mistake is not using A1 everywhere; it is failing to identify where A1 is actually required. “Class 0 equals A1.” No. They arise from different test cultures and product contexts. Class 0 may represent strong UK lining performance, but it is not a one-to-one Euroclass A1 equivalent. “A2 is the same as A1 on a façade.” No. The classes are not interchangeable, and neither class alone proves complete-wall compliance. The system matters as much as the insulation. “B is unsafe.” No. B-s1,d0 is used in compliant applications every day. The correct question is whether B is permitted for the specific element, location, smoke/droplet condition and jurisdiction — not whether the letter “B” sounds acceptable in isolation. “A1 insulation makes the building fireproof.” No. A1 describes reaction to fire under a defined classification. Fire resistance, fire spread, compartmentation, cavity design and installation quality remain separate considerations. “A2 and B differ because B has a much higher FIGRA limit.” Unsupported. Classification summaries often place A2 and B in the same SBI band. Their difference is better understood through the limited-combustibility route and overall classification conditions. Our Material Scope Our insulation portfolio focuses on inorganic, high-temperature and mineral-based material families. The following are candidate routes for A1 or A2 performance, depending on the exact product, thickness, facing, binder system, test construction and DoP: - Rock wool / mineral wool insulation — commonly used where non-combustible or limited-combustibility performance is required. - Glass wool insulation — suitable for selected thermal and acoustic applications, with classification confirmed by product data. - Ceramic fiber insulation — used in high-temperature industrial and thermal-processing contexts. - Calcium silicate insulation — an inorganic board and structural-insulation family with strong fire-performance potential. Some faced boards, composites and systems within these families may be classified A2 rather than A1. The correct class must always be taken from the current DoP for the exact product and construction, not inferred from the generic material name. Honest boundary: organic-foam insulation in the B-class range, such as PIR- or phenolic-core products, is not part of our current insulation portfolio. Where a specification requires an A1 or A2 route, our mineral-fiber, ceramic-fiber and inorganic-board families can be assessed. Where a B-class organic-foam solution is preferred for thermal efficiency, the choice must be justified against the complete system and the applicable fire-safety design — not selected on thermal performance alone. Explore our rock wool insulation, glass wool insulation, ceramic fiber insulation and calcium silicate insulation families to find product data and declarations matched to your specification. Related Reading - Euroclass Fire Classification for Insulation — the full A1–F system, smoke/droplet subscripts and risk context. - Non-Combustible Insulation Systems: The A1 Fire Rating — what A1 means, how it is demonstrated and where it is required. - Is Glass Wool Fireproof? — material-level behaviour and the limits of single-material fire claims. FAQ: Q: Is A1 better than A2? A: A1 sits in the non-combustible family and offers the strongest reaction-to-fire position, but "better" depends on the application. A2 is a limited-combustibility class that can suit systems where A1 would be unnecessarily restrictive. The right choice follows the building type, height, element and jurisdiction — not the class letter alone. Q: Can A2 be used on high-rise facades? A: Not on the basis of the insulation label alone. In the UK, external wall performance depends on the complete system, fire barriers, fixings, junctions and relevant test or assessment routes. A2-s1,d0 insulation may be suitable in some designs, but current building control and a competent fire-safety professional must confirm compliance for the specific project. Q: What is the difference between A2 and B? A: A2 and B may share SBI-based fire-performance characteristics, but their classification routes differ. A2 sits closer to the non-combustible or limited-combustibility boundary, while B is a combustible class with limited fire contribution. They are not automatically interchangeable, even where SBI figures appear similar. Q: Is Class B insulation safe? A: B is not a synonym for unsafe. B-s1,d0 products are used in many compliant applications where the specification, location and building rules allow them. Safety depends on the full Euroclass, the product form, the construction element and the applicable regulation — never on the main class letter in isolation. Q: Does A1 mean fireproof? A: No. A1 describes reaction to fire of a product under a defined classification system; it does not mean the material is immune to fire or that a complete building element is automatically safe. Fire resistance, system behaviour and installation design must be assessed separately. Q: Does Class 0 equal A1? A: No. Class 0 is a UK route based on BS 476 tests, while A1 comes from the EN 13501-1 reaction-to-fire system. The two frameworks address different test concepts, so they should not be treated as a direct one-to-one equivalence without a valid, version-specific comparison. ### Ceramic Fiber Bulk, Blanket and Board: One Fibre, Three Structures URL: https://www.rosetexwool.net/news/ceramic-fiber-blanket-bulk-board-forms/ 2026-09-14 | Author: Rosetexwool Editorial | Category: industry insight Summary: Ceramic fiber bulk, blanket and board are one fibre in three structures. How each is made, why density beats form at high temperature, and how the three work together. Quick answer: Ceramic fiber bulk, ceramic fiber blanket and ceramic fiber board are the same alumino-silicate fibre in three structural states. Bulk is the loose, unformed fibre that comes off the fibre line, and everything else is made from it. Blanket is bulk that has been needled into a flexible, binder-free mat at roughly 96–160 kg/m³. Board is bulk that has been slurried, dosed with an inorganic binder and vacuum formed into a rigid panel at 220–400 kg/m³. Chemistry and temperature class are frequently identical across the three. What actually changes is density, stiffness, thermal shock behaviour, and the way each form fails. Most buyers meet these products as a choice — which form do I order? That comparison is worth doing, and it is covered properly elsewhere. This article takes the question underneath it: the three forms are not competing products so much as three points on one manufacturing chain, and understanding where the chain forks explains behaviour that a specification table cannot. Once you can see bulk as the feedstock, blanket as the mechanically bonded branch and board as the binder-bonded branch, the rest of the specification — why a ceramic fiber board cracks where a blanket does not, why low density stops being an advantage above 600 °C, why the best furnace lining usually uses all three — follows directly. One Fibre, Three Structures Every ceramic fiber product starts as the same thing: molten alumino-silicate, melted in an electric arc or resistance furnace and then attenuated into fibre. The chemistry is set at that point. A 1260 °C grade is a 1260 °C grade whether it ends up as loose fill, a needled mat or a rigid panel. What differs is everything that happens afterwards. The fibre leaving the line — bulk — is a low-density mass of randomly oriented filaments with no strength of its own. To become a product, that mass has to be given a structure, and there are only two ways to do it. The first is mechanical: drive barbed needles through the fibre mat repeatedly so the filaments physically tangle and interlock. That produces ceramic fiber blanket. No adhesive is added; the strength is purely mechanical and the mat stays flexible and compressible. The second is chemical: disperse the fibre in water, add an inorganic binder, then pull the water out through a screen under vacuum so the fibre and binder deposit as a shaped, coherent solid. That produces ceramic fiber board — and, by the same route, vacuum-formed special shapes. The fork matters because the two routes buy strength with different currency. Needling buys it with fibre entanglement and keeps the structure compliant. Vacuum forming buys it with binder and makes the structure rigid. Every performance difference that follows — thermal shock tolerance, machinability, behaviour on first firing, erosion resistance — traces back to that single choice. From Melt to Fibre: Where the Three Forms Diverge The fibre itself is made by one of two attenuation methods, and the choice sets the raw material character before any forming happens. In the spun route, the melt stream falls onto a spinning wheel or is flung off a rotor, drawing filaments of roughly 3–4.5 µm diameter that are relatively long and tangled. In the blown route, a high-velocity gas jet attenuates the stream into shorter, finer filaments of about 2–3 µm with lower shot content. Those small differences propagate. Spun fibre is tougher and holds together under mechanical stress, which makes it the natural feedstock for ceramic fiber blanket, for textile products and for folded modules. Blown fibre is finer and packs more uniformly, which is why it is preferred wherever the material will later be vacuum formed — board, shapes, and lightweight fill. Then the two forming branches: Needling. Layers of spun fibre are laid into a mat and needled from both sides. The barbed needles push fibre through the thickness of the mat, creating a three-dimensional mechanical bond through the full section rather than a surface skin. Density is controlled by how many layers go in and how aggressively the mat is needled and calendered — typically 96–160 kg/m³ for a ceramic fiber blanket, with 128 kg/m³ the common industrial figure. Nothing is added. A finished blanket is essentially 100% fibre. Vacuum forming. Bulk fibre is dispersed into a water slurry with a binder — usually an inorganic system based on silica or alumina sol, sometimes with a small organic fraction for green strength. A shaped screen is immersed, vacuum draws the water out, and the fibre and binder deposit on the screen in the shape of the screen. The wet form is then dried, and often pressed or calendered to a final density. Board normally lands at 220–400 kg/m³, roughly two to three times a blanket. The binder is the important part. It is what lets a ceramic fiber board be cut, drilled, stood on edge and anchored without tearing. It is also what makes the board a different material at first heat: the binder has to cure and stabilise in service, and during the first firing a board will normally lose mass and, if heated too quickly, can crack or spall as binder residues and moisture leave the section. Bulk: The Unformed Feedstock Ceramic fiber bulk is fibre with no structure imposed on it — loose, white, 60–100 kg/m³, and with no tensile or compressive strength worth naming. It is the cheapest of the three by a wide margin and the least capable on its own. Its jobs are correspondingly specific. Bulk is used to fill irregular cavities that no flat product can reach, to pack around penetrations and burner blocks, to stuff expansion joints, to be blown into voids behind a lining, and to be mixed into refractory castables and coatings as a lightweight aggregate. It is also the feedstock for vacuum-formed ceramic fiber board and shapes, and the raw material for many textile products, which is why a supplier's bulk grade and its board grade usually share a chemistry. The honest limitations: bulk settles. Under vibration, thermal cycling, or simply its own weight over time, loose fibre consolidates downward and leaves a void at the top of a cavity, which shows up as a hot spot on the shell. It has no erosion resistance, so any gas velocity above a few metres per second will move it. And it cannot be counted on for a designed thickness, because a filled cavity rarely has a uniform packing density. Where a lining has to keep a specified thermal resistance for years, bulk is a supplement, not the working layer. Blanket: Needled and Binder-Free A ceramic fiber blanket is bulk that has been given a mechanical structure and nothing else. The needling process tangles filaments through the thickness of the mat, so the blanket develops enough handling strength to be cut, wrapped around a pipe, draped over a crown, and impaled on anchors without falling apart — while remaining soft enough to compress by hand. The binder-free construction is the reason blanket behaves the way it does. With no binder to burn out, there is no first-firing mass loss, no smoke and no cure schedule to respect. More importantly, the compliant structure absorbs strain: when a furnace cycles from ambient to 1000 °C and back, the blanket compresses and recovers rather than cracking. That is why a ceramic fiber blanket is the default answer wherever thermal shock is the governing risk, and why it is the standard choice for the back-up layers behind a hotter hot-face material. The trade is mechanical. Tensile strength is low — on the order of 0.04 MPa — so a ceramic fiber blanket tears at anchor points and at any attachment that carries load. It erodes under high gas velocity, which is the usual reason a blanket hot face fails in a furnace with a strong draft. And because it is compressible, it loses thickness under sustained mechanical load, so a ceramic fiber blanket used where something bears against it will deliver less insulation than the nominal thickness suggests. Standard thicknesses run 6–50 mm and the product is supplied in rolls, which is a large part of why it is economical: a two-layer blanket installation goes on fast, and the labour saving usually outweighs the material cost difference against board. Board: Vacuum-Formed Rigidity A ceramic fiber board is the same fibre with a binder and a shaping process. The vacuum-forming route produces a flat, self-supporting panel with a smooth face, a consistent thickness, and enough rigidity to be handled as a piece of material rather than a layer of insulation. That rigidity changes the application set completely. Ceramic fiber board is the form you specify when the insulation has to resist gas velocity, take a mechanical fix, hold a flat surface against a casing, or be machined to a profile. It can be cut, drilled, routed and sanded, which is why it turns up as baffles, door linings, hot-face panels, and backup board behind dense refractory. It is also the form used when a lining has to be self-supporting between anchors rather than impaled on them. The costs are real. Board is denser, so it stores more heat per unit volume in a cycling furnace — thicker board means longer heat-up and more energy held in the lining. It is rigid, so it has far less strain tolerance than blanket and will crack under severe thermal shock. And because of the binder, the first heat has to be managed: most suppliers publish a bake-out schedule, and heating a board lining too fast through the binder-stabilisation range is a common cause of early cracking. Typical density is 220–400 kg/m³. Ceramic fiber board is more expensive per kilogram than bulk and generally more expensive per square metre than the equivalent blanket thickness, which is why it is used where its rigidity earns its keep rather than as a universal substitute. Modules and Vacuum-Formed Shapes: The Two Derivatives Two products sit just off the main three and are worth naming because they confuse specifications. A ceramic fiber module is not a separate material. It is blanket — folded and compressed, or stacked in cut strips — pre-compressed to roughly 200–260 kg/m³ and fitted with an anchoring system, so that it can be bolted or welded to the furnace shell and then released to expand into place. The compression is deliberate: once installed and released, the module presses against its neighbours and closes the joints between them. Modules buy installation speed and a continuous hot face, and they should be specified as a system — module density, anchor alloy, and the release mechanism all belong on the same line of the enquiry. Vacuum-formed shapes take the board route but into a shaped screen instead of a flat one: cones, riser sleeves, burner blocks, ladle shrouds, custom collars. They are made from bulk-based slurry and are the reason the phrase "vacuum formed" appears on ceramic fiber datasheets that have nothing to do with flat board. If a drawing calls for a shaped ceramic fiber part, it is a vacuum-formed shape made from bulk, not a machined board. Both belong in the same conversation as the three main forms, because the same enquiry frequently contains all five. Why Density Governs High-Temperature Conductivity, Not Form This is the part that a form comparison table cannot show, and it is where most specifications go wrong. At ambient and moderate temperature, heat moves through a ceramic fiber product mainly by conduction along the fibre skeleton and through the still gas in the pores. Under those conditions, lower density is better — less solid path, more still gas — and the low-density forms measure lower. That is the regime the published conductivity figures usually describe, and it is the regime most comparison tables quote, typically at 200 °C or 400 °C mean. Above roughly 600–800 °C the picture changes, because radiation across the pore space starts to dominate. Radiative transfer scales very steeply with absolute temperature, and it is attenuated by the fibre itself: every filament surface in the path absorbs and re-scatters infrared. More fibre per unit volume means more attenuation. So as mean temperature rises, the low-density forms lose their advantage, and the denser forms start to close the gap and then overtake them — until solid conduction through the fibre skeleton begins to climb again and produces a conductivity minimum at a density that itself rises with temperature. Typical figures for standard-grade alumino-silicate fibre make the shift visible: Mean temperature | Ceramic fiber blanket, 128 kg/m³ | Ceramic fiber board, 300 kg/m³ | 400 °C | 0.09–0.13 W/(m·K) | 0.10–0.15 W/(m·K) | 600 °C | 0.13–0.17 W/(m·K) | 0.13–0.17 W/(m·K) | 800 °C | 0.19–0.24 W/(m·K) | 0.18–0.22 W/(m·K) | 1000 °C | 0.27–0.34 W/(m·K) | 0.24–0.30 W/(m·K) | These are indicative ranges for standard grades, not design values — work from your supplier's measured curve for anything that matters. What counts is the shape of the change: the denser ceramic fiber board starts marginally worse and ends measurably better, because it is suppressing a radiative term that the 400 °C column barely shows. Three practical consequences follow. Comparing conductivity figures measured at 200 °C tells you almost nothing about behaviour at 1000 °C. Always ask for the curve, or at least figures at mean service temperature. Specifying the lowest available density in a high-temperature position is often backwards. A ceramic fiber board or a module at 260–320 kg/m³ can outperform a 128 kg/m³ blanket at 1000 °C despite a worse figure on the datasheet, because the denser structure suppresses the radiative component that dominates there. And form matters at high temperature mostly through the density it implies, not through the shape itself. Blanket, board and module at the same density and the same mean temperature perform far more alike than the product names suggest. Form still decides stiffness, erosion resistance and shock tolerance — but it is not the lever that controls high-temperature heat flow. Combined Linings: Where All Three Work Together The most common real furnace lining uses all three forms, and the reason is that each one covers a weakness in the others. A typical full-fibre hot-face construction puts a rigid layer — ceramic fiber board, or ceramic fiber module where fast installation matters — on the hot face, where it resists gas velocity and mechanical contact. Behind it go two or three layers of ceramic fiber blanket, which supply thickness cheaply, absorb the differential movement between the hot face and the shell, and never crack because they are not rigid. Ceramic fiber bulk then goes into the places the flat products cannot reach: around penetrations, behind burner blocks, into the irregular void at the crown, and as compressed packing at expansion joints. The economics are straightforward. Board and module are expensive per square metre and are used thick enough to survive the hot face and no thicker. Ceramic fiber blanket is cheaper per unit thickness and is used to reach the total thermal resistance. Bulk is cheapest of all and is used only where geometry prevents the other two. The combination also fixes the failure modes. A rigid hot face alone cracks under thermal shock; give it a compliant ceramic fiber blanket back-up and the strain is spread through layers that can move. A blanket-only lining erodes at the hot face and compresses at the anchors; give it a board or module hot face and the erosion-prone layer is the one that can take it. A bulk-filled cavity alone settles and leaves a void; use bulk as packing around a structured lining and settling stops mattering, because the structured layers are carrying the thermal duty. Anchor selection sits inside the same decision. Metallic anchors are the economical choice but their usable limit sits well below the fibre's own rating, so a lining running above roughly 1000 °C at the hot face generally needs ceramic anchors or a design that keeps the metal in the cooler back-up layers. How the Three Forms Fail: And What Each Failure Tells You Failure mode is the most useful diagnostic a maintenance team can carry, because each form fails in a characteristic way. Bulk settles. The symptom is a rising shell temperature at the top of a filled cavity or above a penetration, with nothing visibly wrong on the outside. The fix is access and refill, and the prevention is to design so that bulk is never carrying the thermal duty on its own. Blanket tears and erodes. Tearing shows up as splits radiating from anchor points and as mat that has pulled away from the shell. Erosion shows as a thinned, polished hot face with fibre missing in the direction of gas flow, and it is almost always worse near burners, dampers and off-takes. Both point to a specification issue: too low a density, too few anchors, or a gas velocity that required a rigid hot face. Board cracks and shrinks. Cracking appears as straight, full-thickness breaks, usually after a fast heat-up or a severe thermal cycle, and is often the signature of a bake-out schedule that was skipped or compressed. Shrinkage opens gaps at the board joints, and because the joints are straight and continuous, a small shrinkage leaves a straight hot line on the shell — easier to find than blanket failure, and easier to fix with a strip of bulk or a compressible joint filler. Read together, the three failure modes argue for the same specification habit: put the rigid form where the mechanical and gas-velocity load is, put the compliant form where the movement is, and treat bulk as the filler that makes the geometry work. Fibre Chemistry at a Glance: RCF, AES and PCW Form and chemistry are independent axes, and it is worth knowing which one you are choosing on. Refractory ceramic fibre (RCF) is the alumino-silicate standard: 1260 °C for the general-purpose grade, 1360 °C for high-purity and high-alumina grades, and 1430 °C where zirconia is added. It covers the great majority of industrial furnace work and is the cheapest of the three chemistries. Alkaline earth silicate (AES) fibre, sometimes called soluble fibre, is designed for lower bio-persistence and is used where handling and exposure rules push the specification that way. Its temperature capability is lower than RCF and its shrinkage behaviour differs, so a like-for-like substitution is not automatic. Polycrystalline wool (PCW) is mullite or alumina crystal rather than glassy fibre, and it extends the range past 1600 °C at a substantially higher price. It is used where nothing else survives. All three chemistries are available as bulk, blanket and board, so the form decision and the chemistry decision should be made separately and then combined. Where the operating temperature approaches the top of a chemistry's range, the chemistry choice will dominate both cost and service life, and it is worth a dedicated comparison before the form question is settled. Specifying All Three Forms on One Enquiry A mixed order is normal, and the enquiry that gets an accurate quotation back is the one that separates the fields the three forms do not share. - Form and chemistry for each line item — bulk, blanket, board, module or shape, plus RCF, AES or PCW, and the classification temperature in degrees Celsius - Density in kg/m³ — the single most consequential number, and the one most often omitted - Thickness with tolerance, and whether nominal or minimum — matters most for blanket, which is compressible - Dimensions and format — roll width and length, board size and edge profile, module size and anchor type, or the drawing number for a vacuum-formed shape - Continuous and peak service temperature, plus the cycle — how often, and how fast, the lining goes from cold to hot - Atmosphere and gas velocity — oxidising, reducing, or vacuum, and whether there is any entrained dust, slag or alkali - Bake-out constraints — whether the plant can run a controlled first heat, which governs how much binder the board can carry - Test method behind each figure — conductivity measured at what mean temperature, and shrinkage measured against which standard - Quantity, packing and certification — and whether a production sample will be held for comparison against the delivered lot One note on temperature numbers that saves arguments: suppliers quote classification temperature under more than one convention, and the same grade can be listed at different figures depending on whether the criterion is 24-hour property retention or a shrinkage limit. Our own range is graded at 1000, 1100, 1260, 1360 and 1430 °C. Where a datasheet shows a lower figure for what sounds like the same grade, check the test criterion before assuming the products differ — and always specify by continuous service temperature, which is the number that describes what the lining will actually do. Related Reading The selection decision itself — which form for which application, with a decision tree and industry mapping — is covered in ceramic fiber blanket, board, paper and cloth compared. For the bulk end in depth, including grades, shot content and application methods, see ceramic fiber bulk: grades and uses. The procurement side of the flexible forms is covered in our rope, tape, cloth and paper buying guide, and raw material chemistry and fibre production are set out in ceramic fiber raw materials and manufacturing. Where the choice is between board materials rather than forms, see refractory board selection: calcium silicate and ceramic fiber, calcium silicate vs ceramic fiber board and ceramic fiber vs rock wool for furnace linings. Above the RCF range, polycrystalline wool vs standard ceramic fiber sets out where PCW earns its cost. Product ranges: ceramic fiber blanket, ceramic fiber board, ceramic fiber bulk, ceramic fiber modules and vacuum-formed special shapes. FAQ: Q: Is ceramic fiber bulk just the raw material for the other forms? A: Largely, yes, and that is the useful way to think about it. Bulk is the loose fibre as it comes off the fibre line at 60–100 kg/m³, with no structure imposed on it. It is the feedstock for vacuum-formed ceramic fiber board and shapes, and for most textile products. It is also sold in its own right for filling irregular cavities, packing around penetrations, stuffing expansion joints, and as a lightweight aggregate in castables. What bulk cannot do is hold a designed thickness on its own, because loose fibre consolidates under vibration and thermal cycling and leaves a void at the top of a cavity. Q: Why does ceramic fiber blanket have no binder but board does? A: Because the two forms get their strength from different mechanisms. Blanket is needled: barbed needles are driven through the fibre mat so the filaments mechanically interlock through the full thickness, which needs nothing added. Board is vacuum formed: the fibre is dispersed in a water slurry, an inorganic binder is added, and vacuum pulls the water out so fibre and binder deposit as a rigid solid. The binder is what lets a ceramic fiber board be cut, drilled and anchored, and it is also why board has to be heated through a controlled bake-out on first firing while blanket does not. Q: Which ceramic fiber form has the lowest thermal conductivity? A: It depends entirely on the temperature, and that is the point most specifications miss. At ambient and moderate temperature the low-density forms measure lower, because conduction through the fibre skeleton and the still pore gas dominates and less solid material means less path. Above roughly 600–800 °C radiation across the pores takes over, and radiation is attenuated by fibre surface — so the denser forms close the gap and then overtake. A ceramic fiber board or module at 260–320 kg/m³ can outperform a 128 kg/m³ blanket at 1000 °C despite a worse figure on the datasheet. Always compare conductivity at mean service temperature, not at 200 °C. Q: Can ceramic fiber bulk replace blanket in a furnace lining? A: Not in a position that has to hold a specified thermal resistance. Bulk has no tensile strength, no erosion resistance, and it settles — under its own weight, under vibration and under thermal cycling — so a bulk-filled cavity develops a void at the top and a hot spot on the shell. Bulk is correctly used as a supplement: filling irregular voids, packing around penetrations and burner blocks, and as compressible joint filler in a lining whose thermal duty is carried by blanket, board or modules. If the drawing shows bulk as the working layer, it is worth asking why before ordering. Q: Why does ceramic fiber board crack when blanket does not? A: Strain tolerance. A needled ceramic fiber blanket is compliant: when the lining cycles from cold to hot, the mat compresses and recovers instead of fracturing, and it has no binder that has to stabilise. A ceramic fiber board is rigid by design, so it has far less capacity to absorb differential movement, and cracking is the expected result of severe thermal shock or of heating too quickly through the range where binder residues and moisture leave the section. Straight, full-thickness breaks appearing after a fast heat-up almost always point to a compressed or skipped bake-out schedule rather than to a defective board. Q: Are ceramic fiber modules blanket or board? A: Modules are blanket — folded or stacked blanket, pre-compressed to roughly 200–260 kg/m³ and fitted with an anchoring system so the whole unit can be fixed to the shell and then released to expand into place and close the joints against its neighbours. They are not a separate chemistry and not a vacuum-formed product. The practical consequence is that a module should be specified as a system: module density, the anchor alloy and the release mechanism all belong on the same line of the enquiry, because anchor temperature limits are usually the binding constraint rather than the fibre. Q: What temperature grades does ceramic fiber come in? A: Our range is graded at 1000, 1100, 1260, 1360 and 1430 °C classification temperature, with polycrystalline wool extending past 1600 °C for the highest-duty positions. Note that suppliers quote classification temperature under more than one convention, so the same grade is sometimes listed at a different figure depending on whether the test criterion is 24-hour property retention or a shrinkage limit — check the criterion before assuming two datasheets describe different products. In every case, specify by continuous service temperature, which for oxidising atmospheres normally sits 150–200 °C below the classification figure and can sit further below in reducing or vacuum atmospheres. ### Alumina & Zirconia Ultra-High-Temperature Fiber: A Buyer's Guide URL: https://www.rosetexwool.net/news/alumina-zirconia-ultra-high-temperature-fiber/ 2026-09-14 | Author: Rosetexwool Editorial | Category: industry insight Summary: Engineering guide to alumina and zirconia ultra-high-temperature fiber: five temperature tiers, AZS vs Y-PSZ selection, sol-gel manufacturing, shrinkage and CMAS limits above 1600 C. The moment a furnace hot face climbs past about 1600 °C, the usual insulation vocabulary changes. Standard refractory ceramic fiber (RCF) and soluble fiber have already reached the end of their reliable life. Polycrystalline alumina and mullite fiber can carry the load for another 200–300 °C, but eventually they too hit a wall. That wall is where alumina-zirconia-silica (AZS) fiber and yttria-stabilized zirconia (Y-PSZ) fiber take over. This guide is written for buyers and specifiers who search for alumina wool panel, high alumina wool or want to buy high temperature zirconia insulation. The product name alone does not define performance. What matters is the material family, its real continuous use temperature, the phase changes it will undergo in service, and the failure mode that will end its life. Get those four things right and the insulation system will outlast the campaign. Get them wrong and a 2200 °C label will not save the lining. Because the terms are used loosely in commerce, a search for alumina wool panel may return anything from non-glass high-alumina blanket to rigidized mullite board, while buy high temperature zirconia insulation may point to AZS felt, Y-PSZ loose wool or even alumino-silicate wool with a small zirconia addition. The rest of this article gives the engineering boundaries that separate those products. Why 1600 °C is the line where standard ceramic fiber stops Below roughly 1350 °C, glass-state aluminosilicate fibers dominate industrial insulation. They are flexible, low-cost and easy to convert into blankets, papers, modules and boards. Their weakness is that the glassy structure is thermodynamically unstable. Between 1000 °C and 1200 °C, amorphous alumino-silicate begins to devitrify, forming cristobalite and mullite. That crystallization is accompanied by shrinkage, loss of resilience and, in blanket linings, joint opening and local hot spots. The result is a hard boundary: RCF can be classified at 1260–1430 °C, but its practical continuous use temperature in most industrial atmospheres is closer to 1000–1260 °C. Above that, the fiber spends its service life destroying its own structure. This is not a problem that can be solved by simply raising the alumina content inside a glass-state fiber. High-alumina RCF delays devitrification slightly, yet it is still produced by melt-spinning and still contains a glass phase. Once that glass begins to crystallize in service, the same shrinkage and embrittlement occur. That is why the step above 1400–1600 °C is not a linear extension of RCF chemistry — it is a change of material route. The five temperature tiers of industrial insulation fiber We group industrial insulation fibers into five tiers. The first three are covered in detail elsewhere on this site; this article owns Tier 4 and Tier 5. Tier | Material family | Continuous use window | Why it survives | 1 | Low-alumina AES / standard RCF | ≤ ~1050 °C | Low cost, flexible, easy to install | 2 | High-alumina RCF / ASW | ~1100–1350 °C | Higher Al₂O₃ delays devitrification, but still glass-state | 3 | PCA / PCW / mullite fiber | ~1400–1600 °C | Pre-crystallized; no massive in-service devitrification | 4 | AZS alumina-zirconia-silica fiber | ~1500–1700 °C | Multi-phase design suppresses creep and crack growth | 5 | Y-PSZ yttria-stabilized zirconia fiber | ~1800–2200 °C | Stabilized cubic/tetragonal ZrO₂; virtually no glass phase | These ranges are engineering boundaries, not supplier guarantees. Within each tier, density, impurity level, atmosphere and thermal cycling can move the practical limit up or down by more than 100 °C. A classification temperature printed on a datasheet is therefore only the first filter, not the design temperature. What "classification temperature" really means Three temperature concepts are routinely confused. Treating them as interchangeable is one of the most expensive mistakes in high-temperature specification. - Classification temperature is the temperature at which a fiber can pass a standardized short-term test. It is useful for sorting products into grades, but it says nothing about 5000-hour life. - Continuous use temperature is the hot-face temperature the material can tolerate for the design life under the actual atmosphere, load and cycle. It is always lower than the classification temperature, often by 100–300 °C. - Short-term limit is the maximum temperature the material can survive without catastrophic failure in a controlled test. It must not be converted into a 24-hour or long-term rating. For example, a Y-PSZ blanket may be associated with a 2200 °C short-term capability in manufacturer literature, but that does not mean it can be left at 2200 °C indefinitely in an oxidizing, dusty furnace with mechanical vibration. The real continuous use temperature is more likely 1800–2000 °C, and only after the supplier has confirmed the density, stabilizer content and impurity limits for the batch. This distinction between classification temperature and continuous use temperature applies to every tier, but it becomes critical — and expensive — above 1600 °C. Tier 1–2: Glass-state aluminosilicate fibers — where they win and fail RCF and alkaline-earth silicate (AES) wool win on cost, flexibility and supply chain maturity. They can be needled into blankets, converted into papers and ropes, and folded into modules. Their continuous-use ceiling is set by devitrification, not by melting. As the glass phase crystallizes, the fibers become rigid and brittle, and the blanket loses the spring-back that keeps joints tight. High-alumina RCF pushes the Al₂O₃ content toward 50–70 wt%, but the manufacturing route is still melt-spinning. The fiber remains predominantly glassy, so it still devitrifies in service. high alumina wool is therefore not a safe shorthand for "high-temperature wool." Unless the specification also demands a pre-crystallized structure, a supplier could deliver a non-glass high-alumina fiber that fails the same way standard RCF does. For the 1000–1350 °C range, RCF and AES remain excellent choices when chemical attack is not severe and maintenance access is available. Once the design hot face moves above ~1350 °C for long periods, the economics shift toward pre-crystallized fibers. Tier 3: Polycrystalline alumina & mullite fiber — the pre-crystallized upgrade Polycrystalline alumina (PCA), polycrystalline wool (PCW) and mullite fiber are produced by sol-gel or precursor spinning, not by melt-spinning. The key difference is that the major crystallization happens during manufacture. The delivered fiber is already dominated by α-Al₂O₃ and/or 3Al₂O₃·2SiO₂ (mullite), so there is far less in-service phase change to drive shrinkage. A typical mullite composition is 72–75 wt% Al₂O₃ and 25–28 wt% SiO₂. PCA products may be higher in Al₂O₃. Their continuous-use window is roughly 1400–1600 °C, with short-term excursions toward 1650–1800 °C depending on density and impurity level. Linear shrinkage at 1500 °C is commonly below 2.5% for quality grades, but the exact figure must be tied to a test temperature, hold time and pre-load. This tier is the direct upgrade path from RCF. Our polycrystalline mullite fiberboard and polycrystalline fiber modules sit here, covering rigid boards and folded module systems for furnace linings up to about 1900 °C classification. For many heat-treatment, ceramics and metal-processing furnaces, Tier 3 is the right economic choice. Tier 4: Alumina-zirconia-silica (AZS) fiber — the 1500–1700 °C workhorse When the hot face sits between 1500 °C and 1700 °C, a simple high-alumina fiber is no longer enough. The material needs zirconia. AZS fiber is an Al₂O₃–ZrO₂–SiO₂ system, typically with 55–75 wt% Al₂O₃, 10–25 wt% ZrO₂ and the balance SiO₂. The zirconia exists mainly as tetragonal ZrO₂, pinned by the alumina-silica matrix, and acts as a second-phase strengthener that slows creep, crack growth and grain-boundary sliding. AZS is not "mullite with extra ZrO₂." It is a multi-phase engineering material. During service it can undergo further mullitization, ZrO₂ coarsening and, if the silica or impurity level is too high, formation of zircon (ZrSiO₄) and cristobalite. Those secondary phases can embrittle the fiber and cause powdering. The balance between Al₂O₃, ZrO₂ and SiO₂ therefore matters more than the classification temperature. AZS is the natural home of alumina zirconia fiber when the application needs a flexible or shaped hot-face layer in the 1600–1700 °C range and the budget does not justify Y-PSZ. The term alumina zirconia fiber is sometimes applied to any aluminosilicate fiber that contains a small zirconia addition, but in the strict engineering sense it describes the high-zirconia AZS system used above 1500 °C. It is used in laboratory furnaces, specialty kilns, high-temperature filters and furnace hot-face repair layers. Tier 5: Yttria-stabilized zirconia (Y-PSZ) fiber — the 1800–2200 °C ceiling Pure ZrO₂ transforms from high-temperature cubic, through tetragonal, to low-temperature monoclinic on cooling. That t→m transformation is accompanied by a 3–5% volume expansion — enough to destroy a fiber mat or a rigid lining. The solution is a stabilizer, most commonly 3–8 wt% Y₂O₃, which locks the structure in the cubic/tetragonal t′ phase. Y-PSZ fiber contains more than 90–95 wt% ZrO₂. It has virtually no glass phase and can operate continuously around 1800–2200 °C in clean, oxidizing atmospheres. It is the material people reach for when they want to buy high temperature zirconia insulation for crystal growth, vacuum heat treatment, aerospace thermal protection, rocket-nozzle linings or ultra-high-temperature research furnaces. yttria stabilized zirconia fiber is not a single commodity. The stabilizer content, impurity level, density and fiber architecture all shift the practical continuous use temperature. A loose wool feels very different from a vacuum-formed board, and a hollow-fiber felt at 38 mg/cm³ has a thermal conductivity far below that of a dense Y-PSZ body. Anyone specifying yttria stabilized zirconia fiber must therefore lock density and form before comparing numbers. The weaknesses of Y-PSZ are different from those of lower-tier fibers. Instead of devitrification, the risks are: - t′ phase decomposition: long exposure above ~1200 °C can gradually break down the metastable t′ phase, allowing t→m transformation on cooling. - Sintering: high temperature accelerates diffusion, closes pores and raises effective thermal conductivity. - CMAS attack: calcium-magnesium-alumino-silicate melts can dissolve Y₂O₃ and destabilize the fiber. - Brittleness: Y-PSZ is the most fragile of the five tiers and needs careful support and gradient design. Head-to-head: AZS vs Y-PSZ selection matrix The choice between AZS and Y-PSZ is rarely about a single temperature. It is about the combination of temperature, chemistry, cycling and budget. Criterion | AZS fiber | Y-PSZ fiber | Continuous hot face | ~1500–1700 °C | ~1800–2200 °C | Main chemistry | Al₂O₃–SiO₂–ZrO₂ multi-phase | >90% ZrO₂, Y₂O₃-stabilized | Thermal conductivity | Moderate; rises with density and aging | Very low in porous felts; higher in dense bodies | Thermal shock | Better than Y-PSZ due to residual glass/second phases | Good when t′ is stable; poor after sintering | Chemical resistance | Good in clean oxidizing air; sensitive to basic slag and glass | Excellent in many oxide melts; attacked by CMAS | Formability | Flexible blankets, boards, shaped pieces | Loose wool, felts, fabrics, vacuum-formed shapes | Relative cost | High, but below Y-PSZ | Highest of the five tiers | Dominant failure | Mullitization, ZrO₂ coarsening, liquid-phase softening | t′ decomposition, sintering, CMAS penetration | If the hot face is 1650 °C in a clean furnace and the design needs boards or complex shapes, AZS is usually the more rational choice. If the hot face exceeds 1900 °C, or if chemical purity and extreme inertia are mandatory, Y-PSZ becomes necessary. Manufacturing routes: why melt-spinning fails above 1600 °C RCF is made by melting alumino-silicate and then blowing or spinning the melt into fibers while it is still viscous. That route works because the melt temperature is manageable and the glass phase keeps the fiber flexible. High-alumina, AZS and Y-PSZ compositions cannot be melt-spun economically for three reasons: - The melt temperature would be far higher, consuming refractory crucibles and energy. - The melt crystallizes too quickly to form continuous, fine fibers. - Contamination from the crucible and atmosphere becomes severe at those temperatures. Instead, these fibers are made by sol-gel or precursor spinning. Metal salts or alkoxides are hydrolyzed and condensed into a viscous, spinnable sol. The sol is spun into precursor fibers by dry spinning, centrifugal spinning or electrospinning. The fibers are then dried, pre-sintered to remove organics and hydroxyl groups, and finally calcined at high temperature to convert them into crystalline oxides. The sol-gel route is what makes yttria stabilized zirconia fiber and high-purity alumina fiber commercially possible: it distributes the Y₂O₃ stabilizer uniformly through the precursor and keeps the final grain size small enough to retain the toughened t′ phase. This route controls composition, fiber diameter and phase distribution far better than melt-spinning, but it is also more expensive and less suited to very large, dense or highly complex shapes. That manufacturing reality is what separates the "market name" from the "deliverable product." Thermal conductivity, shrinkage and phase change: what the datasheet hides Thermal conductivity of a fiber mat is not a single number. It is the sum of solid conduction through the fibers, gas conduction through the pores, and radiation across the pores. Above 800 °C, radiation becomes increasingly important, so the effective conductivity rises faster than a linear interpolation would predict. Published fits for aluminosilicate fiber give an exponent of roughly 1.3–1.5 on absolute temperature. Reported values for polycrystalline mullite fiber are around 0.336 W/(m·K) at 1300 °C and 0.384 W/(m·K) at 1400 °C for typical blanket densities. Those are useful anchor points, but they cannot be transplanted to a different density, thickness or atmosphere. Hollow Y-PSZ fiber felts have been reported as low as 0.019 W/(m·K) at room temperature and 0.103 W/(m·K) at 1000 °C, but those values belong to laboratory structures around 38 mg/cm³ and do not describe a dense Y-PSZ board. For comparison, a dense Y-PSZ body may read 1.5–2.5 W/(m·K), an order of magnitude higher than the porous felt. Shrinkage is a structural health indicator, not just a dimensional tolerance. It tracks the same processes that degrade insulation performance: crystallization, sintering and grain growth. A blanket that shrinks 2% at temperature may also have lost the spring-back that keeps seams closed, which can create hot spots even if the average thickness looks acceptable. Material | Dominant shrinkage driver | Typical design control | RCF / AES | Devitrification to cristobalite and mullite | Keep below continuous-use limit | PCA / PCW | Residual glass crystallization, grain growth | Pre-crystallized route, impurity control | AZS | Mullitization, ZrO₂ coarsening, liquid-phase softening | Control ZrO₂ and SiO₂, long-term aging tests | Y-PSZ | t′ decomposition, sintering, pore closure | Stabilizer control, limit CMAS exposure | Chemical stability: molten metals, slag, CMAS and atmosphere limits Alumina and zirconia are more chemically inert than glass-state fibers, but "inert" is always conditional. Silica-rich RCF, PCW and AZS are attacked by strong alkalis, basic slags, glass melts and fluorine-bearing atmospheres. In those environments, liquid silicates can penetrate along grain boundaries and accelerate softening. High-purity Y-PSZ resists many oxide melts, yet it is not immune. CMAS deposits can dissolve the Y₂O₃ stabilizer, destabilize the t′ phase and trigger t→m transformation on cooling. Alkaline oxide slags, fluorides and metals that form low-melting compounds with ZrO₂ also require separate testing. In reducing, vacuum or carbon-rich atmospheres, silica in the matrix can react: SiO₂ + C → SiO↑ + CO↑ That reaction is controlled by temperature, oxygen partial pressure and catalytic surfaces. Air-oxidation data therefore cannot be extrapolated to a hydrogen furnace, vacuum furnace or active-metal process. Any UHT specification must state the atmosphere and the chemical species the hot face will contact. Specifying UHT fiber: what to put on the purchase order A product name such as alumina wool panel, high alumina wool or buy high temperature zirconia insulation is the starting point, not the specification. The phrase zirconia insulation alone can describe an alumino-silicate fiber with a few percent ZrO₂, a high-zirconia AZS felt or a Y-PSZ vacuum-formed shape — three very different products. Likewise, alumina zirconia fiber is sometimes attached to anything that contains both oxides, even when the zirconia level is too low to influence the 1600 °C boundary. A robust purchase order should therefore lock at least the following boundaries: - Chemistry: Al₂O₃ / SiO₂ / ZrO₂ / Y₂O₃ ranges and impurity limits for Fe, Na, K, Ti and others. - Phase: required main phases and allowed secondary phases after aging. - Temperature: continuous hot face, short-term peak, heating/cooling rate and cycle count. - Atmosphere: oxidizing, reducing, vacuum, inert gas or chemical vapor exposure. - Density and thickness: with tolerances, because conductivity and strength depend on them. - Linear change: test temperature, hold time, preload and acceptance limit. - Thermal conductivity: test conditions including hot-face, cold-face and mean temperatures. - Form and size: blanket, board, module, vacuum-formed shape or loose wool; maximum dimensions. - Mechanical loads: compression, vibration and anchoring requirements. - Safety: SDS, cutting and machining controls, waste handling. When a supplier cannot provide project-specific corrosion, aging or phase-stability data, the safest path is to run a coupon test before committing the full lining. Bottom line: match the material to the failure mode Above 1600 °C, the correct answer is not "a higher grade of RCF." It is a switch to a pre-crystallized or fully oxide fiber. The selection sequence is: - Define the real hot-face temperature, cycle, atmosphere and chemical exposure. - Eliminate any material whose continuous-use boundary is below the design condition. - Compare the remaining candidates by their dominant failure mode: devitrification for RCF, grain growth for PCW, liquid-phase softening for AZS, t′ decomposition and CMAS for Y-PSZ. - Specify chemistry, phase, density and test conditions rather than a trade name. For the 1400–1600 °C range, our polycrystalline mullite fiberboard and polycrystalline fiber modules provide a proven, pre-crystallized solution. For 1600–1700 °C, AZS fiber becomes the rational candidate. Above 1800 °C, only Y-PSZ can carry the thermal and chemical boundary. In every case, the material must be matched to the failure mode, not to the highest number on a datasheet. If you are evaluating an alumina wool panel for a furnace hot face, start with the continuous use temperature and the expected shrinkage at that temperature, not the alumina percentage. If you want to buy high temperature zirconia insulation, decide first whether the application needs AZS or Y-PSZ, because the cost and failure modes differ by an order of magnitude. A well-written specification turns a vague request for zirconia insulation or alumina zirconia fiber into a deliverable product with traceable chemistry, phase stability and tested performance. For furnace lining applications that combine alumina and AES materials by zone, see Alumina & AES in ultra-high-temperature furnaces. FAQ: Q: Is 1700 C hot enough to need Y-PSZ, or will AZS work? A: For most 1500–1700 C clean oxidizing furnaces, AZS is the rational first choice. Y-PSZ becomes necessary when the continuous hot face approaches 1800 C, when extreme chemical purity is required, or when the application cannot tolerate the failure modes of AZS such as liquid-phase softening. The final decision should be confirmed by thermal cycling and aging tests. Q: Why can't high-alumina RCF simply be used at higher temperatures? A: High-alumina RCF is still manufactured by melt-spinning and remains predominantly glassy. Above 1000–1200 C it devitrifies, forming cristobalite and mullite, which causes shrinkage, embrittlement and joint opening. Raising the alumina content delays but does not eliminate this process. Pre-crystallized PCA or AZS fibers are needed because the major phase change is completed during manufacture. Q: Can alumina wool panels replace refractory bricks? A: Alumina wool panels are attractive where low thermal mass, fast heat-up, complex shape or low conductivity is needed, typically up to about 1600 C continuous. They are not a direct replacement for refractory bricks in high-abrasion, heavy-load or severe slag-contact zones. In those areas a gradient lining — rigid fiber backed by dense refractory — is usually safer. Q: Is zirconia insulation always the best choice above 1800 C? A: Y-PSZ zirconia insulation is the only practical fiber option for many 1800–2200 C applications, but it is not automatically the best choice. It is brittle, expensive and vulnerable to CMAS attack and t′ phase decomposition. If the atmosphere is dusty, contains alkaline oxides, or the component sees heavy mechanical loading, a different hot-face architecture may be required. Q: What does a 2200 C rating actually mean on a zirconia datasheet? A: It usually indicates a short-term upper capability under controlled conditions, not an unlimited continuous-use temperature. The practical continuous-use window for Y-PSZ is more commonly 1800–2000 C, depending on density, stabilizer content, impurity level and atmosphere. Always ask the supplier for the continuous-use temperature and shrinkage data at your specific design conditions. Q: Are polycrystalline alumina and AZS fibers safer than standard RCF? A: PCA and AZS have different chemistry from standard RCF, but any high-temperature fiber can release respirable particles during cutting, machining or removal. Safety should be managed by following the SDS, using local exhaust ventilation, HEPA collection, appropriate respiratory protection and safe waste disposal — not by assuming a material is harmless because of its chemistry. Q: What information must a buyer request from a UHT fiber supplier? A: At minimum: Al2O3/SiO2/ZrO2/Y2O3 ranges and impurity limits; main and allowed phases after aging; continuous-use temperature and short-term limit; linear change with test conditions; thermal conductivity at the design hot and cold faces; density and thickness tolerances; atmosphere compatibility; form and maximum dimensions; and a project-specific coupon or aging test plan. ### Alumina & AES in Ultra-High-Temperature Furnaces: Hot-Face, Backup & Maintenance Zone Selection URL: https://www.rosetexwool.net/news/alumina-aes-furnace-lining-applications/ 2026-09-14 | Author: Rosetexwool Editorial | Category: industry insight Summary: Specify alumina, mullite/PCW, and AES by furnace zone—not brand. Get a graded-lining framework, process matrix, and RFQ checklist. Why Furnace Lining Selection Is a Zonal Problem, Not a Fibre Brand Choice In ultra-high-temperature furnace engineering, the wrong question is “which fibre is best?” The right question is “which zone should each material serve?” A furnace lining is a graded system: the hot face carries flame radiation, chemical attack, and mechanical load; the transition layer cuts heat flux; the backup layer controls cold-face temperature and maintenance access. Alumina wool, mullite / polycrystalline wool (PCW), and alkaline earth silicate (AES) wool each have a valid place, but only when the local temperature and chemistry place them inside their qualified range. For procurement teams, the real choice is usually alumina wool at the hot face and AES wool backup insulation in the cooled zones. The practical rule is simple: if the hot-face temperature is above the AES continuous-service ceiling, the hot face must be an alumina-family or qualified dense refractory system. AES can only enter where the thermal profile has cooled into its safe band. This single boundary prevents most over-temperature failures, premature shrinkage, and uncontrolled devitrification in high temperature furnace insulation projects. The 1200 °C Rule That Prevents Over-Temperature Failures AES wool is generally qualified for continuous service up to about 1200 °C, with selected grades extending toward 1300 °C when the atmosphere, density, and anchorage are favourable. Above that band, the fibre begins to devitrify and shrink. The result is not merely a loss of insulation value; it can become a brittle, dusty layer that accelerates hot-face failure. For any zone expected to exceed roughly 1200 °C continuously, the default material family must shift to alumina refractory fibre, mullite, or PCW. This boundary is the first gate. Every other decision—product form, density, anchor spacing, and sealing—comes after it. What This Page Will and Will Not Claim This page explains how to allocate materials across furnace zones. It does not rank suppliers, guarantee a specific temperature for every product, or claim that any single fibre is “safe” regardless of duty. All temperature figures are screening inputs. The final specification must be confirmed against the supplier’s technical data sheet (TDS), the project thermal profile, and, where necessary, coupon or field testing. Material Families: Alumina, Mullite/PCW, and AES Understanding the chemistry is the starting point. Product form, density, and installation quality define the limit. Alumina-Based RCF: A Composition Range, Not a Universal 52 % Rule High-alumina refractory ceramic fibre (RCF) is an amorphous alumina-silica material in which the Al₂O₃ content is raised above standard RCF grades. A commonly cited commercial example sits near 52 % Al₂O₃ with a classification temperature around 1425–1500 °C. That example is useful, but it is not a global definition of the category. Different producers use different Al₂O₃ ranges, zirconia additions (often described as zirconia insulation additions), impurity limits, and forming routes. For procurement, the important fields are the full oxide analysis, the fibre diameter distribution, the shot or unfiberized content, the density, and the test basis for every claimed value. Alumina wool is the right starting point for hot-face zones above the AES limit, but the exact grade must be matched to the duty. For severe atmospheres, some alumina wool grades are modified with zirconia insulation stabilizers; the ZrO₂ content and its qualified atmosphere must still be verified. See how the alumina-zirconia ultra-high-temperature tier fits above 1500 °C. Mullite, PCW, and Ceramic Fiber Modules Are Not Synonyms - Mullite refers to the crystalline phase near 3Al₂O₃·2SiO₂. - PCW (polycrystalline wool) normally describes sol-gel-derived crystalline fibres with a high alumina content, often applied above 1300 °C. - A ceramic fiber module is a product geometry—folded or stitched blanket on an anchor system—not a chemistry. A mullite fiber module or ceramic fiber module may be PCW-based, or it may use another high-alumina system. The specification should name the fibre chemistry, crystalline phase, forming route, and component form. Learn more about the PCW family in Polycrystalline Wool Fiber vs Standard Ceramic Fiber. For the highest-temperature zones, PCW / mullite modules from suppliers such as Rosetex Wool’s polycrystalline-mullite-fiberboard line are engineered for 1600–1900 °C service when the grade and atmosphere are qualified. Module installation details are covered in Polycrystalline Fiber Modules: Spec, Installation & Applications. AES: Alkaline Earth Silicate Wool and Its Correct Service Boundary AES wool is a CaO–MgO–SiO₂ man-made vitreous fibre. It is also supplied as bio soluble ceramic fiber or bio-soluble ceramic fiber. Its chemistry is fundamentally different from alumina-silicate systems, which is why the same selection logic cannot be used. Representative compositions show silica of 50–82 wt % and CaO + MgO of 18–43 wt %, with alumina and other minor oxides below 6 wt %. This composition explains why AES should not be selected by Al₂O₃ content. Its value is in lower-temperature zones, backup layers, personnel-access areas, gaskets, expansion joints, and removable covers—locations where the local temperature stays within the supplier’s qualified continuous-service range. AES wool backup insulation is a valid engineering choice, but only after the thermal gradient has been verified. For the full temperature tier map, see High-Temperature Insulation Wool: Temperature Ratings & How to Choose. Temperature and Chemistry: The Two Non-Negotiable Gates A furnace lining fails when either temperature or chemistry is underestimated. The two interact, and either can move the safe limit well below the nominal classification temperature. Continuous Service, Classification, and Reheat Limits Must Not Be Mixed - Classification temperature is a laboratory reheat value, often measured over 24 hours. - Continuous service temperature is the steady-state operating limit the supplier qualifies for a specific grade. - Reheat change limit is the allowable permanent linear change at a stated temperature and time. A 1600 °C classification does not mean the material can carry 1600 °C continuously in a reducing, alkali-laden, high-velocity environment. Procurement should require the continuous service temperature under the project atmosphere and the permanent linear change under the same conditions. Always state the continuous service temperature in the RFQ so suppliers cannot hide behind a single classification figure. How Atmosphere and Contaminants Move the Real Limit Downward High hot-face temperatures accelerate fibre devitrification and creep. Alkali vapours (Na₂O, K₂O), halides (Cl, F), sulfur compounds, heavy-metal vapours, and slag dust can all drop the safe limit. In glass and cement kilns, alkali attack is often the controlling factor. In waste incinerators, chlorides and fluorides form low-melting phases. In petrochemical heaters, sulfur and vanadium can alter refractory chemistry. The material family tells you where to start; project-specific testing tells you where to stop. Process-by-Process Application Matrix The same material family performs differently in different furnaces. The matrix below maps representative hot-face bands to material choices and AES entry rules for common kiln lining and furnace lining projects in high temperature furnace insulation. For a furnace-specific material comparison, see Ceramic Fiber vs Rock Wool for Furnace Linings. Process | Representative hot-face band | Preferred hot-face system | AES permission and location | Primary risks | Ceramic shuttle / tunnel kiln | 1200–1400 °C | High-alumina RCF or PCW / mullite module | Backup or lower-temperature zones after gradient verification | Thermal cycling, dust, glaze alkali | Glass melting furnace | 1500–1600 °C | Dense refractory plus qualified high-temperature insulation | Deep backup only; exclude vapour-exposed hot face | Alkali / halide vapour, corrosion | Steel reheating / soaking furnace | 1100–1300 °C | High-alumina RCF, PCW / mullite, or dense shapes | Cooler backup, doors, and joints | Scale, gas velocity, atmosphere shifts | Cement rotary kiln | 1400–1450 °C | Dense alumina-mullite or chemistry-specific refractory | Not at the hot face; only outer or protected backup | Alkali, dust, load, rotation | Petrochemical heater | 800–1000 °C+ | High-temperature RCF, PCW / mullite, or dense shapes | Convection / backup only, subject to TDS confirmation | Hydrocarbon, sulfur, thermal shock | Waste incinerator | 1100–1200 °C | Corrosion- and wear-specific hot-face refractory | Protected, cooler backup only | Cl / F / alkali / metal condensates | Ceramic Shuttle and Tunnel Kilns Ceramic kilns fire in oxidizing atmospheres with repeated thermal cycling. Representative firing zones run from about 1200 °C to 1400 °C. For the crown, roof, or wall exposed to the firing atmosphere, the starting point is a high-alumina or mullite polycrystalline fiber system selected against the peak hot-face temperature. AES wool blanket or board can sit in the backup once the interface temperature is proven to stay below its limit. The main risks are thermal cycling, airflow, abrasive dust, flame impingement, and alkali from glazes and raw materials. Glass Melting Furnaces Glass melting is one of the most aggressive environments. Crown, breastwall, and port zones may exceed 1500 °C and are exposed to volatile Na₂O, K₂O, boron compounds, and halides. AES should not be positioned as the hot-face insulation here. The hot-face system should be selected from high-temperature aluminosilicate, mullite, AZS, fused-cast, or other qualified glass-contact and vapour-zone refractories. AES may enter only in a deep, well-sealed backup layer after vapour penetration, condensate chemistry, and interface temperature have all been confirmed. Steel Reheating and Soaking Furnaces Reheating and soaking furnaces typically operate around 1100–1300 °C, with localized oxidation, CO fluctuations, scale dust, and high-velocity combustion gases. For walls, roofs, and doors directly exposed to the furnace atmosphere, alumina refractory fibre or PCW / mullite is more appropriate than AES. AES is suitable for cooler backup layers, external piping, door interiors where the gradient permits, maintenance-access areas, and expansion joints. Cement Rotary Kilns The cement burning zone runs near 1400–1450 °C with strong alkali and clinker dust. This is a dense-refractory-dominated environment. Alumina-mullite, magnesia-spinel, or other chemistry-specific bricks and monolithics should be selected against kiln atmosphere, coating stability, mechanical load, and thermal cycling. AES is not appropriate for the hot face. See our cement kiln thermal protection guide for a deeper case study. Fibrous insulation may be used in an outer lining or behind a dense working lining where thermomechanical design and interface temperature allow. Petrochemical Heaters Petrochemical heater radiant sections expose tube supports, walls, and shields to high heat. The brief lists 800–1000 °C at the tube surface, but radiant-facing surfaces can be hotter. The specification must distinguish between the process-fluid temperature, the tube-skin temperature, and the refractory hot-face temperature. See the petrochemical reformer furnace reline case study for a field example. High-alumina RCF, PCW / mullite, and dense shapes are candidates for high-temperature radiation-section components. AES is credible only in cooler convection sections, pipe covers, expansion joints, or backup zones, and only after the supplier confirms hydrocarbon, sulfur, steam, and thermal-cycling compatibility. Waste Incinerators Waste incinerators can contain Cl, F, alkali metals, sulfur, and heavy-metal vapours. The primary lining must be selected against the corrosion mechanism and mechanical wear. AES may be used in a cooler, protected backup zone. It should not be treated as a universal corrosive-environment replacement for RCF or PCW. Graded Lining Architecture: Hot Face → Transition → Backup A reliable kiln lining or furnace lining is normally arranged as a graded lining temperature gradient: - Hot-face layer: carries flame radiation, process temperature, chemical attack, erosion, and mechanical loading. - Transition or high-temperature insulation layer: reduces heat flux and bridges the gap between the hot-face material and cooler insulation. - Backup or safety layer: provides most of the cold-face temperature control and may improve maintainability. For example, a 1350–1450 °C furnace might combine a high-alumina or mullite hot-face ceramic fiber module with a high-alumina blanket or board transition and an AES backup insulation board or blanket. This graded lining stack is only an illustration. The actual transition point must come from thermal modelling and supplier data. For board specifications up to 1900 °C, see Polycrystalline Mullite Board: Ultra-High-Temp 1900 °C. When AES Enters the System Before selecting AES for any layer, the engineer should: - Establish the maximum and typical hot-face temperature. - Determine the local gas and refractory temperatures at each interface. - Model steady-state and relevant transient conditions. - Add margins for hot spots, nonuniform heating, process upsets, and anchorage conduction. - Compare the calculated AES surface temperature with the supplier’s continuous-service rating for the exact grade. - Document the basis, including atmosphere, thickness, density, facing, and fixing method. If the interface temperature is unknown, AES should not be selected by subtracting a generic “200 °C per layer” rule of thumb. Product Form Follows Duty, Not Generic Material Family Product form | Preferred duty | Key limitation | Module | Large roofs and walls; precompressed anchorage | Anchor design and module alignment are critical | Blanket | Complex shapes, wraps, and infill | Compression and erosion control must be specified | Board or rigid panel | Burners, doors, and seals requiring shape retention | Edge erosion and thermal-shock design require verification | Paper or felt | Gaskets and thin seals | Not a structural hot-face substitute | Dense castable, brick, or preform | High-wear or chemical-attack zones | Often the correct primary hot-face material where fibrous insulation is insufficient | Module density does not automatically prove hot-face suitability. A ceramic fiber module and a mullite fiber module may look identical on the outside yet differ in fibre grade, density, and anchor layout. A low-density AES product may be ideal for insulation but unsuitable for direct flame, abrasion, or high gas velocity. Failure Mechanisms: Devitrification, Shrinkage, Creep, and Chemical Attack The real service limits are not the classification temperatures; they are the long-term changes in the material under project conditions. For an overview of all refractory families, see Refractory Insulation Materials: Types, Ratings & Applications. Devitrification Turns Insulation into a Brittle, Dusty Layer Amorphous RCF and AES can devitrify after prolonged high-temperature exposure, forming cristobalite and other crystalline silica species. This increases brittleness, promotes fibre breakage, and changes thermal and mechanical behaviour. The possibility that RCF can form cristobalite is not proof that every installation will do so at the same temperature or rate. Time, temperature, atmosphere, and composition all affect the process. This is why high temperature furnace insulation procurement should require a permanent linear change test under the actual service condition, not merely at a classification temperature. Mullite and PCW Delay, but Do Not Eliminate, Degradation PCW is crystalline rather than glassy and is generally applied above 1300 °C. That does not make it immune to grain growth, strength loss, creep, shrinkage, chemical attack, or mechanical damage. For mullite fiber module and mullite polycrystalline fiber systems above 1300 °C, the specification should require phase and grain analysis, permanent linear change, high-temperature compressive creep or stress-strain data where applicable, thermal-cycling resistance, and chemical exposure data. Alkalis and Halides Can Move the Failure Boundary Below the Nominal Temperature In glass and cement environments, alkali vapour can attack aluminosilicate and mullite materials. In incinerators and some petrochemical heaters, chlorides, fluorides, sulfur, and heavy-metal vapours can create low-melting phases, deposits, or corrosive penetration. AES’s Ca/Mg/Si chemistry should not be assumed to resist these environments better than alumina. The final selection requires either published environment-specific test data, a laboratory crucible or coupon test, or a controlled field trial. Load, Creep, and Anchorage Are Part of the Material Specification A fibre that performs well as a free blanket may fail under compressive load, hanging-module weight, thermal gradient stress, or vibration. For roofs and vertical walls, the anchor material, anchor spacing, cold-face washer, expansion allowance, and module compression are as important as the fibre chemistry. For floors and hearths, fibrous insulation often requires a dense wear course. The material should be selected for the combined temperature and load, not for temperature alone. Procurement Specification and Supplier Evaluation Checklist A generic RFQ requesting “AES” or “high-alumina fibre” invites incompatible offers. A robust procurement specification replaces brand comparison with test-backed data. The minimum fields are listed below. 1. Process and Equipment - Furnace or kiln type - Hot zone and dimensions - New installation or repair - Existing lining and failure history 2. Temperature - Peak and continuous hot-face temperature - Temperature at each interface - Heating and cooling rates - Cycle frequency and duration 3. Atmosphere and Chemistry - Oxidizing, reducing, or mixed atmosphere - Fuel and air/fuel ratio - Alkali, halide, sulfur, metal, or slag species - Condensate, dust, and deposit chemistry 4. Mechanical Duty - Gas velocity - Abrasion or particle impingement - Load and orientation - Vibration and thermal shock 5. Product Requirements - Blanket, board, module, paper, or rigid form - Thickness, density, and dimensions - Fibre orientation and surface treatment - Binder, organic content, and outgassing limits 6. Performance Evidence - Classified, continuous, and allowable service temperatures - Thermal conductivity curve - Permanent linear change - Shrinkage and density after exposure - Compressive creep and modulus data where relevant - Chemical resistance and devitrification data 7. Installation and QA - Anchorage system and spacing - Expansion-joint design - Drawings, installation sequence, and curing procedure - Witness samples and lot traceability 8. Health, Safety, and Compliance - Safety data sheet and jurisdiction-specific classification - Fibre-diameter and biopersistence data where relevant - Personal protective equipment and ventilation requirements - Cutting, removal, and disposal instructions Supplier Comparison Must Use One Validated Test Basis Suppliers should complete a single technical data matrix. Reject comparisons based on incompatible temperature definitions, different test durations, different atmosphere conditions, unspecified shot content, unspecified density, or nominal “use temperatures” without a test basis. The matrix should include chemical composition, phase and microstructure, density and dimensions, temperature-specific thermal conductivity, permanent linear change with time and temperature, binder content and loss on ignition, fibre diameter distribution, shot content, packaging with lot traceability, current safety and transport documents, and the installation warranty scope. Installation, Commissioning, Inspection, and Maintenance Design performance depends on execution. A small but systematic installation defect can cause more damage than a modest difference in nominal fibre grade. Installation Quality Controls the Real Service Temperature Installation should follow the supplier’s current instructions and applicable project safety rules. A robust procedure includes cleaning and inspecting the shell, verifying anchor weld quality and layout, keeping ceramic fiber module layers and blankets dry before installation, maintaining designed compression, offsetting joints, avoiding gaps at kiln lining terminations and penetrations, sealing around burners, thermocouples, tubes, and doors, and recording lifts, serial numbers, and as-built photographs. Pre-Commissioning and Commissioning Should Be Acceptance Milestones Before heating, the purchaser should confirm dimensions and thickness, density, joint alignment, anchor torque or weld integrity, expansion gaps, vapour seals, moisture removal pathway, and compatibility of coatings and adhesives. Commissioning should follow the qualified heating curve. Organic binders should be removed according to the supplier’s instructions. The first heat-up should not be treated as an opportunity to “test the maximum temperature.” Acceptance should include an initial infrared or contact thermal survey where safe, a visual inspection after the first controlled cycle, documentation of any local overheating, measured cold-face temperatures, and confirmation that results are consistent with the design model. Maintenance Should Be Condition-Based and Contamination-Aware Ongoing inspection should record local thinning, shrinkage, cracking, powdering, slag penetration, deposit formation, module loss, anchor exposure, and cold-face hot spots. If the hot-face temperature rises above the design basis, the response should be to recalculate the entire gradient rather than simply adding AES. AES may be appropriate in the cooler backup, but it cannot restore a failed high-temperature face. Bio-Solubility and Occupational Safety: Evidence, Not Marketing AES belongs to a family designed to improve dissolution in physiological fluids relative to conventional RCF. Historical regulatory concepts describe exemptions based on alkaline/alkaline-earth oxide content and demonstrated low biopersistence. This is not a guarantee that every AES product is non-classified or harmless. Fibre diameter, length, dose, durability, and jurisdiction-specific rules can change the conclusion. Dust Control Applies to Every Fibre Family IARC has evaluated man-made vitreous fibres, and crystalline silica is classified as carcinogenic. Heated man-made vitreous fibres can devitrify and form cristobalite. Cutting, drilling, removing, or disturbing any of these materials can create a dust hazard. Procurement should require safety data sheets and local hazard classification, enclosure and extraction, wet methods where compatible, HEPA vacuuming rather than sweeping, personal protective equipment specified by a qualified safety professional, training for installation and demolition personnel, and residue and waste management consistent with the project jurisdiction. Whether the material is called bio soluble ceramic fiber, bio-soluble ceramic fiber, or simply AES wool, cutting, removal, and disturbance can still generate dust. “Bio-soluble” should never be translated into “no controls required.” Decision Framework and Common Specification Mistakes Selection should pass through five gates before a product is named: - Temperature gate: Is the hot face above ~1200 °C, or is there no reliable margin for AES? If yes, assign an alumina, mullite/PCW, or dense high-temperature system to the hot face. - Chemistry gate: Are alkalis, halides, sulfur, slags, or metal vapours present? If yes, require environment-specific testing and do not infer compatibility from the material family. - Mechanics gate: Is there erosion, load, vibration, thermal shock, or high gas velocity? If yes, add a dense or reinforced transition and verify anchorage. - Gradient gate: Has the temperature at the AES surface been modelled and tested? If no, do not place AES adjacent to the hot face. - Lifecycle gate: Is the zone frequently accessed, cut, repaired, or disturbed? If yes, consider bio soluble ceramic fiber or another suitable low-temperature material only in the accessible cooled zone, with a qualified maintenance plan. Red Flags That Should Stop the AES-as-Hot-Face Assumption Red flag | Required action | Hot-face temperature exceeds 1200 °C | Use alumina-family or qualified high-temperature system | No supplier TDS for a 1300 °C claim | Reject as unproven | Alkali, halide, or metal vapour is present | Require chemical compatibility evidence | Only “classified temperature” is provided | Request continuous-service and test data | AES and PCW are treated as interchangeable | Separate chemistry, crystallinity, and product form | Module density is provided without anchor design | Require complete system specification | “Bio-soluble” is used as a safety absolute | Apply SDS and site HSE controls | The Bottom Line for Procurement Teams For ultra-high-temperature service: - Use alumina wool and alumina-family materials for the hot-face, transition, and high-temperature insulation role. - Use AES wool backup insulation for backup, low-temperature zones, personnel-access areas, and selected gasket or expansion-joint applications—only after the local temperature and chemistry are verified. - Where the environment is chemically aggressive or mechanically severe, do not force a fibrous solution. Select dense refractory, zirconia insulation grades such as AZS, or other qualified materials first, then design the insulation system around them. This allocation prevents both under-specification of the hot face and unnecessary over-specification of the entire wall. Procurement teams that enforce this discipline reduce the risk of over-temperature failure, uncontrolled devitrification, incompatible chemical exposure, and unsupported safety claims. Related Reading - High-Temperature Insulation Wool: Temperature Ratings & How to Choose - Polycrystalline Wool Fiber vs Standard Ceramic Fiber - Polycrystalline Fiber Modules: Spec, Installation & Applications - Alumina & Zirconia Ultra-High-Temperature Fiber - Refractory Insulation Materials: Types, Ratings & Applications Review our iron and steel industry insulation applications for furnaces, kilns, and continuous-casting lines in steel and iron production. FAQ: Q: Can AES replace alumina fibre at 1400 °C? A: No, not as a general rule. AES wool is generally applied up to about 1200 °C, while PCW, mullite, and alumina-family systems address zones above 1300 °C. A 1400 °C hot face requires an alumina-family or qualified dense refractory system. Q: Is high-alumina RCF always 52 % Al₂O₃? A: No. The 52 % Al₂O₃ figure is a documented commercial example, not a universal definition. Different producers use different alumina ranges, zirconia additions, impurity limits, and forming routes. Procurement should require a full oxide analysis and the supplier’s grade definition. Q: Is a PCW module the same as a mullite module? A: Not automatically. PCW describes a polycrystalline, normally high-alumina fibre family; mullite refers to a crystalline composition and phase field; a module is a component geometry. The specification must identify fibre chemistry, crystalline phase, forming route, and product form. Q: Is AES bio-soluble, so workers can handle it without controls? A: No. Bio-solubility relates to composition and biopersistence, but cutting, removal, and disturbance can still generate respirable dust. Site controls, PPE, ventilation, and waste management remain necessary. Q: Does a 1600 °C classification mean the material can carry 1600 °C continuously? A: Not without the supplier’s qualified continuous-service evidence. Atmosphere, loading, time, chemical exposure, and installation conditions must all be considered. Classification temperature, reheat temperature, and continuous service temperature are not interchangeable. Q: Can AES be used in a glass furnace? A: Only in a cooler, protected backup zone after alkali-vapour and interface-temperature verification. It should not replace the hot-face refractory exposed to aggressive glass-furnace chemistry. Q: What is the single most important field in the RFQ? A: The combination of hot-face temperature and atmosphere. Neither alone is sufficient. A high-temperature, chemically aggressive atmosphere may require a different system from a clean, oxidizing furnace at the same nominal temperature. ### Refinery & Reformer Insulation: A Unit-by-Unit Guide URL: https://www.rosetexwool.net/news/refinery-reformer-insulation-types/ 2026-09-14 | Author: Rosetexwool Editorial | Category: industry insight Summary: Unit-by-unit refinery insulation engineering: classification vs continuous use temperature, hot-wall and cold-wall reformers, coker thermal cycling, SRU dew points, and the offshore constraint layer. Choosing refinery insulation is not a matter of picking a material off a single temperature chart. A crude distillation column, an FCC regenerator, a delayed coker drum and a catalytic reformer furnace all run in different temperature bands, carry different process media and fail in different ways. A system that performs for years on a steam main can shrink, crack or corrode within one operating cycle on a coker drum. This guide walks through the refinery unit by unit, explains the engineering logic behind each insulation decision, and closes with the constraints that reshape offshore refinery insulation when the plant moves onto a platform. Classification Temperature vs Continuous Use Temperature The single most common specification error in high-temperature refinery insulation is confusing classification temperature with continuous use temperature. The classification temperature is a laboratory value: the temperature at which a material shows no more than a defined permanent linear shrinkage — typically 3–4 % after 24 hours — under ideal conditions. It is not the temperature at which the material can operate for years. For refractory ceramic fiber, the practical margin between the two is typically 150–200 °C. A standard 1260 °C classification grade is recommended for continuous service only up to roughly 1050–1100 °C in clean oxidizing atmospheres. Zirconia grades classified at 1430 °C are rated for continuous use around 1300–1350 °C. Designing a lining to its classification temperature instead of its continuous use temperature is a leading cause of premature shrinkage, joint openings and hot spots in refinery furnaces. Material | Classification / grade | Continuous use | Typical forms | Ceramic fiber, standard | 1260 °C | ~1050–1100 °C | Blanket, module, board | Ceramic fiber, high-alumina | 1400 °C | ~1200 °C | Module, board | Ceramic fiber, zirconia | 1430 °C | ~1300–1350 °C | Blanket, module | Rock wool | — | ~650 °C | Board, blanket, pipe section | Calcium silicate, Type I (ASTM C533) | — | ~650 °C | Block, pipe covering | Calcium silicate, high-temp (ASTM C533 Type II basis) | — | ~1000 °C | Block | Glass wool | — | ~250 °C | Blanket, board | Aerogel blanket | — | −200 to +650 °C | Flexible blanket | Keep this table within reach through the rest of the article: every unit below draws on it, and every grade above is quoted at its continuous use temperature, not its classification. Crude and Vacuum Distillation: 150–420 °C and the Vacuum Sealing Problem The crude distillation unit and vacuum distillation unit anchor the warm end of refinery insulation. Atmospheric columns operate from about 150 °C at the top to 420 °C at the bottom, with vacuum columns showing similar metal temperatures under sub-atmospheric pressure. For most columns, rock wool board or calcium silicate sections with aluminum or stainless-steel jacketing are standard, and rock wool pipe sections carry the surrounding transfer lines. Two details separate this unit from ordinary warm service: - Vacuum sealing. Any air in-leakage through poorly sealed jacketing joints can degrade vacuum performance and drive internal oxidation. On a vacuum column, the outer cladding is part of the process system, not just weather protection. - Personnel protection governs thickness. In the cooler upper sections, insulation thickness is often set by the touch-temperature limit — keeping the outer surface at or below about 60 °C — rather than by heat loss economics. For the wider context of how these units fit into a full plant specification, see our petrochemical plant insulation guide. Fluid Catalytic Cracking: Erosion and the 730 °C Regenerator The FCC unit is the most mechanically abusive environment in the refinery. Riser and reactor outlets run at 510–565 °C, while the regenerator dense bed sits at 650–730 °C, with dilute-phase and catalyst-cooler zones reaching 760 °C or higher. The insulation strategy is layered from the inside out: - Reactor and regenerator vessels carry an internal refractory lining — abrasion-resistant castable anchored to the shell — because catalyst fines erode any unprotected surface. Behind it sits an insulating castable or ceramic fiber module layer, with external insulation only where shell temperatures still require it. - Cyclones and standpipes rely on refractory-lined systems for the same erosion reason. - The main fractionator splits by temperature: a lined lower section with external rock wool or calcium silicate, and a cooler upper section where lighter materials are acceptable. Two constraints matter for the insulation engineer. First, the reactor–regenerator pair expands thermally by different amounts, so expansion joints in both refractory and insulation are mandatory, not optional. Second, catalyst fines that penetrate a damaged jacket create hot spots and feed corrosion under insulation on the shell beneath — the same CUI mechanism found elsewhere in the plant, but accelerated by abrasive, heat-carrying particles. Hydrotreaters and Hydrocrackers: Designing Around Hydrogen Hydrotreating and hydrocracking reactors operate at 260–430 °C depending on feedstock — VGO units around 360–380 °C, residue units up to 400–440 °C — under high hydrogen partial pressure. Metallurgy, not insulation, is the star of this unit: reactor peak temperatures are limited to roughly 427 °C by the steel itself. Insulation still matters in three specific ways: - HTHA risk assessment. For piping above about 204 °C in high-pressure hydrogen service, material selection must respect the Nelson curves in API RP 941, which define where carbon and low-alloy steels become vulnerable to high-temperature hydrogen attack. Insulation does not change the metallurgy, but it determines the metal temperature profile that the curve analysis depends on. - Temperature excursions. Hydrocracking is strongly exothermic, and a runaway can push wall temperatures far above design in minutes. The insulation system must tolerate rapid, unplanned spikes without melting, shrinking or slumping. - Quench zones. Multiple catalyst beds with quench-gas injection create internal temperature steps; the external insulation design must follow these zones so no surface point becomes a personnel-protection problem. Refinery insulation on this unit follows the metallurgy, not the other way round. In practice, hot reactors and high-pressure loops use calcium silicate or rock wool with stainless-steel jacketing, selected so the system neither traps hydrogen against the wall nor holds moisture there. Catalytic Reformers: Hot-Wall vs Cold-Wall Logic The catalytic reformer is where insulation design meets reactor metallurgy head-on. Reactor inlet temperatures run around 450–520 °C and outlets 500–550 °C, and the industry builds two completely different vessel philosophies to handle this. Cold-wall reactors protect a carbon-steel pressure boundary with an internal refractory lining, often backed by insulating material and an internal metal liner. The shell stays below about 343 °C — comfortably within carbon-steel creep limits. The primary insulation is on the inside; the outside may need only light insulation for personnel protection. Semi-regenerative units have traditionally favored this design. Its weakness is degradation: if the internal lining develops hot spots, the shell can creep toward its limits (the creep transition for common vessel carbons sits near 399 °C), and external air cooling becomes an emergency measure. Hot-wall reactors make the shell from Cr-Mo alloy steel — typically 1.25Cr-0.5Mo, or 2.25Cr-1Mo above 538 °C — and insulate it externally. The shell runs at or near process temperature, so external reformer insulation must limit heat loss, keep surfaces safe to touch, and avoid introducing moisture that would attack the alloy. Continuous catalytic regeneration (CCR) units use hot-wall reactors almost exclusively, either as individual vessels or stacked in one compartmented shell. Whether a given reactor is hot-wall or cold-wall decides where the reformer insulation sits, what material it is made of, and which failure mode will end its service life. Reformer insulation also faces a chemical quirk: traces of HCl from catalyst regeneration can migrate to cooler zones and condense as acid. Reformer insulation in these transition zones must keep metal temperatures above the acid dew point — the same logic the sulfur unit below follows in its most extreme form. For what these furnaces look like from the inside, see our reformer furnace reline case study. Reformer Furnaces and Hydrogen Plants: The Zones Above 900 °C Whatever the reactor wall philosophy, the fired heater that feeds it runs hotter than anything else in the unit. The radiation section of a refinery furnace operates at 900–1300 °C, which places it firmly in ceramic-fiber territory — this is the heart of refinery furnace insulation: ceramic fiber modules of 1260 °C or 1400 °C grade on walls and roofs, castable refractory with anchors on floors and burner quarls, and backup insulation behind the hot face to hold shell temperatures down. Steam methane reformers in hydrogen plants push this further. Reformer tubes exit at 820–950 °C, tube skin temperatures approach 980 °C, and the transfer pigtails and manifolds need high-nickel alloys to survive. External insulation on this piping is typically ceramic fiber blanket or modules, and personnel protection becomes a primary design driver — few places in the plant are less forgiving of a thin or damaged jacket. The convection section, where flue gas cools to 400–650 °C, transitions back to rock wool or calcium silicate on ducting and waste-heat coils. Getting this transition right — ceramic where the gas is hot, mineral wool where it is not — is what separates refinery furnace insulation that lasts from insulation that cooks. Delayed Cokers: Heat, Water and Mechanical Abuse The delayed coker drum may be the hardest vessel in the refinery to insulate well. Feed enters at 460–500 °C, and every 12–24 hour cycle ends with the drum quenched with water to near ambient before coke is cut out with high-pressure jets. Heat, water and mechanical abuse — the three enemies of any insulation system — arrive in the same shift, and a blanket chosen by classification temperature alone will not survive its first year. Traditional fibrous insulation struggles here: binder-containing blankets age rapidly above their binder burnout limits during the heating phase, then soak up quench water during the cooling phase, setting up severe corrosion under insulation — a point our companion article on rock wool in refining develops further. Modern practice therefore favors: - Flexible, binder-free systems — ceramic fiber blanket or aerogel blanket — that tolerate thermal shock and dry out without structural damage. - Robust metal jacketing with sealed seams, because hydraulic decoking guarantees water exposure. - Removable insulation covers on manways and top and bottom heads, which see frequent inspection. Thermal fatigue is the structural counterpart: the skirt-to-cone junction is a well-known cracking location, and any rigid insulation that restrains shell movement accelerates the damage. Flexible systems with expansion provisions are the default recommendation. Sulfur Recovery: When Insulation Thickness Controls Corrosion The Claus sulfur recovery unit spans the widest temperature range of any refinery unit: the thermal reactor burns at 1000–1400 °C behind dense refractory, catalytic reactors run at 250–350 °C, and condensers sit at 130–160 °C. Refinery insulation on this unit is not primarily an energy decision — it is a corrosion-control decision. Two dew points govern everything: - Sulfur dew point. Process gas in the catalytic stages must stay at least about 17 °C above the sulfur dew point, or liquid sulfur condenses in the catalyst pores and deactivates the bed. Undersized insulation on a reactor outlet can quietly kill conversion. - Acid dew point. In tail-gas sections, SO₃ and water vapor can raise the acid dew point to as high as 177 °C. If insulation on tail-gas piping or waste-heat equipment lets the wall fall below this, concentrated sulfuric acid condenses on the metal and corrosion becomes rapid and visible within months. The countermeasure is calculated insulation thickness — sometimes deliberately combined with steam tracing — so the wall temperature sits safely above both thresholds. Calcium silicate pipe insulation with stainless jacketing is the workhorse here, chosen precisely because its compressive strength and known thermal performance keep wall temperatures predictable over years. Amine Units and Flare Stacks: The Quiet Extremes Two units sit at the edges of the refinery insulation map and are easy to get wrong by over- or under-thinking them. Amine treating is thermally simple — absorbers at 40–65 °C, regenerators at 120–130 °C, reboilers at 150–175 °C — and glass wool board or rock wool blanket covers most of it. The watch item is wet insulation: amine degradation products cause localized internal corrosion, and if the insulation system also allows external corrosion, wall loss accelerates from two directions at once. CUI prevention, not temperature rating, is the real specification task. Flare stacks face the opposite profile in refinery insulation terms: intermittent service, flame temperatures above 1200 °C, and radiant heating of a structure that may sit cold and rain-soaked for months. The lower radiant section typically carries refractory lining; upper sections may need only ceramic fiber blanket where wall temperatures demand it. The dominant failure mode is thermal shock — sudden ignition of a cold, wet stack cracks rigid refractory — so the lining system must be detailed for rapid heating, not just peak temperature. Offshore Refinery Insulation: The Extra Constraint Layer Everything above applies to an onshore refinery. An offshore platform keeps every one of those requirements and adds a layer of its own, which is why offshore refinery insulation deserves its own specification logic rather than a footnote. - Marine atmosphere. Salt spray destroys bare aluminum jacketing through pitting and galvanic attack, so offshore specifications call for stainless-steel or coated-aluminum cladding — commonly a 0.5 mm stainless minimum in exposed areas under NORSOK M-004 (the current designation of the former R-004), the governing North Sea standard for thermal, acoustic and fire insulation on topsides. - Weight limits. Deck loading is budgeted in kilograms per square metre, and thick dense insulation on large bore piping consumes that budget fast. The permissible thickness may be set by structural engineers, not thermal calculations — which is exactly where lightweight aerogel blanket earns its keep, delivering high thermal resistance at a fraction of the weight of rigid materials. - Fire ratings. Offshore design distinguishes hydrocarbon pool fire ratings (H-ratings) from jet fire ratings (J-ratings) under the project fire-response strategy, aligned with ISO 13702. Thermal insulation and passive fire protection are separate duties: process piping in fire zones may need PFP wrap over insulation, emergency shutdown valves need dedicated fire-rated jackets, and structural steel under pressurized equipment needs PFP regardless of process temperature. - Amplified CUI. Constant humidity, salt-laden air, daily temperature cycling and cramped inspection access make corrosion under insulation the dominant maintenance cost offshore — our companion guide to marine and offshore fire insulation standards covers the material side. API RP 583 frames the management program: hydrophobic insulation materials, sealed jacketing seams, drain points at low spots, and inspection priority on systems whose operating temperature cycles through the CUI-critical band, roughly −4 to +121 °C. - Modular construction. Topsides are insulated onshore as modules, transported by barge and lifted into place. The insulation must survive transport loads, salt exposure and partial removal for weld inspection — which strongly favors removable covers and blanket systems over rigid sections that shatter when disturbed. When Insulation Fails: Dew Points, Cycling and Access Step back from the unit list and three failure families explain most refinery insulation problems. Dew-point failures are the quiet ones. Whether it is sulfuric acid on SRU tail gas, HCl near a reformer regeneration loop, or plain condensation under a jacket, the mechanism is the same: a wall temperature allowed to fall below a local dew point. The fix is rarely "more insulation" — it is correctly calculated insulation, sometimes with tracing, that holds the wall above the threshold. Cycling failures are the mechanical ones. Coker drums, regenerators and transfer lines expand and contract daily; rigid materials crack, anchors fatigue, and joints open. Flexible blanket systems with expansion provisions tolerate this movement, which is why they dominate cycling service — provided their continuous use temperature genuinely covers the peak, not just the nameplate grade. Access failures are economic. Valves, flanges, manways, turbines and compressors need regular attention, and permanent insulation destroyed at each turnaround becomes a recurring cost. Removable insulation covers — flexible jackets with straps or fasteners — survive multiple turnaround cycles, cut critical-path downtime and open the surface for inspection without cutting metal. With refinery turnarounds running every 3–6 years, and offshore man-hour rates at their premium, removable covers frequently pay back within a single maintenance cycle. Material Temperature Limits at a Glance The table below consolidates the working limits used throughout this guide. Densities are typical commercial ranges; thermal conductivity varies with mean temperature, so economic-thickness calculations should always use manufacturer k-value curves rather than single-point values. When a datasheet is ambiguous, ask the supplier to state the continuous use temperature at your design conditions, in writing. Material | Continuous service | Typical density | Refinery roles | Glass wool | ~250 °C | 10–48 kg/m³ | Low-temp piping, amine units, acoustics | Rock wool board / blanket | ~650 °C | 80–200 kg/m³ | Vessels, columns, furnace backup | Rock wool pipe sections | ~650 °C | 120–180 kg/m³ | Process piping, steam mains | Calcium silicate, Type I | ~650 °C | 170–240 kg/m³ | Hot piping, reboilers, SRU service | Calcium silicate, high-temp | ~1000 °C | 200–270 kg/m³ | Furnace-adjacent equipment | Ceramic fiber blanket (1260 grade) | ~1050–1100 °C | 64–160 kg/m³ | Furnace linings, reformer backup | Ceramic fiber module (1400 grade) | ~1200 °C | 200–320 kg/m³ | Furnace roofs and walls | Ceramic fiber, zirconia (1430 grade) | ~1300–1350 °C | 128–160 kg/m³ | Hottest furnace zones | Aerogel blanket | −200 to +650 °C | 180–220 kg/m³ | CUI mitigation, weight-limited offshore work | Cellular glass | −260 to +400 °C | 110–150 kg/m³ | Cryogenic and low-temp hydrocarbon service | Specifying Refinery Insulation: What to Put in an Enquiry Most specification errors we see trace back to information that was missing at enquiry stage, not to the material choice itself. A complete refinery insulation enquiry states: - The unit and the service — "hydrotreater reactor loop, 410 °C, high-pressure hydrogen" tells us more than a bare temperature. - Design and operating temperatures, including excursion expectations for cycling units. - Line sizes and geometry, since standard bore sizes take preformed sections while large or irregular geometry takes blankets — the construction-level question of refinery insulation types is covered separately in our industrial pipe insulation types guide. - Ambient and jacketing requirements — indoor, coastal, or full offshore refinery insulation service with stainless cladding. - CUI policy — hydrophobic materials, sealed seams, drain details. - Access points — valves, instruments and manways that justify removable insulation covers. - Applicable standards — ASTM material standards, API recommended practices, and project fire strategy. Send those seven lines and the material shortlist effectively writes itself. Where a unit sits above 1000 °C, the answer will start with ceramic fiber; between 250 and 650 °C it will start with rock wool and calcium silicate; below 250 °C, glass wool and aerogel take over. The unit-by-unit logic above is what turns those bands into a specification that survives its first turnaround. Explore our petrochemical plant insulation applications for reformers, crackers, and pipe racks in refining and petrochemicals. FAQ: Q: What is the difference between classification temperature and continuous use temperature? A: Classification temperature is a laboratory rating: the temperature at which a material shows no more than a defined permanent linear shrinkage, typically 3–4 % after 24 hours. Continuous use temperature is what the material can withstand for years in service. For ceramic fiber the practical margin between the two is 150–200 °C — a 1260 °C classification grade is good for roughly 1050–1100 °C continuous in clean oxidizing atmospheres. Specifying to the classification figure instead of the continuous use temperature is the most common cause of premature lining shrinkage and hot spots. Q: Why do catalytic reformer reactors come in hot-wall and cold-wall designs? A: A cold-wall reactor protects a carbon-steel shell with an internal refractory lining, keeping the metal below about 343 °C; the insulation lives on the inside, and the shell needs only light external cover. A hot-wall reactor is made from Cr-Mo alloy and runs at process temperature, so it is insulated externally like any hot pipe. Semi-regenerative units have traditionally used cold-wall vessels, while continuous catalytic regeneration (CCR) units are invariably hot-wall. The choice decides where the insulation sits, what material it is made of, and which failure mode will end its service life. Q: What insulation survives a delayed coker drum? A: Coker drums cycle from about 460–500 °C down to a water quench every 12–24 hours, so the insulation sees heat, water and mechanical abuse in the same shift. Flexible, binder-free systems — ceramic fiber blanket or aerogel blanket — tolerate the thermal shock and dry out without structural damage, protected by well-sealed metal jacketing against quench water. Rigid materials crack under the cycling, and any system that restrains shell movement accelerates the known fatigue cracking at the skirt-to-cone junction. Removable covers on manways and heads handle the frequent inspection access. Q: Why does insulation thickness control corrosion in a sulfur recovery unit? A: Because two dew points govern the unit. In the catalytic stages, process gas must stay at least about 17 °C above the sulfur dew point or liquid sulfur condenses in the catalyst pores and deactivates the bed. In tail-gas sections, SO₃ and water can raise the acid dew point to as high as 177 °C — if the wall temperature falls below that, concentrated sulfuric acid condenses on the metal and corrosion becomes rapid. Correctly calculated insulation thickness, sometimes with steam tracing, is what holds wall temperatures above both thresholds; 'more insulation' is not automatically the answer. Q: What is different about offshore refinery insulation? A: An offshore platform keeps every onshore requirement and adds its own layer. Salt spray rules out bare aluminum jacketing in favour of stainless or coated aluminum, commonly 0.5 mm stainless minimum under NORSOK M-004. Deck loading in kilograms per square metre can cap insulation thickness regardless of the thermal calculation, which favors lightweight aerogel blanket. Fire strategy adds hydrocarbon pool-fire and jet-fire ratings on top of thermal duty. Humidity, salt and temperature cycling amplify corrosion under insulation, and modular construction favors removable, blanket-based systems that survive transport and partial removal for weld inspection. Q: Which insulation should I use for refinery piping at around 600 °C? A: At 600 °C the natural starting point is rock wool pipe sections or calcium silicate, both rated for continuous service at about 650 °C. Rock wool sections at 120–180 kg/m³ are the standard answer for process piping and steam mains; calcium silicate brings higher compressive strength where jacketing loads or foot traffic demand it. The material must be paired with the right jacketing and sealed seams, because at this temperature a wet insulation system is simultaneously a heat-loss problem and a corrosion problem. Above roughly 650 °C the answer moves to ceramic fiber products. Q: How often should refinery insulation systems be inspected? A: Inspection should follow the operating temperature, not the calendar alone. Systems cycling through the corrosion-under-insulation critical band — roughly −4 to +121 °C, peaking around 60–80 °C where condensation is most active — deserve priority inspection at every opportunity, as framed by API RP 583. jacketed systems on dew-point-critical service such as SRU tail gas need wall-temperature verification whenever the unit is opened. Between turnarounds, which typically run every 3–6 years, thermography and jacketing seam surveys catch damaged cladding before it becomes a CUI repair job. ### Insulation Board & Panel Forms: Board, Panel, Tile and Sheet Compared URL: https://www.rosetexwool.net/news/insulation-board-panel-forms-selection-guide/ 2026-09-13 | Author: Rosetexwool Editorial | Category: industry insight Summary: Board, panel, tile and sheet are form words, not material words. This guide fixes each term, then compares the five insulation board families by temperature, density and cost. Quick answer: Board, panel, tile and sheet are form words, not material words. In industrial insulation, board is the default term for an insulation board: a rigid, self-supporting flat slab from roughly 12 mm to 150 mm thick, and it is the safest word to use in an enquiry when nothing else has been specified. Panel implies a larger format or a composite assembly such as a sandwich panel or a vacuum insulation panel. Tile belongs almost exclusively to insulating firebrick and masonry linings. Sheet describes anything thin enough — usually under 12 mm — that it will not stand on its own, such as ceramic fiber paper or a light glass wool facing. Procurement teams lose weeks to this vocabulary. A drawing that says "insulation panel" can come back quoted as a board, as a metal-faced sandwich assembly, or as a vacuum panel, and the three differ in price by an order of magnitude. This guide fixes each form term the way the industrial insulation trade actually uses them, then places the five insulation board families — calcium silicate, rock wool, glass wool, ceramic fiber and the nano-porous group — against the temperature, density and cost decisions that drive a real specification. The range runs from commodity building board to high temperature insulation panels for furnace linings, and the vocabulary changes as you move along it. Why Form Terms Decide What You Actually Receive Form words carry three pieces of information that material words do not: how the product is made, how it is installed, and how it is priced. A vacuum-formed ceramic fiber board is produced on a suction mould from a fibre slurry, dried and cut to size, which is why it arrives rigid and machinable. The same fibre in blanket form is needled into a roll and sold by the square metre at a fraction of the price. Ask for the wrong form and you will either pay for rigidity you do not need or receive a product that cannot carry its own weight in the position you planned. Form also sets the price basis. Board and tile are quoted by area at a stated thickness, sometimes by piece count. Thermal insulation sheet and paper are frequently quoted by the roll or by weight. Sandwich panels are quoted by area but priced as a system, because the facing is part of the cost. When two quotations look wildly different for what appears to be the same product, the form word is the first thing to check. Form is the first line of any insulation board specification; material and grade follow it. Board: The Default Rigid Form Board is the single most useful word in industrial insulation procurement. It means a rigid or semi-rigid flat slab with enough stiffness to be handled, cut, drilled and fixed without a backing substrate. Typical thickness runs from 12 mm to 100 mm for most materials, with calcium silicate reaching 150 mm in layered back-up insulation and high temperature insulation panels available from about 6 mm. Common formats are 600 × 1200 mm, 1000 × 1200 mm and 1200 × 2400 mm, with 600 × 900 mm usual for vacuum-formed ceramic fibre products. Densities span a wide range because the word says nothing about material: 24 kg/m³ for a light glass wool board, 280 kg/m³ for a standard calcium silicate board, 320 kg/m³ for a vacuum-formed ceramic fiber board. Because board is machinable, it is the form specified where the insulation has to accept fixings — anchors, studs, thermocouple penetrations, or a bolted hot-face. It is also the form chosen when the insulation is part of a structural build-up rather than a wrap: boiler casings, furnace back-up layers, fire-rated partitions and equipment bases. If nothing else has been agreed, "board" is the word to put on the insulation board enquiry. Panel: Larger, Composite or System-Built Panel overlaps with board, and in some product families the two are used interchangeably. The difference is emphasis: panel suggests a larger format, a composite build-up, or a product that is installed as a system rather than as a piece of material. Three cases make the distinction worth keeping: - Sandwich panel — a rock wool or mineral wool core bonded between two metal faces, used for building envelopes, cold stores and industrial partitions. This is the most common industrial use of the word, and rock wool sandwich panel is a fixed trade term. - Duct panel — glass wool board supplied with a factory-bonded facing for HVAC ductwork, cut and folded into a duct on site. - Vacuum insulation panel — a flat evacuated core sealed in a barrier film. The industry always says panel here, never board, and the reason is structural: the product is a sealed system that fails if punctured, not a piece of material. Where a supplier uses panel and board as synonyms for the same insulation board, the format and fixing detail on the data sheet will tell you which behaviour to expect. Tile and Sheet: The Two Edge Cases Tile is the least useful of the four words and the most frequently misused. In practice it describes small rectangular units laid course by course, which means insulating firebrick — the 230 × 114 × 65 mm format is the standard reference — and the refractory tiles used to line flues, burners and hearths. If a buyer contacts an insulation tiles manufacturer asking for calcium silicate tile or ceramic fiber tile, the answer will almost always come back quoted as board, because that is what the material is sold as. Reserving tile for genuine masonry units avoids a round of clarification on every enquiry. Sheet is the thin end of the insulation board range, and thermal insulation sheet is sold very differently from board. A sheet is semi-flexible to flexible, typically under 12 mm, and usually cut from a roll or a felt rather than formed as a discrete slab. Ceramic fiber paper and ceramic fiber sheet are effectively the same product at 1–6 mm, used for gaskets, parting layers and expansion joints. Most thermal insulation sheet suppliers quote by the roll or by weight rather than by the square metre. Thin glass wool sheet turns up as facings and acoustic liners. Calcium silicate is occasionally called sheet below 6 mm, though more than nine times out of ten it is still sold as board. The practical boundary between the two words: below about 6 mm, or anything that cannot stand on edge, is a sheet. Above 12 mm with self-supporting stiffness, it is an insulation board by any trade definition. Between 6 and 12 mm, use whatever the data sheet says. The Four Forms at a Glance Form | Core characteristic | Thickness range | Self-supporting | Typical use | Board | Rigid flat slab, machinable | 12–150 mm | Yes | Furnace back-up, boiler casing, fire board, equipment bases | Panel | Large format or composite assembly | 20–200 mm | Yes | Sandwich panel, duct panel, vacuum insulation panel | Tile | Small masonry unit | 25–75 mm | Yes | Insulating firebrick linings, hearths, flues | Sheet | Thin, semi-flexible, cut from rolls | 1–12 mm | No | Gaskets, parting layers, facings, acoustic liners | Calcium Silicate: Rigid Back-Up to 1000 °C Calcium silicate board is the rigid workhorse of the 650–1000 °C band. It is non-asbestos, light grey to white, supplied at 220–400 kg/m³ in insulation grades, and it carries compressive strength an order of magnitude above any fibre board — which is why it sits behind refractory linings and under boiler casings rather than competing with them. Thermal conductivity sits near 0.06 W/(m·K) at ambient and rises with mean temperature, as it does for every insulation material. In practice, calcium silicate thermal insulation is specified by continuous service temperature first — 650 °C for general industrial work, 1000 °C where the lining runs hotter — and only then by thickness. The properties that actually drive specification are dimensional stability at temperature, low shrinkage, and the ability to be cut and drilled on site without friable edges. Calcium silicate thermal insulation is also the usual answer where a fire-rated board is needed in an industrial setting, because it is non-combustible and holds its shape under direct flame far better than a fibre product. The limitations of calcium silicate thermal insulation are equally clear. It absorbs water and loses strength when saturated, so outdoor and below-grade work needs a weather barrier designed in from the start. And it is heavy relative to other insulation board families, which matters on large vertical surfaces. For the full property set and grade-by-grade figures, see our high density calcium silicate board guide; the product range is on calcium silicate insulation board. Rock Wool and Stone Wool: Boards, Slabs and Sandwich Panels Rock wool — also sold as stone wool and, in European documentation, as mineral wool board or slab — covers the 40–200 kg/m³ density range with thermal conductivity around 0.034–0.040 W/(m·K) at ambient. In board form, rock wool thermal insulation is supplied as slab or board, and thermal grades normally start at 80 kg/m³ and run to 200 kg/m³ where compressive strength or acoustic performance is specified. Rock wool thermal insulation is continuous-rated to about 650 °C on industrial grades, with lower-rated building grades at 250 °C and below. Below 250 °C, rock wool thermal insulation competes directly with glass wool on price per square metre and wins where fire performance or compressive strength is part of the specification. It is the default choice for exterior wall insulation, roof decks, industrial ovens, and any application where fire performance and acoustic absorption are wanted from the same layer. Non-combustibility to A1 means it also does duty as a fire break in curtain walling and service risers. In panel form, rock wool becomes the core of a sandwich panel: a bonded assembly with metal faces that is installed as a building envelope element rather than as insulation. That changes the specification entirely — core density, facing gauge, panel length and fixing detail all matter, and the acoustic and fire performance of the assembly is tested as a system. Glass Wool Board for HVAC and Building Envelopes Glass wool board is the lightest of the five families and the cheapest per square metre at a given thickness. Standard board densities run from 24 to 48 kg/m³, with high-density acoustic grades reaching about 100 kg/m³. Thermal conductivity is around 0.030–0.035 W/(m·K) at ambient, so on pure thermal performance at low temperature it beats the heavier fibre boards. The limit is temperature. Most glass wool boards run 250 °C continuous on the standard grade and 538 °C continuous on high-temperature grades, with peak exposures 100–200 °C above those figures for short periods. Above that, the binder is the constraint, not the glass. Within its band, glass wool board dominates HVAC: duct board and duct panel, ceiling board, suspended acoustic ceilings, and foil-faced boards for plant rooms. Because glass wool board is semi-rigid, it is normally supported in a framework or bonded to a substrate rather than spanning on its own. Where the same project needs a rigid self-supporting board for a warmer line, rock wool or calcium silicate takes over. Our rigid glass wool board selection guide covers the density and facing decisions in detail; the product line is at glass wool board. High Temperature Insulation Panels: Ceramic Fiber and Beyond Above roughly 1000 °C, the choice narrows to ceramic fiber board and its higher-temperature relatives. A high temperature ceramic fiber board is vacuum-formed from aluminosilicate fibre with an inorganic binder, typically at 280–320 kg/m³, and graded by classification temperature: 1260 °C standard, 1400 °C high-purity, 1450 °C zirconia-bearing. Continuous service sits below the classification figure, and the gap between the two is where most specification mistakes are made. Thermal conductivity near ambient is roughly 0.08–0.12 W/(m·K) and rises with mean temperature, so a ceramic fiber board is not a high-efficiency insulator at low temperature — it is specified because nothing else survives. Where thermal shock is the governing risk, a high temperature ceramic fiber board also outperforms every rigid alternative, because the fibre structure absorbs the movement that cracks a dense refractory board. Where it is used: furnace hot face and back-up layers, door linings, launder and trough covers, heat shields, and any place where thermal shock resistance matters more than the conductivity figure. High temperature insulation panels also cover the polycrystalline and mullite grades that extend the range to 1600 °C and beyond, at considerably higher cost, and the bio-soluble fibre boards used where worker exposure limits rule out conventional refractory ceramic fibre. Our polycrystalline mullite board guide covers the top of that range. For the thin end of the same family — paper, sheet and gasket material — see the ceramic fiber rope, tape, cloth and paper buying guide. Vacuum-formed board is stocked on ceramic fiber board. Microporous Board, Aerogel Board and Vacuum Insulation Panels The nano-porous group exists to solve thickness problems, and it is priced accordingly. Microporous insulation board reaches 0.020–0.025 W/(m·K) at ambient — below still air, because the pore structure is finer than the mean free path of the gas molecules inside it. Service temperatures run to 900–1200 °C at 200–350 kg/m³. It is the standard answer where a furnace lining has to be thinner than conventional board allows, and it appears in appliance and foundry work far more often than its cost would suggest. Aerogel board takes the same logic into the 600–650 °C band in rigid form, with thermal insulation sheet grades down to a few millimetres, alongside the flexible aerogel blanket that dominates pipe work. Thin aerogel board is common in transportation, battery enclosures and equipment skids where every millimetre counts. Vacuum insulation panel is the extreme case: 0.004–0.007 W/(m·K), five to ten times better than a conventional board, in 10–30 mm. The trade is fragility and life. A puncture destroys the vacuum instantly, panels cannot be cut on site, and barrier permeation means performance declines over a service life generally quoted at 20–25 years. VIP is the right answer for refrigerated containers, cold-chain packaging and space-constrained building retrofits, and the wrong answer for anything that will be drilled, walked on or maintained without protection. Cross-Material Comparison: Conductivity, Density, Temperature, Cost Property | Calcium silicate board | Rock wool board | Glass wool board | Microporous board | Ceramic fiber board | Density kg/m³ | 220–400 | 40–200 | 24–100 | 200–350 | 160–600 | Thermal conductivity, ambient W/(m·K) | ~0.06 | 0.034–0.040 | 0.030–0.035 | 0.020–0.025 | 0.08–0.12 | Maximum service temperature °C | 650–1000 | up to 650 | 250 standard, 538 high-temperature | 900–1200 | 1050–1450 by grade | Compressive strength | High, MPa range | Low to moderate | Low | Moderate | Moderate | Water behaviour | Absorbs, loses strength when wet | Hydrophobic when treated | Hydrophobic when treated | Needs a facing | Absorbs, can shrink | Reaction to fire | A1 non-combustible | A1 non-combustible | A1 non-combustible | A1 non-combustible | A1 non-combustible | Relative cost | Medium | Low | Lowest | High | Medium to high | These are typical industry values for comparison only; the data sheet for the specific grade governs any purchase. Selecting by Temperature, Budget and Available Space Temperature is the first filter in insulation board selection, because it rules materials out rather than ranking them. Service band | First choice | Also works | Wrong choice | Up to 250 °C | Glass wool board | Rock wool board | Ceramic fiber (over-specified), calcium silicate (overweight) | 250–450 °C | Rock wool board at the high-temperature grade | High-temperature glass wool | Microporous (cost) | 450–650 °C | Rock wool board at 650 °C grade, or calcium silicate board | Calcium silicate board | Glass wool (over temperature) | 650–1000 °C | Calcium silicate board, with ceramic fiber board on the hot face | Microporous board for thin sections | Rock wool, glass wool | 1000–1400 °C | High temperature ceramic fiber board at 1260–1400 °C grade | Polycrystalline board | Calcium silicate (at its limit) | Above 1400 °C | Zirconia-bearing or polycrystalline grades | Alumina fiber board | Everything else | Budget narrows the result within each band: glass wool and rock wool for building and HVAC work, calcium silicate and rock wool for industrial plant up to 650 °C, a high temperature ceramic fiber board with a calcium silicate back-up layer above 1000 °C, and the nano-porous group only where the thickness saving pays for itself in space, weight or energy. Above 1000 °C the answer is always a high temperature insulation panel of one kind or another — ceramic fiber board, or its polycrystalline and mullite relatives at the top of the range. Available space can reverse the whole insulation board analysis. Where the available thickness is 20 mm or less, conventional board cannot meet the duty at all and a vacuum insulation panel or aerogel product is the only option. Between 20 and 50 mm, microporous board typically saves a third of the thickness of a conventional build-up. Above 100 mm, the cheap low-temperature boards win on economics every time. What an Insulation Board Supplier Needs From Your Enquiry The supplier directory approach is less useful than it looks, because insulation board supply is localised and lead times dominate. What actually shortens the quotation cycle is a complete specification in the first email. Every item below changes the price: - Material and grade — including the classification temperature for high temperature insulation panels, and whether a non-asbestos grade is required for calcium silicate - Density — quoted in kg/m³, not "standard" or "high density" - Thickness and tolerance — and whether the thickness quoted for the insulation board is nominal or minimum - Board size and edge profile — square cut, tongued and grooved, or shiplap - Facing — foil, glass tissue or unfaced, and whether thermal insulation sheet grades need a bonded facing on both sides - Service conditions — continuous temperature, peak temperature, cycling frequency, and any mechanical load - Standards — the test method the figures must be quoted against, such as ASTM C533 for calcium silicate or EN 14306 for high-temperature boards - Quantity and packing — area or piece count, pallet configuration, and whether export packing is needed - Certification — ISO 9001 quality system, plus any project-specific type testing A rigid thermal panel supplier will ask for the same list plus one more item: whether the board is faced, on which side, and whether the facing has to survive the full service temperature. Two questions separate a serious supplier from a trader: whether they will supply a technical data sheet showing the test method behind each figure, and whether they will hold a production sample for comparison against the delivered lot. Both are cheap to ask and expensive to skip. Our insulation board range runs from rock wool board through calcium silicate insulation board to ceramic fiber board and nano aerogel blanket, all produced under an ISO 9001 quality system. For the refractory-side comparison of the same two leading high-temperature boards, see refractory board selection. Form first, material second, grade third. That order gets a quotation back in days instead of weeks, and it gets a board that fits the position you designed for. FAQ: Q: Is board the same as panel in insulation? A: Not quite, and the difference matters at quotation stage. Board is a rigid, self-supporting flat slab, typically 12–150 mm thick, that is handled as a piece of material. Panel implies a larger format or a composite assembly installed as a system — a rock wool sandwich panel with metal faces, a glass wool duct panel, or a vacuum insulation panel, which is always called a panel because it is a sealed evacuated unit. Some suppliers use the two words interchangeably for the same product; when they do, the fixing detail and format on the data sheet tell you which behaviour to expect. Q: When should insulation tile be used instead of board? A: Only for genuine masonry units. Tile describes small rectangular blocks laid course by course, which in practice means insulating firebrick in the 230 × 114 × 65 mm format, plus refractory tiles for hearths, flues and burner blocks. Calcium silicate, ceramic fiber, rock wool and glass wool are sold as board, and asking a supplier for those materials in tile form simply adds a round of clarification. Ceramic fiber in particular is never called tile in industrial trade usage. Q: What thickness separates sheet from board? A: The practical boundary is behaviour rather than a fixed number. Below about 6 mm, or any product that will not stand on edge, is a sheet — ceramic fiber paper at 1–6 mm is the classic example, used for gaskets and parting layers. Above 12 mm with enough stiffness to be self-supporting is a board. Between 6 and 12 mm the two words overlap and the data sheet governs. The same rule separates sheet from panel on the thin end of the nano-porous products. Q: Which insulation board handles the highest temperature? A: Among the common families, ceramic fiber board — rated by classification temperature at 1260 °C, 1400 °C and 1450 °C — with continuous service below those figures. Above roughly 1400 °C the specification moves to zirconia-bearing grades, polycrystalline mullite board and alumina fiber board, which reach 1600 °C and beyond at a considerably higher cost. Microporous board covers 900–1200 °C where thickness is limited, while calcium silicate tops out around 1000 °C and rock wool around 650 °C. Q: What exactly is a rock wool sandwich panel? A: A factory-bonded assembly with a rock wool core between two metal faces, installed as a building envelope element rather than as insulation that is then clad. It carries its own fire and acoustic performance as a tested system, which is why the specification covers core density, facing gauge, panel length and fixing detail rather than just the insulation thickness. Sandwich panel is the single most common industrial use of the word panel, and it is a distinct product from rock wool board supplied loose. Q: How long does a vacuum insulation panel last? A: A service life of 20–25 years is typically quoted, and it is governed by barrier permeation rather than by the core material: as gas slowly enters through the barrier film, conductivity rises from around 0.004–0.007 W/(m·K) towards that of a conventional board. Mechanical damage ends the life instantly, because a puncture destroys the vacuum. Panels cannot be cut or drilled on site, so any penetration has to be designed in and the panel sized accordingly — which is why VIP suits cold-chain packaging and refrigerated containers far better than maintained plant. Q: What should an enquiry for insulation board always specify? A: Material and grade, density in kg/m³, thickness with tolerance, board size and edge profile, facing, service conditions including continuous and peak temperature plus cycling, the test standard the figures must be quoted against, quantity and packing, and the certification required. Each of those changes the price, and a missing density or test method is the most common reason two quotations cannot be compared. Ask as well whether the supplier will provide a data sheet showing the test method behind each figure and hold a production sample for comparison against the delivered lot. ### Cryogenic Insulation Applications: Cold Storage, Cold Chain and LNG URL: https://www.rosetexwool.net/news/cryogenic-insulation-applications-cold-storage-lng/ 2026-09-13 | Author: Rosetexwool Editorial | Category: industry insight Summary: Cryogenic insulation by scenario: cold storage, cold chain and LNG duty compared, with the materials that carry thermal resistance and the ones that do not. Quick answer: Cryogenic insulation is specified by scenario, not by material data sheet. Three bands cover almost every job: cold storage from about +10 °C down to -45 °C, cold chain transport and packaging between +8 °C and -18 °C, and LNG at -162 °C. In the first two, closed-cell rigid foam carries the thermal resistance and the fibre products are limited to fire breaks, facings and acoustic linings. In LNG, the real thermal resistance comes from expanded perlite, foam glass and closed-cell cryogenic foam, with aerogel blanket taking thin sections, valves and retrofits. The first decision in every band is moisture, not conductivity: ice conducts roughly 2.2 W/(m·K), about eighty times dry air, and once it forms inside the layer the damage is permanent. Most insulation guides rank materials by thermal conductivity and stop there. That approach works for a hot pipe and fails for cryogenic insulation, because the numbers on the data sheet are measured dry. In cold service that ranking is close to useless, because the numbers are quoted dry and at ambient, and the failure mode that actually ends a cryogenic insulation system is water that got in and froze. This guide works through the three application bands, then places each material where it genuinely belongs. What Counts as Cryogenic: Three Temperature Bands "Cryogenic" is used loosely in the trade, so it is worth fixing the bands before anything else. Band | Typical range | Sub-divisions | What drives the design | Cold storage | +10 °C to -45 °C | Chill 0 to 10 °C, cold store -2 to 5 °C, frozen -18 to -25 °C, blast freezing -35 to -45 °C | Humidity load, door openings, floor frost heave | Cold chain | +8 °C to -18 °C; pharma 2 to 8 °C; special -60 °C | Refrigerated vehicles and containers, pharma shippers, dry ice and liquid nitrogen | Weight, puncture resistance, hold time | LNG | -162 °C throughout | Liquefaction, storage tank, carrier, regasification, BOG lines | Vapour drive, thermal cycling, boil-off rate | Cold storage and cold chain are not, strictly speaking, deep cryogenic duty — the physics of moisture still governs them, which is why they belong in the same discussion. LNG is the only band where the temperature itself rules materials out. Why Cryogenic Insulation Fails Differently In a warm building, an insulation layer that gets damp can dry out again. On a cold line or a cold wall, the surface sits permanently below the ambient dew point, so water vapour moves towards the cold face under a partial-pressure difference that never reverses. There is no drying phase. Whatever gets in, stays in — and freezes. Two consequences follow, and both are unforgiving. First, ice is a conductor. At roughly 2.2 W/(m·K) it conducts about eighty times better than still air and more than fifty times better than a dry fibre mat. A layer that is only a few percent ice by volume has already lost a large part of its thermal value, and the loss is not recovered when the plant warms up, because the melt water is still there. Second, water expands about 9 % when it freezes. That expansion prises open joints, splits rigid boards, lifts facing materials off the substrate and opens the very paths that let more vapour in. The failure accelerates. This is why the first question in any cryogenic insulation specification is about water vapour permeance and closed-cell content, not about the ambient conductivity number quoted at the top of a data sheet. Once moisture is under control, conductivity becomes a fair comparison again — and only then. The Vapour Barrier Belongs on the Warm Side The single most common installation error in cold work is putting the vapour retarder on the wrong face. It belongs on the warm, high vapour-pressure side of the insulation — the outside of a cold room wall, the outside of a chilled line. Set it on the cold side and the whole insulation layer sits inside the condensing zone for its entire service life. Design practice in cold storage requires a vapour barrier whenever the temperature difference across the envelope exceeds about 5 °C, which in this duty is always. Every cryogenic insulation system is, in the end, a vapour control system with a thermal layer inside it. In practice that means a continuous membrane, fully sealed laps, foil tape over every board joint, and penetrations foamed rather than stuffed. Cold Storage Facilities: +10 °C to -45 °C The main thermal resistance in a cold store — and the part most people mean when they say cryogenic insulation for a building — is closed-cell organic foam: metal-faced PIR or PUR sandwich panels at roughly 0.020–0.024 W/(m·K) with a closed-cell content above 90 %, or site-applied sprayed foam where a seam-free envelope is wanted. Floors use extruded polystyrene, typically specified at 200 kPa compressive strength or better, combined with a ventilated or heated sub-floor to stop frost heave. Indicative thicknesses: 100–120 mm for a 0 °C chill room, around 150 mm at -18 °C, and 200 mm or more below -35 °C. Where does mineral wool fit? Not as the main thermal layer. Rock wool and glass wool appear in cold storage as the facing of a PIR sandwich panel, as fire breaks dividing a large envelope, as an external fire-rated layer outside the main insulation, and in acoustic linings. The reason is the one given earlier: these are open-cell products, water repellent treatment sheds liquid water but does not stop vapour, and once the fibre is wet its conductivity climbs steeply. Water conducts at about 0.6 W/(m·K), twenty-odd times air. Cold Chain Transport and Packaging Transport bodies are integral-skin rigid foam or composite sandwich panels with sealed door frames — weight and structural integrity matter as much as thermal value. The interesting engineering is in packaging. Cold chain packaging is where cryogenic insulation design gets closest to precision engineering, because weight and hold time are both money. High-value pharmaceutical shippers use a composite: a structural PU shell, VIP vacuum insulation panels embedded in it, and phase-change material packs arranged on all six faces. A well-built shipper holds 2–8 °C for 72 to 120 hours in a 35 °C ambient. VIP cores give conductivity down to 0.002–0.008 W/(m·K), four to eight times the thermal resistance of conventional foam in the same thickness. The trade-offs are real. A VIP cannot be cut on site — it has to be ordered to size and the panel layout designed around it. Puncture destroys it. Vacuum life is commonly five to ten years, and over ten to twenty-five years conductivity drifts towards one and a half to two times its initial value. For a reusable shipper that is a maintenance question, not a deal-breaker; for a buried tank it would be. LNG: The Deep Cryogenic End At -162 °C the material list collapses to what survives thermal cycling, vapour drive and mechanical load at that temperature. This is the band where cryogenic insulation stops being a building services question and becomes a process engineering one. Onshore full-containment tanks. An elastic felt layer — mineral wool or glass wool, around 400 mm — sits directly against the inner tank wall. It is not there for thermal resistance; it absorbs the contraction of the inner tank during cooldown and cushions the pressure of the fill behind it. The annulus is filled with expanded perlite, roughly 800 mm, which is the actual thermal resistance. The tank bottom uses foam glass brick, around 200 mm, chosen because it carries load, resists vapour and survives frost heave. The annular space is kept at a slight positive pressure with dry nitrogen so that any leak path flows outwards. Carriers. Modern membrane containment systems use a thin corrugated metal primary barrier over insulated boxes filled with reinforced closed-cell foam; spherical designs carry multi-layer insulation externally under an aluminium weather cover. Process piping and regasification. Closed-cell cryogenic foam is the standard, installed in two or three staggered layers once total thickness passes about 127 mm. Foam glass is used at pipe supports and anywhere a load has to cross the insulation — the cold bridge positions. Aerogel blanket is specified for valves, complex shapes, congested areas and retrofit work, where its low conductivity allows 50–60 % less thickness than foam or foam glass for the same duty, and where its fire performance helps meet jet-fire protection requirements under NFPA 59A. Design targets are tight: a large full-containment tank is typically specified for a boil-off rate at or below 0.05 % per day. Where Rock Wool and Glass Wool Actually Fit This is the question our customers ask most often, and the honest answer is more useful than a flattering one. Rock wool has a real place in cryogenic insulation, and it is not the place most specifications try to put it. Rock wool with hydrophobic treatment at 99 % or better, installed with a continuous vapour barrier and metal jacketing, performs reliably down to about -50 °C. That covers a large part of cold storage, all pharmaceutical cold rooms, chilled water and most industrial cold ductwork. It is A1 non-combustible, which matters wherever fire separation is part of the specification, it is economical, and it is straightforward to install on site. Our rock wool pipe sections and rock wool board are specified into exactly this band. Below -50 °C the picture changes, and at -162 °C rock wool is not a primary thermal resistance material. The fibre itself is not the limiting factor — mineral wool survives temperatures far below this without embrittling, and it is routinely used in plant that sees cryogenic duty. What changes is the consequence of moisture: at these temperatures any water vapour that reaches the layer turns to ice, and ice conducts roughly fifty times better than the dry fibre it displaces. It still has a role: the elastic felt layer against an LNG inner tank wall described above is a mineral wool or glass wool product, and it is doing mechanical work — compensating contraction and cushioning the perlite — rather than thermal work. Glass wool sits lower again. It can be hydrophobic treated, but it is best kept above about -20 °C, and in cold storage it earns its place through acoustic linings and duct insulation rather than through the envelope. Material | Practical cold limit | Role it actually plays | Hydrophobic rock wool | About -50 °C | Cold rooms, chilled lines, fire breaks, LNG tank elastic felt | Hydrophobic glass wool | About -20 °C | Ducts, acoustic linings, filling | Calcium silicate | About -20 °C | Ambient-to-warm service, not cold work | Ceramic fiber | Not a cold material | High-temperature duty only | Where Aerogel and Nano-Porous Insulation Win Aerogel blanket is the one material in this range that is comfortable across the whole cryogenic span, and it is the reason deep cryogenic insulation can now be built thin enough to fit inside existing plant. At -196 °C its conductivity sits around 0.018–0.022 W/(m·K), roughly a third of what conventional materials manage at the same temperature, so a thin layer does the work of a much thicker one. It is flexible enough to wrap a valve body without a single cut joint, it is hydrophobic, and it is non-combustible. That combination is why aerogel is used where thickness is expensive — offshore modules, congested pipe racks, retrofit inside an existing envelope — rather than across every metre of a long line. Cost per cubic metre runs many times that of foam or mineral wool, and it still needs a vapour barrier system designed around it. Vacuum insulation panels are a different proposition: unbeatable conductivity, zero tolerance for site cutting or puncture, and best suited to controlled packaging applications. For deep cryogenic plant, the vacuum life under vibration and thermal cycling is not yet reliable enough to make VIP a mainstream choice. Materials That Do Not Belong in Cold Service Two products on our own catalogue are asked for in cold specifications and should not be. Saying so plainly costs us an order occasionally and saves a cold room every time, which is a trade worth making. Ceramic fiber is designed for 1,000–1,400 °C service. It has nothing to offer at -162 °C, it becomes brittle at low temperature, and specifying it in cold work is a category error rather than a marginal call. Calcium silicate is a rigid, high-strength, high-temperature product. It absorbs water, it is heavy, and freeze-thaw cycling cracks it. Its practical floor is about -20 °C; below that, rock wool or aerogel is the right answer. Saying this plainly costs us nothing and saves a cold room. Cold Bridges and the Details That Fail Almost every cryogenic insulation failure we get called about is a detail, not a material. The material was chosen correctly, the thickness was calculated correctly, and the system still failed at a joint. Cold bridges form at slab joints, beams and columns, wall penetrations, door frame fixings and metal pipe supports. They show up as surface condensation, then icing, then frost spreading outwards. The fix is systematic: foamed penetrations, foil tape over joints, thermally broken sections, and foam glass or aerogel pads wherever a load crosses the insulation. Thermal cycling is the second offender. Pre-cooling and restart crack rigid foam and foam glass if the joint layout does not allow for movement, and the crack then becomes an internal icing site. In perlite-filled annuli, long-term settlement opens a void at the top of the tank, and tank foundation heating that is undersized lets frost heave lift the base. Insufficient insulation shows up directly as excess boil-off gas, which then overloads the recondenser. Selecting Cryogenic Insulation by Scenario - Fix the temperature band and the duty cycle. Continuous or cycling, and how far. This rules materials in or out before conductivity is considered. - Design the vapour barrier first. Warm side, continuous, sealed, and detailed at every penetration. - Choose the primary thermal resistance. Closed-cell foam for cold storage and cold chain; perlite, foam glass and cryogenic foam for LNG; aerogel where thickness is constrained. - Assign the secondary roles. Fire separation, elastic buffer, load bearing, acoustics. Rock wool earns its place here in almost every band. - Detail the joints, supports and penetrations. This is where the warranty is won or lost. Scenario | Primary thermal resistance | Secondary roles | Do not use | Cold storage | PIR/PUR panels, sprayed foam, XPS floors | Rock wool as facing, fire break, acoustic | Ceramic fiber, calcium silicate | Cold chain | Integral PU; VIP plus PCM for pharma | EPP casing, anti-puncture layers | Open-cell fibre in the cold layer | LNG tank | Expanded perlite, foam glass base | Mineral wool elastic felt as buffer | VIP, ceramic fiber, calcium silicate | LNG piping | Closed-cell cryogenic foam, foam glass at supports | Aerogel for valves, shapes, retrofit | Single-layer thick foam with unstaggered joints | Related Reading - Cryogenic pipe insulation guide — materials, thickness and installation for cold lines - Aerogel versus traditional insulation — where the thickness saving justifies the cost - What temperature can rock wool withstand? — the practical limits of the fibre - Industrial pipe insulation materials compared See our cryogenic and LNG insulation applications guide for cold-storage, LNG, and liquefied-gas cryogenic insulation systems. FAQ: Q: What temperature range counts as cryogenic insulation? A: In practice three bands are grouped together: cold storage from about +10 °C down to -45 °C, cold chain transport and packaging between +8 °C and -18 °C with pharmaceutical work at 2–8 °C, and LNG at -162 °C throughout. Only the last is true deep cryogenic duty, but all three are governed by the same moisture-driven failure mechanism, which is why they are specified the same way. Most materials are comfortable in the upper band and ruled out by the lower one. Q: Can rock wool be used for cryogenic insulation? A: Yes, down to about -50 °C, provided it is a hydrophobic grade — 99 % water repellency or better — and provided it is installed with a continuous vapour barrier and metal jacketing. That covers cold rooms, chilled water lines, pharmaceutical cold stores and most industrial cold ductwork. Below -50 °C it is not a primary thermal resistance material, though it still appears in LNG tank construction as the elastic felt layer against the inner tank wall, where it absorbs contraction rather than carrying thermal duty. Q: Why must the vapour barrier go on the warm side? A: Because vapour moves from high partial pressure to low, which on a cold line means inwards. If the retarder is on the cold face, the entire insulation layer sits inside the condensing zone and never dries. On the warm face it stops vapour before it reaches cold material. Cold storage design codes require a vapour barrier whenever the temperature difference across the envelope exceeds about 5 °C, which in this duty is always the case. Laps must be sealed, joints taped and penetrations foamed, because a barrier with holes is not a barrier. Q: What insulation is used in LNG storage tanks? A: A full-containment tank uses several materials, each doing a different job. Expanded perlite, roughly 800 mm deep, fills the annulus and carries the thermal resistance. An elastic mineral wool or glass wool felt around 400 mm sits against the inner tank wall to absorb contraction and cushion the perlite load. Foam glass brick, about 200 mm, forms the tank base because it carries load, blocks vapour and resists frost heave. The annular space is held at a slight positive pressure with dry nitrogen so any leak path flows outwards rather than inwards. Q: Is aerogel worth the cost for cryogenic duty? A: Where thickness is constrained, yes. Aerogel blanket runs around 0.018–0.022 W/(m·K) at -196 °C, so it can replace 50–60 % of the thickness that closed-cell foam or foam glass would need for the same duty, and it wraps valves and complex shapes without cut joints. That makes it the practical choice for congested pipe racks, offshore modules, retrofit inside an existing envelope and anywhere jet-fire protection is required. On a long, accessible line with space to spare, foam or mineral wool usually wins on economics, and aerogel still needs a vapour barrier designed around it. Q: Can I use ceramic fiber or calcium silicate for cold service? A: No. Ceramic fiber is a 1,000–1,400 °C material with nothing to offer at cold temperatures, and it becomes brittle as it cools. Calcium silicate is rigid and strong but absorbs water and cracks under freeze-thaw cycling, with a practical floor around -20 °C. Specifying either in cold work is a category error rather than a marginal call — use hydrophobic rock wool down to about -50 °C, and aerogel, closed-cell cryogenic foam or foam glass below that. Q: Which cryogenic insulation failures are most common? A: Moisture ingress is first, and it is almost always a detailing failure rather than a material failure — a vapour barrier on the wrong face, an unsealed lap, a penetration that was stuffed instead of foamed. Cold bridges at supports, slab joints and door fixings come second. Third is thermal cycling: pre-cooling and restart crack rigid foam and foam glass when the joint layout does not allow for movement, and the crack then becomes an internal icing site. In perlite systems, long-term settlement opens a void at the top of the annulus, and under-sized foundation heating lets frost heave lift the tank base. ### Glass Wool Board vs Blanket vs Batt: Form Selection Guide (2026) URL: https://www.rosetexwool.net/news/glass-wool-board-vs-blanket-vs-batt/ 2026-09-11 | Author: Rosetexwool Editorial | Category: industry insight Summary: How to choose between glass wool board, glass wool blanket and glass wool batt: density ranges, load and geometry limits, temperature grades and facings. Quick answer: All three forms insulate about the same — thermal conductivity sits in the 0.030–0.044 W/(m·K) band whichever you pick. The difference is mechanical. Choose glass wool board when the surface is flat and the insulation has to take load, foot traffic or wind pressure. Choose glass wool blanket when the surface curves, bends or is covered in elbows, valves and flanges. Choose glass wool batt when the job is filling a cavity or covering a large area quickly, especially where a facing is wanted for vapour control. That is the whole decision in one sentence, and most of the cost overruns in this product family come from getting it wrong. Put another way, the board vs blanket question is never really about thermal performance — it is about whether the insulation has to hold a shape or follow one. A low-density glass wool blanket fitted to a duct with insulation pins will sag and pull off within a season. A rigid glass wool board cut into eight pieces to wrap a valve will leave six gaps that leak heat. This guide sets out where each form comes from, what its numbers actually mean, how to run the selection in five questions, and what to check before you sign off a delivery. Board, Blanket and Batt: Where the Line Sits Between Them The confusion starts with the words. In international trade, glass wool batt and glass wool blanket are often used interchangeably, and suppliers are not always careful about the difference. The distinction that matters is this. A glass wool blanket is a continuous flexible roll, supplied in long lengths, intended to be cut on site and wrapped around something. A glass wool batt is pre-cut to a standard width — typically matching 400 mm, 600 mm or 1,200 mm stud and purlin spacing — and usually arrives with a factory-applied facing of foil, kraft paper or FSK. Blankets wrap; batts fill. That difference in purpose has consequences. Because a glass wool batt is expected to be handled in pre-cut lengths and pushed into a cavity, it is usually specified a little firmer than the softest blanket and it almost always carries a facing. Because a glass wool blanket is expected to conform, it is usually supplied softer and may be unfaced. Glass wool board is the third member of the family and the only one with structural ambition. It is a rigid or semi-rigid slab, cured so that it stands on edge, holds its dimensions and can be fixed with mechanical fasteners. The useful thing to hold on to is that all three are the same material. Same glass, same fiberizing process, same chemistry. What changes is density, binder content and how far the binder is cured. Once you see the forms as three settings on the same machine rather than three different products, the specification gets much easier. What Makes One Form Rigid and Another Soft Three process variables decide whether a given line run makes glass wool board, glass wool blanket or glass wool batt. Density. More fiber per cubic metre means more fiber-to-fiber contact, which means higher compressive and tensile strength. It also means less flexibility and more weight. Industrial glass wool board typically runs 24–100 kg/m³ with 32–64 kg/m³ as the everyday band; glass wool blanket runs 10–32 kg/m³ and is rarely specified below 16 kg/m³; glass wool batt usually sits at 12–32 kg/m³. Binder content and cure. The resin holding the fiber together is what turns a mat into a board. More binder and a hotter, longer cure give a rigid slab. Less binder and a lighter cure leave the product open and springy — which is exactly what a glass wool blanket needs so it can be compressed into a gap and spring back. Fiber orientation. Fibers laid with a bias towards the horizontal plane give better compressive strength through the thickness, which is what a board needs. A more random orientation gives even properties in all directions, which suits a blanket that will be wrapped in any direction. Put together, that gives the rule of thumb: high density plus more binder plus full cure equals strong and stiff; low density plus less binder plus light cure equals soft and conformable. Semi-rigid board in the 32–64 kg/m³ band, and faced products with a reinforced foil or glass cloth laminate, are the two ways the industry splits the difference. Glass Wool Board: The Rigid, Load-Bearing Form Glass wool board is the form to reach for when the insulation has to behave like a building component rather than a wrapping. Typical figures for industrial glass wool board: - Density: 24–100 kg/m³, with 32–64 kg/m³ covering most work and 80–100 kg/m³ used where the surface will be walked on - Thickness: 20–150 mm, commonly in 25 mm steps - Panel size: 600 × 1,200 mm and 1,200 × 1,200 mm are the usual standards - Thermal conductivity: 0.032–0.040 W/(m·K) at around 25 °C mean temperature - Compressive strength: roughly 20 kPa at 24 kg/m³, 40 kPa at 48 kg/m³ and 80 kPa at 96 kg/m³, measured at 10 % deformation - Acoustic absorption: NRC around 0.85–1.00 for a 50 mm board in the 32–48 kg/m³ range The applications follow from those numbers. Rectangular and round HVAC ductwork is the classic case, because boards take insulation pins properly and because duct in a ceiling void gets stepped on. External wall and curtain wall linings use glass wool board at 48 kg/m³ or above because the insulation has to carry its own weight plus wind-induced vibration without settling. Roof decks, equipment shells on boilers and heat exchangers, and acoustic ceilings all reward the same properties. The limits are equally clear. Glass wool board cannot follow a small radius. Anything with a tight curve has to be cut into segments, and every cut is a joint and every joint is a place for heat to leave and moisture to enter. Board is also the most expensive of the three per cubic metre, so using it where a glass wool batt would do is money wasted. Glass Wool Blanket: The Flexible Wrap Glass wool blanket is what you use when geometry defeats a flat panel. Typical figures: - Density: 10–32 kg/m³, with 16 kg/m³ the practical floor most standards set - Thickness: 25–150 mm - Roll size: 600–1,200 mm wide, 3–20 m long - Thermal conductivity: 0.030–0.040 W/(m·K), the same band as glass wool board - Facings: unfaced, foil, glass cloth, reinforced foil, or stitched for extra strength The characteristic applications are all awkward shapes. Pipe elbows, tees, valves and flanges get wrapped in low-density glass wool blanket at 16–32 kg/m³, sealed with foil tape, and finished without a single gap. Vessel shells, turbine casings and reactor heads get cut blanket-work much the way a tailor cuts cloth — multiple overlapping layers held with wire mesh or banding. Curved steel roof decks get 12–24 kg/m³ foil-faced glass wool blanket pressed into the profile of the sheeting. Narrow cavities are simply stuffed and left to spring back. The trade is honest: a glass wool blanket gives you a seamless fit and fast installation, but it carries no load at all. Compress it and it stays compressed. On vertical and overhead surfaces it needs real mechanical support, and over a long service life any blanket that is under-supported will settle. Glass Wool Batt: The Cavity and Large-Area Form Glass wool batt is the production-oriented member of the family: pre-cut, faced, and designed to be installed fast over big areas. Typical figures: - Density: 12–32 kg/m³ for building grades, with bespoke products spanning 10–72 kg/m³ - Thickness: 50–150 mm - Width: cut to match stud or purlin spacing, typically 400 mm, 600 mm or 1,200 mm - Thermal conductivity: 0.030–0.044 W/(m·K) - Facings: foil for vapour control and radiant reflection, kraft or FSK where a dedicated vapour retarder is needed Light steel stud partitions are the reference application: the glass wool batt arrives at the right width, pushes into the cavity, springs open against the studs and delivers thermal and acoustic performance in one pass. Purlin bays, attic floors, suspended ceilings, cold store envelopes and lightweight marine bulkheads all use the same logic. Two cautions. First, if the cavity does not match the pre-cut width, the installer cuts on site and you lose the labour saving that justified choosing glass wool batt in the first place. Second, a torn facing is not a cosmetic problem — it is the vapour barrier gone, and on a cold line that means condensation inside the insulation where you cannot see it. Side-by-Side: The 14-Point Comparison Attribute | Glass wool board | Glass wool blanket | Glass wool batt | Form | Rigid to semi-rigid slab | Flexible continuous roll | Flexible pre-cut roll or strip | Density, kg/m³ | 24–100 (usual 32–64) | 10–32 (usual 16–32) | 12–32 (bespoke 10–72) | Thickness, mm | 20–150 | 25–150 | 50–150 | Thermal conductivity, W/(m·K) | 0.032–0.040 | 0.030–0.040 | 0.030–0.044 | Compressive strength | 20–80 kPa at 10 % | Negligible | Negligible to low | Load or foot traffic | Yes, at high density | No | No | Mechanical fixing | Insulation pins, adhesive | Banding, wire mesh | Battens, framing | Curved surfaces | Poor, large radius only | Excellent | Good at moderate curvature | Dimensional stability | Good, will not settle | Fair | Fair | Acoustic absorption | NRC 0.85–1.00 at 50 mm | Good | Good | Facing options | Foil, glass cloth, metal laminate | Foil, glass cloth, stitched | Foil, kraft, FSK as standard | Install speed, large area | Moderate | Fast | Fastest | Cost per cubic metre | Highest | Lowest | Low to moderate | Typical failure mode | Gaps at cut joints | Settling and sagging | Damaged facing | Read the thermal conductivity row carefully. The differences between the three forms are tiny. Everything that actually distinguishes them — strength, conformability, fixing method, speed — sits in the rows below it. Five Questions That Decide the Form 1. What load does the insulation carry? If the answer includes foot traffic, wind pressure on a façade, or self-weight over a tall elevation, you need glass wool board, and above 64 kg/m³ if people will walk on it. If the answer is nothing, glass wool blanket or glass wool batt will do the job for less money. 2. What is the geometry? Flat and regular suits glass wool board. Small radius and awkward shapes — elbows, valves, heads — suit glass wool blanket. Large flat cavities with regular framing suit glass wool batt. Medium curvature is the genuinely undecided case: a semi-rigid glass wool board at 32–64 kg/m³ or a faced glass wool blanket both work, and the choice is usually made on labour cost. 3. What temperature? Standard glass wool runs to about 250 °C continuous, and grades with a different binder chemistry are rated up to roughly 350 °C — the spread is real, so the figure on the data sheet is the one to specify rather than a number remembered from a previous project. High-temperature grades reach roughly 538 °C continuous with peaks 100–200 °C above that. Above the standard band, the form matters less than the grade: a glass wool blanket and a glass wool board of the same grade have the same limit, and picking the wrong grade is the mistake that destroys linings. Glass wool does not reach the temperatures mineral wool handles, so for duties near or above 600 °C the conversation changes material. 4. Is moisture or condensation in play? Cold lines, chilled water and humid environments need a facing plus hydrophobic treatment with water repellency of 98 % or better. Facing orientation is not optional: foil goes to the warm side and every joint is taped. And where fire performance is specified, remember that the glass wool itself is Euroclass A1 while the facing has its own rating that has to be checked separately. 5. What else does the insulation have to do? For acoustics, density and thickness beat form: a 48 kg/m³ glass wool board at 50 mm reaches NRC values around 0.90–1.00. For cost, compare per unit of thermal resistance installed, not per cubic metre — the cheapest glass wool batt is only cheapest if the cavity fits and the crew is not cutting every piece. Application Quick-Reference Table Application | Form to specify | Density, kg/m³ | What to insist on | Rectangular or round ductwork | Glass wool board | 32–48, minimum 32 | Pin fixing, foil facing | Elbows, valves, flanges | Glass wool blanket | 16–32 | Foil tape on every joint | Long straight pipe runs | Glass wool board or preformed section | 32–64 | Bore matched to pipe, multi-layer if thick | External wall and curtain wall lining | Glass wool board | 48 or above | Dimensional stability, no settling | Steel frame roof deck | Glass wool batt, foil faced | 12–24 | Facing to the warm side | Stud partition and wall cavity | Glass wool batt or semi-rigid board | 24–32 | Pre-cut width matched to studs | Walkable roof or floor | Glass wool board, high density | 64 and above, with a protective facing | Compressive strength at 10 % deformation | Vessel heads and casings | Glass wool blanket, multi-layer | 16–32 | Wire mesh or banding | Ceilings and acoustic treatment | Glass wool board | 24–48 | Absorption coefficient, visible facing | Cold store and chilled water lines | Glass wool blanket or batt with foil | 24–48 | Water repellency 98 % or better, sealed vapour layer | Hot lines above 250 °C | High-temperature grade, board or blanket | Per data sheet | Maximum service temperature and shrinkage temperature | Six Specification Mistakes That Cost the Most Specifying the highest density you can afford. Thermal conductivity falls as density rises, then rises again. Past roughly 64 kg/m³ you are buying weight and money, not performance. The efficient band for building work sits closer to 24–48 kg/m³. Using glass wool blanket on ductwork. Low-density glass wool blanket cannot hold an insulation pin and cannot take being walked on. It sags, pulls off the pins and the duct is bare within a year. Treating the facing as decoration. Foil orientation, joint taping and vapour retarder continuity are the whole point of a facing on glass wool batt. Get the orientation wrong or leave the joints open and condensation forms inside the insulation. Checking thermal conductivity and ignoring density tolerance. Standard product specifications limit the deviation between nominal and measured density, commonly to around ±10 %. A glass wool batt sold as 24 kg/m³ and delivered at 20 kg/m³ can still show a compliant conductivity figure while delivering less insulation than the thickness suggests. Assuming glass wool tolerates any temperature. Standard grades are limited to about 250 °C continuous. Above that, fibers sinter, the mat shrinks and the insulation collapses. Where the duty is genuinely hot, move to a high-temperature grade or to mineral wool. Comparing unit prices instead of installed cost. A glass wool batt is cheaper per cubic metre than glass wool board, but if the cavity needs cutting and the board does not, the labour difference can exceed the material saving. Price the assembly: material, fixing, hours and the cost of a callback. What to Check Before Signing Off the Delivery Seven items, and none of them take long: - Thermal conductivity measured against the value quoted in the enquiry, at the stated mean temperature - Density weighed on delivered material, within the agreed tolerance of nominal - Thickness and dimensions, including squareness of glass wool board and width of glass wool batt against the framing it has to fit - Water repellency where moisture is in play, at 98 % or better - Fire classification for the insulation itself — Euroclass A1 for glass wool — and a separate rating for the facing - Maximum service temperature and shrinkage temperature for any duty above the standard 250 °C band - Facing condition on glass wool batt and faced glass wool blanket: no tears, no delamination, no lifted edges Ask for the declared standard and the test report in the enquiry itself, so the delivery can be assessed against something rather than an opinion. Related Reading - Glass wool insulation: buyer's guide — grades, temperature limits and how to read a data sheet - Glass wool blanket: specifications and buying guide — density, thickness and compression packaging in detail - Glass wool board applications — where rigid board earns its cost - Is glass wool blanket waterproof? — water repellency, facings and vapour control - Glass wool vs rock wool: seven differences — when to change material rather than form - Glass wool for acoustic insulation — density, thickness and absorption Ready to compare forms against your own duty? Send the surface geometry, the temperature and the fixing method and we will quote glass wool board and glass wool blanket side by side. FAQ: Q: Is a glass wool batt the same thing as a glass wool blanket? A: Not quite, and the difference matters when you order. A glass wool blanket is a continuous flexible roll meant to be cut and wrapped around something; a glass wool batt is pre-cut to a standard width matching stud or purlin spacing and usually arrives with a factory-applied facing of foil, kraft paper or FSK. Blankets wrap pipes and vessels; batts fill cavities and cover large framed areas. Suppliers sometimes use the two words loosely, so specify the width and the facing rather than relying on the name. Q: Can glass wool blanket be used instead of glass wool board on ductwork? A: It should not be. Low-density glass wool blanket, typically 10–32 kg/m³, cannot hold an insulation pin under load and cannot survive foot traffic in a ceiling void. It sags away from the duct, pulls off the pins and leaves the surface bare. Ductwork wants glass wool board at 32 kg/m³ minimum with a foil facing, rising to 48 kg/m³ or more where the duct is large or the insulation will be walked on. Q: What density should I specify for glass wool board? A: It depends on load, not on thermal performance. General duct and equipment work sits at 32–48 kg/m³. External wall and curtain wall linings, where the insulation carries its own weight plus wind vibration, want 48 kg/m³ or above. Walkable roofs and floors need 64 kg/m³ and above with a protective facing. Acoustic ceilings work well at 24–48 kg/m³. Going above about 64 kg/m³ buys strength rather than insulation, because thermal conductivity stops improving and begins to rise again. Q: How hot can glass wool board and glass wool blanket go? A: The form makes almost no difference; the grade does. Standard glass wool board and standard glass wool blanket both run to about 250 °C continuous service, though grades with a different binder chemistry are rated up to roughly 350 °C — which is why the data sheet, not the product name, should set the limit. High-temperature grades reach roughly 538 °C continuous, with short-term peaks 100–200 °C higher. Above the standard band you must ask for the maximum service temperature and the shrinkage temperature separately, because a lining taken past its limit will sinter and collapse. Where the duty approaches 600 °C, mineral wool is the safer material choice. Q: Does glass wool board need a facing? A: Only where moisture, vapour or appearance is part of the requirement. Bare glass wool board is fine on dry, hot, indoor equipment. Add foil where the surface is cold or the air is humid, where a vapour retarder is required, or where radiant heat is a factor. Note that the glass wool itself is Euroclass A1 non-combustible while the facing carries its own fire rating, so in fire-critical applications — smoke extract ductwork, for example — the facing has to be specified and certified alongside the board. Q: Which form is best for acoustic performance? A: Glass wool board, because absorption responds to density and thickness and board is the form that reaches the useful densities without being compressed. A 50 mm board at 32–48 kg/m³ typically reaches NRC values of 0.85–1.00. Glass wool blanket and glass wool batt absorb well too, but if they are squashed into a cavity their thickness — and therefore their low-frequency performance — drops. Where acoustics are the primary goal, specify the density and the installed thickness, not just the form. Q: Can glass wool batt be used outdoors? A: Not exposed. Glass wool batt is designed for enclosed cavities and protected areas, and neither it nor glass wool blanket is a weathering layer. Outdoors, the insulation needs a cladding or a metal jacket over it, with a facing chosen for vapour control and all joints sealed. In genuinely wet or buried conditions, a closed-cell material is usually the better answer, because glass wool loses most of its insulating value once it is soaked. ### Refractory Board Selection: Calcium Silicate vs Ceramic Fiber Board for Furnace Linings URL: https://www.rosetexwool.net/news/refractory-board-selection-calsil-ceramic-fiber/ 2026-09-11 | Author: Rosetexwool Editorial | Category: industry insight Summary: How to choose refractory board for a furnace lining: hot face or back-up duty, batch or continuous cycling, gas velocity, slag and alkali exposure. Quick answer: For refractory duty, pick the board by position in the lining first, then by cycling, then by chemistry — not by thermal conductivity. A refractory board in the back-up position behind brick or castable, running continuously below about 1,000 °C, is best served by calcium silicate board: it carries load, spans supports and costs less per cubic metre. A board on the hot face of a batch furnace — door, roof, ladle cover, kiln car, burner block — should be ceramic fiber board, because low heat storage and thermal shock resistance matter more there than compressive strength. Above roughly 1,050 °C, ceramic fiber board is the only option of the two. Almost every industrial furnace ends up using both refractory board types, in a composite furnace lining. The same hot-face versus back-up logic is now being applied outside the furnace, where thermal energy storage vessels and battery enclosures put these material families into new duty cycles — see our LDES 2026 report on insulation for long-duration energy storage. The boards are not competing for the same job; they are doing different jobs in the same wall. Most selection guides stop at two numbers: maximum temperature and thermal conductivity. Both of those matter, and neither decides a refractory lining. What decides it is where the board sits in the furnace lining, how often the temperature swings, and what the gas and melt are doing to the surface. This guide works through all three, then turns them into a five-step procedure that ends with a refractory lining specification you can hand to a supplier. Why a General Material Comparison Is Not Enough A side-by-side comparison of calcium silicate board and ceramic fiber board is a useful starting point, and we have published one. It is also, on its own, not enough to specify refractory board. The reason is that a furnace lining is a system, and each position in that system imposes a different set of demands. The board behind the working lining is asked to insulate, carry load and stay put for a campaign. The board facing the flame is asked to survive thermal shock, resist gas velocity and not store so much heat that every cycle wastes fuel. Different jobs, different failure modes, and often different materials in the same wall. Three axes decide it: - Duty position — hot face or back-up. - Operating cycle — continuous and steady, or batch and cycling. - Environment — gas velocity, dust, slag, molten metal, alkali and acid. Get these three wrong and no data-sheet value will save the refractory lining. Get them right and the material choice usually becomes obvious. It is also worth saying what is not on the list: thermal conductivity. It appears later in this guide because it matters, but it belongs at the end of the reasoning rather than the start. Calcium Silicate and Ceramic Fiber Board: The Material Baseline Before the duty assessment, it helps to know what the two boards are. One clarification matters up front: the refractory board discussed here is the lightweight insulation grade of calcium silicate board, around 170–270 kg/m³. That is not the same product as the dense building board used for fire-rated partitions, which runs several times heavier. Data for the building board cannot be used for refractory lining design. Property | Calcium silicate board (insulation grade) | Ceramic fiber board (vacuum formed) | Temperature class | Tobermorite-based ≈650 °C; xonotlite-based 1,000–1,050 °C; ASTM C533 Type II continuous ≈927 °C | Classification 1,260 / 1,360 / 1,430 °C (zirconia); continuous use = classification minus roughly 100–150 °C; polycrystalline alumina fibre to 1,600 °C | Density | 170–270 kg/m³ (light 170–200, standard 200–240, high density 240–270) | 250–350 kg/m³, special orders to about 400 kg/m³ | Thermal conductivity | 0.05–0.06 W/(m·K) at 70 °C; 0.08 at 200 °C; 0.10 at 400 °C; 0.10–0.12 at 600 °C; 0.13–0.15 at 1,000 °C | 0.06 W/(m·K) at 200 °C; 0.085 at 400 °C; 0.11–0.16 at 600 °C; 0.132 at 800 °C; 0.18–0.19 at 1,000 °C | Mechanical strength | Flexural 0.3–0.55 MPa, high density grades above 1.0 MPa; compressive 0.35–2.0 MPa | Compressive 0.2–0.8 MPa; edges are brittle and the board must be anchored and supported | Permanent linear change | ≤2 % after 3 h at rated temperature; 1.3–1.8 % on high-purity grades | ≤3.0 % after 24 h at 1,000 °C; ≤3.5 % after 24 h at 1,350 °C | Thermal shock | Moderate to poor; rapid heating and cooling cracks it, and site breakage rates are high | Excellent; the first choice for batch plant, furnace doors and covers | Gas velocity and abrasion | Hard and dense, tolerates light abrasion better | Stiffer than blanket, but hot faces above about 5 m/s need surface hardening | Chemical resistance | Silicate based; not resistant to HF or strong alkali; must not contact molten steel or slag | Resists weak acid and weak alkali; not wetted by molten aluminium; not for direct contact with molten steel or aggressive slag | Water and fabrication | High water absorption, becomes fragile when wet, higher cutting loss | Can be made water repellent, absorbs almost nothing, suited to precision machining of shaped parts | Heat storage | High heat capacity | Low heat capacity; fast heat-up and real fuel savings on batch plant | Cost position | Mid to low price; high value as a back-up layer | Higher cost per cubic metre; justified at high temperature or where shapes must be machined | Typical standards | ASTM C533; EN 14306 | ASTM C892; EN 1094-1 | Two entries in that table deserve emphasis, because they cause the most argument on site. The density figures put calcium silicate board and ceramic fiber board in the same broad band, so weight is rarely the deciding factor. And the conductivity figures overlap across most of the working range, which we return to below. Axis 1 — Duty Position: Hot Face or Back-Up The first question is simply where in the refractory lining the board goes. Back-up and outer layers — behind refractory brick or castable, in flues, in vessel insulation layers, and as external fire barriers on furnace shells. Here calcium silicate board is usually the right refractory board. It is rigid, it carries load, it can span between supports without sagging, it tolerates light abrasion, and it is the more economical back-up insulation. High density grades are specified where the back-up layer has to carry mechanical load, and the difference in load-bearing capacity between a 240 kg/m³ board and a 170 kg/m³ board is large enough to matter in the design. A high density calcium silicate board will also take the incidental knocks of plant life — a ladder against the shell, a foot on a ledge, the vibration of a fan downstream — that would break the edge of a light board in the same position. Hot face — in direct contact with flame or hot combustion gas. Ceramic fiber board can serve as a hot face within its classification temperature. Calcium silicate board above about 600 °C is generally a back-up material rather than a hot-face one, and is not recommended where it would face high-velocity hot gas directly. The 600 °C figure is not a hard limit on the material; it is where the risk profile changes. Below it, calcium silicate board behaves predictably on a hot face. Above it, the combination of shrinkage, thermal shock and gas erosion shortens service life sharply. Axis 2 — Operating Cycle: Continuous or Batch The second question is how the temperature behaves over time, and it is the one most often skipped. Batch and intermittent plant — furnace doors, furnace roofs, ladle covers, kiln cars, batch heat-treatment furnaces. Thermal shock and heat storage are the dominant problems. Ceramic fiber board has low heat capacity and excellent thermal shock resistance, so it heats and cools with the cycle instead of fighting it, and the fuel saved over a campaign of short cycles is substantial. Calcium silicate board under repeated heating and cooling carries a high cracking risk, and there are many documented field failures to that effect. Continuous, steady-state plant — long campaigns with stable temperature and no violent swings. Where the temperature sits below about 1,000 °C and the gas is slow and lightly loaded, a calcium silicate board back-up is the value choice. Thermal shock is not the governing failure mode, so the board's weakness in that respect costs nothing. This is usually the moment when the specification becomes clear. A ladle cover that cycles twice a shift is a ceramic fiber board application whatever the conductivity table says. A continuous annealing furnace backing wall at 800 °C is a calcium silicate board application whatever the shock resistance table says. Where a furnace lining sees both — a continuous campaign punctuated by weekend shutdowns, for instance — treat it as cycling plant. Weekend cooling is enough to initiate the cracking that eventually ends the campaign, and the material that survives it is the one specified for cycling duty. Axis 3 — Environment: Gas Velocity, Slag, Molten Metal and Alkali The third axis is a set of vetoes. These override everything else, because none of them can be engineered around by choosing a different thickness. - High-velocity dust-laden gas above about 5 m/s. A ceramic fiber board hot face needs surface hardening — a silica-sol or similar treatment — or the hot-face material should change to castable or brick. Calcium silicate board belongs on the low-velocity side. - Direct contact with molten steel or aggressive slag. Neither board is acceptable. The working lining has to be refractory brick or castable. This is not a preference; both boards will fail. - Aluminium and non-ferrous melting. Ceramic fiber board is not wetted by molten aluminium and is suitable. Neither board is suitable in strong alkali or HF environments. Note that these are genuine vetoes, not gradations, and no refractory board in either family is exempt from them. Once one applies, the fibre-versus-silicate question is already settled, and the remaining decision is about the working face of the furnace lining rather than the insulation layer. Thermal Conductivity Is Not the Tie-Breaker There is a persistent belief that ceramic fiber board always insulates better than calcium silicate board. Across the range where both are viable, that is not borne out by the data, and specifying on it will sometimes lead you to the wrong board. Between roughly 400 °C and 800 °C the two conductivity curves run close together — 0.10 W/(m·K) against 0.085 W/(m·K) at 400 °C, and comparable values through to 800 °C. The gap is small enough that it is not, on its own, a reason to choose one board over the other. Above about 800 °C the curves separate, with calcium silicate board reaching 0.13–0.15 W/(m·K) at 1,000 °C and ceramic fiber board 0.18–0.19 W/(m·K) at the same temperature — and that reversal surprises a lot of people who assumed fibre always wins. Two further points follow from the numbers rather than from marketing. First, 1,000 °C is the practical ceiling of calcium silicate board, so at that temperature the safety margin is minimal and the risk of shrinkage cracking is rising. A 1,260 °C class ceramic fiber board at a 1,000 °C duty still has generous reserve. That reserve, not the conductivity, is the reason to move to fibre at the top of the range. The practical rule: choose on temperature margin plus duty, and treat conductivity as a tie-breaker only when both boards are otherwise equally suitable. There is a second reason conductivity is a poor primary filter: it is quoted at a mean temperature, and the mean temperature in a furnace lining is not the flame temperature. A back-up board sitting behind 200 mm of brick may run at 400 °C while the hot face runs at 1,200 °C. Specifying on the hot-face figure will systematically overestimate the heat flow through the back-up layer and push the design towards thickness it does not need. A Five-Step Selection Procedure Running the three axes in order gives a procedure that works for most furnace lining work, and it can be walked through in a specification meeting without a single calculation. - Fix the position. Hot face, or back-up and outer layer. - If back-up, specify xonotlite-based calcium silicate board at 1,000 °C class — or the tobermorite-based ≈650 °C grade where the temperature allows it. Constraints: continuous temperature within the grade limit, no rapid quenching, and a dry environment. - If hot face, go to the temperature and cycling test. Batch or rapid-cycling duty — furnace doors, ladle covers, kiln cars — calls for 1,260 °C class ceramic fiber board, using its thermal shock resistance and low heat storage. Continuous duty above 1,000 °C — burner zones, cracking furnaces, high-temperature heat treatment — calls for high-alumina or zirconia fibre board at 1,360–1,430 °C. Continuous duty at or below 1,000 °C with slow gas and light abrasion can stay with calcium silicate board. - Run the environment vetoes. Gas velocity above about 5 m/s means hardening the fibre hot face or changing the hot-face material. Molten steel or aggressive slag rules out both boards. Aluminium and non-ferrous duty favours ceramic fiber board. Strong alkali or HF rules out both. - Confirm thickness and density together. Thickness sets the heat flow; density sets whether the board survives handling, fixing and load. Specifying one without the other is the most common way to get a lining that performs well in the calculation and poorly on site. Composite Linings: How the Two Boards Get Used Together The industry convention, and the arrangement most furnace designers arrive at, is a composite furnace lining. The boards are complementary rather than alternatives: Refractory brick or castable (hot-face working lining) + calcium silicate board (back-up load-bearing insulation) + ceramic fiber board (roof, door, burner blocks and machined shapes). This structure uses each material where its properties pay: the working lining takes the flame and the slag, calcium silicate board carries load and insulates cheaply behind it, and ceramic fiber board handles the positions that cycle, and the shapes that have to be cut or machined. The same division of labour applies inside the ceramic fiber part of the build-up — a rigid hot face, a compliant back-up and loose fibre at the penetrations — as set out in ceramic fiber bulk, blanket and board in one lining. Specifying a single board for an entire refractory lining is usually a false economy. The places where one board is wrong cost more in early failure than the mixing ever costs in procurement complexity. Thickness, Density and Fixing Details Three practical details decide whether the selected refractory board performs as calculated once it is on the wall rather than on a data sheet. Density with a tolerance. Calcium silicate board is offered in light, standard and high density grades across 170–270 kg/m³, and the grade has to be named on the drawing. High density calcium silicate board is the one to specify where the back-up layer carries load or where the surface takes mechanical contact, and it is also the grade to ask for when the board will be cut into narrow strips, because a light board cut to a 100 mm width tends to break before it is fixed. Where the duty is simply to fill a cavity behind a working lining at low temperature, a light grade does the same job for less money. Fixing and anchoring. Ceramic fiber board edges are brittle and the board has little flexural strength compared with its compressive figure, so anchoring and support are design items, not site improvisation. Calcium silicate board is more forgiving in handling but has high water absorption, and a board that has been stored wet and then dried will often crack before it ever sees service. Water management. Because calcium silicate board absorbs water readily and becomes fragile when saturated, dry storage matters more with this material than with any other board in the family. Ceramic fiber board can be supplied water repellent, which also makes it the better choice where condensation during heat-up is expected. None of these three details is difficult, and all of them are cheaper to settle on the drawing than on the scaffold. A refractory board that is right on paper and installed into a wet, unsupported, under-specified position will still fail early — and the failure will be blamed on the material. What This Data Does Not Tell You Honesty about the limits of the numbers is part of specifying them: - Cost conclusions vary and can reverse. Different suppliers reach opposite conclusions on the installed cost of the two boards, depending on density, grade and cutting waste. No market survey sits behind the cost positions stated here. - High-temperature conductivity figures come from technical literature, not from independent measurement of production samples, and they are typical values rather than guaranteed ones. - Shrinkage and thermal shock behaviour are standard test results, which is to say laboratory conditions. A laboratory thermal shock test is not a furnace door cycling twice a shift. The practical consequence is simple for anyone specifying a furnace lining: treat the table as a way to shortlist, and the duty assessment as the way to choose. Where the stakes justify it, ask the supplier for test certificates against the specific order rather than a generic data sheet. Related Reading - Calcium silicate vs ceramic fiber board: the general material comparison - Refractory insulation materials: types, temperature ratings and applications - High-density calcium silicate board: properties and uses - Calcium silicate board density, thickness and thermal conductivity: spec guide - Ceramic fiber blanket, board, paper and cloth compared - High-temperature insulation wool: temperature ratings explained FAQ: Q: Can calcium silicate board be used as a hot-face lining? A: Below about 600 °C, yes, calcium silicate board can serve on the hot face. Above that temperature it is normally a back-up material rather than a hot-face one, and it is not recommended where it would face high-velocity hot gas directly. The combination of shrinkage, thermal shock susceptibility and gas erosion shortens service life sharply once the temperature climbs. For hot-face duty in the 1,000–1,400 °C range, ceramic fiber board is the material to specify. Q: At what temperature do I have to switch to ceramic fiber board? A: Above roughly 1,050 °C, ceramic fiber board is the only option of the two. Calcium silicate board reaches the top of its range around 1,000–1,050 °C for xonotlite-based grades, and tobermorite-based board is limited to about 650 °C. Even where calcium silicate board is technically within its limit, running at the ceiling leaves almost no safety margin and raises the risk of shrinkage cracking, so many designers move to ceramic fiber board earlier than the limit strictly requires. Q: Which refractory board suits a batch furnace door or kiln car? A: Ceramic fiber board, almost without exception. Batch plant — furnace doors, roofs, ladle covers, kiln cars — cycles repeatedly, so thermal shock and heat storage are the governing problems. Ceramic fiber board has low heat capacity and excellent thermal shock resistance, which means it heats and cools with the cycle and saves fuel on every run. Calcium silicate board under repeated heating and cooling has a high cracking risk, and there are many recorded field failures from exactly that application. Q: Can either board be used in contact with molten steel or slag? A: No. Neither calcium silicate board nor ceramic fiber board may be used in direct contact with molten steel or aggressive slag. The working lining in those positions has to be refractory brick or castable. This is a veto rather than a preference — both insulation boards will fail. Ceramic fiber board is suitable around aluminium and other non-ferrous melts because it is not wetted by molten aluminium, but strong alkali and HF environments rule out both materials. Q: Is ceramic fiber board always lower in thermal conductivity? A: No, and this is one of the most persistent misconceptions in refractory board selection. Between roughly 400 °C and 800 °C the two conductivity curves run close together — around 0.085–0.10 W/(m·K) at 400 °C — so the difference is too small to justify a choice on its own. Above about 800 °C the order actually reverses, with calcium silicate board around 0.13–0.15 W/(m·K) at 1,000 °C against 0.18–0.19 W/(m·K) for ceramic fiber board. Select on temperature margin and duty first, and use conductivity only as a tie-breaker. Q: What gas velocity requires a hardened ceramic fiber board hot face? A: Once hot-face gas velocity exceeds about 5 m/s, particularly when the gas carries dust, a ceramic fiber board hot face needs surface hardening — a silica-sol treatment or equivalent — or the hot-face material should change to castable or brick. Below that threshold an untreated board is normally acceptable. Calcium silicate board, being hard and dense, tolerates light abrasion better and is the usual choice on the low-velocity side of a lining. Q: Why do most furnaces use both boards rather than one? A: Because the boards do different jobs in different positions. The conventional composite lining is refractory brick or castable as the hot-face working lining, calcium silicate board as the load-bearing back-up insulation, and ceramic fiber board at the roof, doors, burner blocks and machined shapes. Calcium silicate board is cheaper per cubic metre and carries load; ceramic fiber board handles cycling and complex shapes. Specifying one board for an entire furnace tends to cost more in early failures than mixing ever costs in procurement. ### Ceramic Fiber Rope, Tape, Cloth & Paper: Buying Guide (2026) URL: https://www.rosetexwool.net/news/ceramic-fiber-rope-tape-cloth-paper-buying-guide/ 2026-09-11 | Author: Rosetexwool Editorial | Category: industry insight Summary: Compare ceramic fiber rope, tape, cloth and paper — temperature limits, constructions, reinforcement options, sizing rules and what to put in an enquiry. Quick answer: Ceramic fiber rope, tape, cloth and paper are made from the same aluminosilicate fiber but are built differently, and that difference decides where each one works. Choose ceramic fiber rope for seals around furnace doors, manways and flanges; ceramic fiber tape for wrapping pipe, valves and irregular runs; ceramic fiber cloth for large or awkward surfaces that need cutting and sewing; and ceramic fiber paper for thin gaskets, parting layers and electrical isolation. Pick the fiber grade by continuous service temperature first, then check the reinforcement — the wire, not the fiber, usually sets the real ceiling. Nearly every failed order in this product family comes down to two errors. The first is buying to classification temperature instead of continuous use temperature, which can be 100–150 °C lower. The second is buying a ceramic fiber rope or tape whose reinforcement wire has a lower temperature limit than the duty requires. Get those two right and most of the remaining specification is straightforward. This guide covers all four forms, how they are constructed, where each one belongs, how to size them, and exactly what to put in your enquiry so the material that arrives matches the material you specified. The Four Forms at a Glance Ceramic fiber rope, ceramic fiber tape, ceramic fiber cloth and ceramic fiber paper start from the same raw fiber. What changes is what happens next: braiding and twisting gives ceramic fiber rope, weaving a narrow strip gives ceramic fiber tape, weaving a full-width fabric gives ceramic fiber cloth, and wet-laying a slurry gives ceramic fiber paper. Each route trades strength for conformability, and that trade is what a buyer is really choosing between. Form | Typical continuous range | Core strength | Main limitation | Typical application | Ceramic fiber rope | 650–1,350 °C | Seals irregular gaps and compresses to fill | Consumes a lot of material on wide gaps | Furnace doors, manways, flange and expansion joints | Ceramic fiber tape | 650–1,100 °C | Fast wrapping of pipe and cylindrical runs | Weak crosswise; not for repeated flexing | Pipe, valve and exhaust wrapping | Ceramic fiber cloth | 650–1,260 °C | Cut and sewn to shape for large surfaces | Poor abrasion resistance, sheds fiber when rubbed | Removable covers, fire curtains, expansion joint liners | Ceramic fiber paper | 1,000–1,350 °C | Very thin, flat, easily die-cut | Almost no tensile strength; softens when wet | Thin gaskets, parting layers, element isolation | The ranges overlap because the fiber grade inside the product can be changed, and because the reinforcement — where there is one — pulls the ceiling down. Read the two rows together: the fiber sets the upper bound and the reinforcement sets the real one. Step One: The Fiber Grade Sets the Temperature Ceiling Before comparing forms, fix the fiber grade. All four forms can be made in any of the standard grades below, and specifying ceramic fiber rope or ceramic fiber tape without naming the grade is like ordering steel by shape. Grade | Classification temp | Continuous use temp | Where it is used | Common | 1,050 °C | ≤ 1,000 °C | Flues, ducts, low-temperature plant | Standard | 1,260 °C | ≤ 1,100 °C | General furnace seals, boiler penetrations, most pipe wrapping | High-purity | 1,260 °C | ≤ 1,100 °C | Processes sensitive to iron contamination | High-alumina | 1,350–1,400 °C | ≤ 1,200 °C | Heat-treatment furnaces, ceramic kilns, hotter hot faces | Zirconia | 1,430 °C | ≤ 1,350 °C | Glass contact, severe cycling, peak excursions | Take the temperature at the seal or wrap line, not the furnace interior. A door seal sits between the hot face and the external steelwork and normally runs far cooler than the chamber it closes. Add a safety margin of at least 100 °C to the measured figure, then read the continuous use column. For a fuller explanation of how the two temperature numbers differ across insulation wool families, see our high-temperature insulation wool temperature ratings guide. Ceramic Fiber Rope: Constructions, Reinforcement and Sizing Ceramic fiber rope is the most specified of the four, and the one most often wrongly specified, because "rope" covers three quite different constructions. Twisted ceramic fiber rope is the cheapest and loosest. The yarn is simply twisted together, which means it frays badly when cut and has poor resilience under repeated compression. It suits static, low-pressure gaps that are filled once and left alone. Square braided ceramic fiber rope is dense, holds its shape, and recovers well after compression. It is the default for furnace doors, manway covers and any seal that has to be opened and closed repeatedly, because it resists being squeezed out of the joint. Round braided ceramic fiber rope has a smooth, even surface and is used where the rope sits in a machined groove or around a circular flange, particularly where appearance and consistent contact matter. Sizing is where most field problems start. Two rules cover nearly every case: - In a machined groove: free rope diameter = groove width × 1.1–1.2. A little oversizing gives full contact without forcing the joint apart. - In an unconfined gap: rope diameter = gap × 1.3. The extra diameter is deliberate pre-compression, since a rope that merely touches both faces will leak as soon as the joint moves. Above roughly 25 mm diameter, specify metallic reinforcement. An unreinforced rope that thick tends to slump under its own weight once hot, and the loss of resilience is permanent. Two impregnations are worth knowing. Graphite impregnation improves gas tightness and reduces friction where a seal is compressed against a moving face. Vermiculite impregnation improves resistance to radiant heat and reduces surface erosion. Neither raises the temperature ceiling, and neither should be treated as a substitute for choosing the right grade. We cover the seal-side detail — joint design, compression and gasketing practice — in ceramic fiber rope sealing and gasketing applications. Our ceramic fiber rope range covers the standard braided constructions. Ceramic Fiber Tape: Wrapping Pipe, Valves and Irregular Runs Ceramic fiber tape is a narrow woven strip, typically 20–150 mm wide and 1.5–6 mm thick. It exists because wrapping is often faster than fitting a preformed section: a valve body, a short spool, a flanged joint or an exhaust run can all be insulated by spiral-wrapping tape in a fraction of the time a shaped cover takes to fit. Reinforcement runs lengthwise, which is why tape is strong along its length and weak across it. That directional strength is intentional — it is what stops the tape stretching as it is pulled tight around a pipe — but it means ceramic fiber tape is the wrong choice wherever the joint flexes repeatedly or vibrates hard. A tape wrap on a vibrating line will crack across the weave. Where radiant heat is significant, tape can be supplied with an aluminium foil facing on one side to reflect radiation back toward the pipe. The foil does not change the insulation value of the fiber; it reduces the heat arriving at the fiber in the first place, which keeps the wrap thinner than it would otherwise need to be. Typical duties include steam and hot-air lines, temporary or permanent insulation of exhaust runs, covering valve bodies and flanges, and as a base layer beneath a removable cover. See ceramic fiber tape for the standard widths and reinforcement options. Ceramic Fiber Cloth: Sewable Insulation for Large and Awkward Surfaces Ceramic fiber cloth is woven at full width and behaves like a fabric: it can be cut, sewn, pleated and layered. That makes it the only one of the four that adapts to a genuinely complex shape without being custom manufactured. Weave density drives everything. A denser weave gives higher tensile strength and better abrasion resistance, but marginally higher thermal conductivity, because there is more fiber per unit volume conducting heat. A looser weave insulates slightly better but sheds more. Where the cloth will be sewn into a removable insulation cover, strength usually wins and a denser weave is specified; where it will be laid as a static curtain or liner, the looser weave is acceptable. Reinforcement is available in both warp and weft directions, and cloth can also be laminated with aluminium foil on one or both faces for radiant duty. The honest limitations deserve stating plainly. Ceramic fiber cloth powders at the surface under repeated friction, so it is not a wearing surface. It should not be used where it will sit permanently soaked in strong acid or alkali, because the fiber is attacked and the fabric loses integrity. And it is heavier per square metre than blanket, so for a simple flat panel it is rarely the economical choice — ceramic fiber blanket usually wins there. Where the question is how the forms are made rather than which one to buy — bulk as the feedstock, needling against vacuum forming — our ceramic fiber bulk, blanket and board structures guide covers the whole chain. Our comparison of blanket, board, paper and cloth forms walks through that decision form by form. For the cross-material view — where board, panel, tile and sheet sit across calcium silicate, rock wool, glass wool and ceramic fiber — see our insulation board and panel forms guide. See ceramic fiber cloth for the woven range. Ceramic Fiber Paper: Thin Gaskets, Parting Layers and Electrical Isolation Ceramic fiber paper is made by wet-laying a short-fiber slurry — no weave at all. It is thin, flat and dimensionally even, which is why it is the form used wherever a tight tolerance matters more than strength. Thickness typically runs 0.5–6 mm, with density controlled during manufacture. That combination makes ceramic fiber paper easy to die-cut into shaped gaskets, flange spacers, and precision shims, and it is the reason it appears in applications the other three forms cannot serve at all: thin electrical isolation between heating elements and their supports, parting layers between refractory sections, and backing for instrument probe assemblies. Its limitations follow directly from having no weave. Ceramic fiber paper has almost no tensile strength, so it cannot be wrapped, pulled or used where it carries any load. It softens and loses integrity when wet, which rules out damp locations unless it is protected. Where a paper gasket will see any movement or clamping load, it needs the adjacent metalwork to do the work rather than the paper itself. See ceramic fiber paper for thickness and density options. The Reinforcement Wire Is Usually the Weakest Link This is the point that catches experienced buyers, and it deserves its own section. The ceramic fiber itself is rated to 1,260 °C or more, but the wire threaded through it to give strength rarely is. Specify a ceramic fiber rope or tape by fiber grade alone and you can end up with a product whose reinforcement fails long before the fiber does. Reinforcement | Practical continuous limit | Notes | Glass filament | Up to about 650 °C | Above this the filament embrittles and loses all tensile contribution | Stainless steel wire | About 1,000–1,100 °C | The standard step-up; widely available and adequate for most furnace duties | High-nickel alloy wire | Highest of the three | Chosen where repeated thermal cycling causes creep; the most expensive option | Two practical rules follow. Below about 650 °C, glass filament reinforcement is usually sufficient and considerably cheaper, so specifying metal there is simply spending money for nothing. Above about 1,100 °C continuous, or wherever the seal cycles hard, metal reinforcement is not optional — and where cycling is severe, the high-nickel option earns its cost by resisting creep. Where a product has no reinforcement at all, say so in the enquiry. Unreinforced ceramic fiber cloth and paper are perfectly reasonable choices for static linings, and asking for them explicitly avoids paying for strength that will never be used. A Five-Step Selection Method Working the four forms into a repeatable decision prevents most mis-buys: - Measure the duty temperature at the seal line, not the furnace setpoint. Add at least 100 °C of margin, then select the fiber grade from the continuous use column. - Assess the atmosphere. Standard grades suit mildly acidic flue gas. Alkali-rich environments — glass and cement kilns especially — call for high-alumina fiber. No grade in this family should be placed in direct contact with molten metal. - Measure the geometry. Gap width for a rope, wrap circumference and width for tape, surface area and shape complexity for cloth, and tolerance and thickness for paper. This step produces the order dimensions. - Choose construction and reinforcement. Square braid for doors that open, round braid for grooves, ceramic fiber tape for cylindrical runs, ceramic fiber cloth for anything that will be sewn, ceramic fiber paper for anything thin. Then set the reinforcement to the temperature and cycling duty. - Confirm the surface treatment. Graphite impregnation where gas tightness matters, vermiculite where radiation does, foil facing where the wrap is exposed to radiant load. What to Put in Your Enquiry Nine lines in an enquiry remove nearly all ambiguity, and most suppliers will quote faster when they see them: - Form — rope, tape, cloth or paper - Fiber grade — common, standard, high-purity, high-alumina, zirconia, or low-biopersistence fiber - Dimensions — rope diameter; tape width × thickness; cloth width × thickness; paper thickness × density - Construction — for rope: twisted, square braided or round braided - Reinforcement — none, glass filament, stainless steel wire, or high-nickel alloy wire - Surface treatment — none, graphite impregnated, vermiculite impregnated, or foil faced - Units — per kilogram, per metre or per square metre - Acceptance criteria — permanent linear change after heating, shot content, thermal conductivity at the service temperature - Documentation — material test report, safety data sheet, and the national product standard or its ASTM equivalent that the product is declared to Line 9 is the one most often skipped, and it is the one that decides whether a delivery can be rejected. Ask for the standard before delivery rather than after a dispute. Acceptance Checks Before You Sign Off Four checks are quick to run and catch most non-conforming deliveries: - Permanent linear change after heating. A common requirement is 3.5 % or less after a defined soak — often quoted at 1,000 °C for 24 hours. Higher figures mean the product will shrink away from the joint in service. - Shot content. Roughly 12 % or less for standard fiber and 8 % or less for high-purity grades. High shot content makes cloth and tape dusty, uneven and weaker. - Thermal conductivity at service temperature. Ask for the value at the actual mean temperature rather than at ambient. - Visual inspection. No delamination, broken yarn runs or hard lumps. Ceramic fiber tape and ceramic fiber cloth must not have missing yarn runs, and ceramic fiber paper must be free of pinholes. Installation, Compression and Safe Handling Installation practice determines whether a correctly specified ceramic fiber rope performs. Three points matter most: Compression. A seal rope is normally compressed to 25–40 % of its free thickness. Under-compress and it leaks; over-compress and the fiber takes a permanent set, loses resilience and leaks after the first thermal cycle. Follow the sizing rules above rather than compressing to taste. First heat check. After the first thermal cycle, inspect every joint and wrap while the plant is cold. Ceramic fiber rope that has taken a permanent set, ceramic fiber tape whose overlaps have opened, and ceramic fiber cloth whose seams have pulled are all signs that the compression or the sizing was wrong, and they are far cheaper to correct before the second cycle than after it. Wet service. Insulation performance falls sharply once ceramic fiber is soaked. In permanently damp locations either specify a protective coating or choose a different material class, because no amount of careful installation recovers performance from wet fiber. Dust and handling. Cutting and abrading any product in this family releases airborne fiber. Work ventilated, wear a P100-class respirator, goggles, gloves and overalls, and collect offcuts rather than dry-sweeping them. Below roughly 900 °C, low-biopersistence fiber increasingly replaces traditional aluminosilicate because it reduces the cost of occupational protection; where the duty permits, ask for it in the enquiry rather than retrofitting it after a hygiene audit. Related Reading - Ceramic Fiber Rope — twisted, square braided and round braided constructions - Ceramic Fiber Tape — widths, thicknesses and foil-faced options - Ceramic Fiber Cloth — woven fabric for covers, curtains and liners - Ceramic Fiber Paper — thin gasket and parting-layer grades - Ceramic Fiber Blanket — the economical choice for flat panels - Ceramic Fiber Rope Sealing and Gasketing Applications - Ceramic Fiber Blanket vs Board vs Paper vs Cloth - Ceramic Fiber Bulk: Grades, Uses and Application - Ceramic Fiber Raw Materials and Manufacturing Process - High-Temperature Insulation Wool Temperature Ratings Manufacturer & Supplier of Ceramic Fiber Rope, Tape, Cloth & Paper When buyers search for a ceramic fiber manufacturer or a ceramic fiber tape manufacturer, what they are really qualifying is the mill's control of fibre diameter, shot content and the alumina-silica ratio across every form — rope, tape, cloth and paper — not just one product line. A trader can quote all four; only a producer controls the chemistry that sets the 1100–1430 °C service window. What a qualified ceramic fiber manufacturer provides - A single alumina-silica base stock spun into multiple forms, so rope, tape, cloth and paper share the same thermal and chemical behaviour - Documented density and thickness ranges for each form, with test reports from an accredited laboratory - ISO 9001 quality management, CE marking and SGS verification on the produced grades - Batch traceability from raw material to finished coil or roll Forms and where they are specified - Ceramic Fiber Tape — wrapped on pipe, valves and irregular runs up to 1430 °C - Ceramic Fiber Rope — braided and twisted seals for furnace and kiln doors - Ceramic Fiber Cloth — sewn blankets and removable covers for large surfaces - Ceramic Fiber Paper — thin gaskets, parting layers and electrical isolation For the full material overview, see the Ceramic Fiber Insulation hub. Why source from an established manufacturer Rosewool has produced ceramic fiber forms since 1982 and exports to 60+ countries across power, petrochemical, foundry and heat-treatment sectors. Because we run the fibre line ourselves, a refractory ceramic fiber manufacturer enquiry and a ceramic fiber cloth manufacturer or ceramic fiber paper manufacturer enquiry are answered from the same production batch — not three separate vendors. Contact our engineering team for density selection, thickness calculation and project-specific specifications. FAQ: Q: What is the difference between ceramic fiber rope and ceramic fiber tape? A: Ceramic fiber rope is braided or twisted into a round or square cross-section and is compressed into a joint to seal it, so it is chosen for gaps — furnace doors, manways, flanges and expansion joints. Ceramic fiber tape is woven flat, typically 20–150 mm wide and 1.5–6 mm thick, and is spiral-wrapped around cylindrical objects such as pipe, valve bodies and exhaust runs. Rope seals; tape wraps. Choose rope for a static joint you compress, and tape for a surface you cover. Q: What temperature can ceramic fiber rope withstand? A: The ceramic fiber itself is graded up to a 1,430 °C classification temperature with about 1,350 °C continuous use, but the reinforcement almost always governs the real answer. Glass filament reinforcement is limited to roughly 650 °C, stainless steel wire to about 1,000–1,100 °C, and high-nickel alloy wire is specified above that for severe cycling. State both the fiber grade and the reinforcement when you enquire, because a standard grade with glass filament reinforcement is a very different product from the same grade with metal reinforcement. Q: How do I size ceramic fiber rope for a gap? A: For a machined groove, use a free rope diameter of about 1.1 to 1.2 times the groove width so the rope fills the groove without forcing the joint apart. For an unconfined gap, use about 1.3 times the gap width, because the extra diameter provides the pre-compression a joint needs once it moves. At installation, compress a seal rope to 25–40 % of its free thickness — compressing further risks permanent set and loss of resilience after the first thermal cycle. Above roughly 25 mm diameter, specify metallic reinforcement to prevent slumping. Q: When should I choose ceramic fiber cloth over ceramic fiber blanket? A: Choose ceramic fiber cloth when the surface is complex enough that the material has to be cut and sewn to fit — removable insulation covers, fire curtains, expansion joint liners, and awkwardly shaped equipment. Cloth is also right where the insulation has to be opened and closed repeatedly. For a simple flat panel or a large plain run, ceramic fiber blanket is normally cheaper and installs faster, since it does not need sewing. Q: Is ceramic fiber paper suitable for gaskets? A: Yes, and it is one of its main uses. Ceramic fiber paper is wet-laid rather than woven, so it is flat, even and easy to die-cut into precise gasket shapes, typically from 0.5 to 6 mm thick. Its limits follow from that construction: it has almost no tensile strength, so it cannot be wrapped or loaded, and it softens when wet, so damp locations are unsuitable unless it is protected. The metalwork around it should carry clamping load rather than the paper itself. Q: What reinforcement should I specify for ceramic fiber rope or tape? A: Match the reinforcement to the duty temperature rather than buying the strongest option. Below about 650 °C, glass filament reinforcement is adequate and considerably cheaper. From there to roughly 1,100 °C, stainless steel wire is the standard step-up. Above that, or wherever repeated thermal cycling causes the joint to be compressed and released many times, high-nickel alloy wire resists creep better and holds resilience longer. If the product will be static and carry no load, unreinforced is a legitimate and economical choice — say so explicitly in the enquiry. Q: What should I check before accepting a ceramic fiber delivery? A: Four checks cover most failures. First, permanent linear change after heating — commonly 3.5 % or less after a defined soak, often 1,000 °C for 24 hours — since higher numbers mean the seal will shrink away from the joint. Second, shot content, roughly 12 % or less for standard fiber and 8 % or less for high-purity grades. Third, thermal conductivity quoted at the actual mean service temperature rather than at ambient. Fourth, a visual check for delamination, broken or missing yarn runs, hard lumps and, in paper, pinholes. Request the declared standard and test report in the enquiry so the delivery can be assessed against something. ### Euroclass Fire Classification for Industrial Insulation: A1 to F, Smoke and Droplet Levels Explained URL: https://www.rosetexwool.net/news/euroclass-fire-classification-insulation/ 2026-09-10 | Author: Rosetexwool Editorial | Category: industry insight Summary: The Euroclass system explained for industrial insulation — the seven main classes from A1 to F, the s1-s3 smoke and d0-d2 droplet suffixes, and the EN 13501-1 test methods behind them. Insulation fire class is one of the few specifications on a datasheet that carries legal weight. Under the European Construction Products Regulation, a construction product placed on the EU market must declare its reaction-to-fire performance using the Euroclass system defined in EN 13501-1. That declaration is not marketing copy — it is the evidence on which a building control authority accepts or rejects a specification, and increasingly the evidence on which an industrial buyer accepts or rejects a delivery. Yet the Euroclass code is widely misread. A specifier who asks for "A1" and nothing else has asked for half a fire classification. A buyer who accepts "B" without asking for the smoke and droplet suffixes has accepted a material that may be unlawful in the intended application. This guide explains the whole system — the seven main classes, the smoke and droplet suffixes, the test methods behind them, and how the code maps onto the insulation families used in industrial plant. For the A1-specific detail and the material-by-material comparison, see our A1 non-combustible insulation guide. Why Insulation Fire Class Has Become a Procurement Question, Not a Marketing Term Twenty years ago, fire performance was a line on a datasheet that few people read. Today the fire classification is a compliance document, and on many industrial projects it is the first thing an inspector asks to see. Three pressures produced that shift. First, the Construction Products Regulation made the declaration mandatory: a product covered by a harmonised European standard cannot carry CE marking for the EU market without a declared reaction-to-fire class, and that declaration has to appear on the Declaration of Performance. Second, insurers and lenders have followed the regulators — a plant whose insulation cannot be evidenced to the declared class is a plant that is difficult to insure. Third, the cost of getting it wrong has moved from the material to the schedule: stripping and replacing non-compliant insulation after handover costs multiples of the insulation itself, and it costs them at the worst possible moment. The practical consequence is that a competent industrial buyer now treats the fire classification as a testable specification rather than a claim. That means naming the class, the suffix, the standard and the evidence in the enquiry document. An enquiry that says "A1" tells a supplier what to.write on a label; an enquiry that says "A1 to EN 13501-1, with a current third-party certificate and a Declaration of Performance naming this product line" tells a supplier what will be checked at goods inward. The second version is the one that survives an audit. EN 13501-1: The Test Stack Behind the Euroclass Rating EN 13501-1 is a classification standard, not a test standard. It does not burn anything. It defines how the results of four separate test methods are converted into a class, and understanding those four tests is what turns a class from a label into a piece of evidence. EN ISO 1182 — non-combustibility. A small specimen is placed in a furnace at about 750 °C. The material passes if the temperature rise stays within 30 °C, the mass loss stays within 50 %, and there is no sustained flaming. This is the test that separates the non-combustible classes from everything below them. EN ISO 1716 — gross calorific potential. A sample is burned completely in a bomb calorimeter to measure its gross heat of combustion, written as PCS. Class A1 requires a PCS at or below 2.0 MJ/kg; class A2 allows up to 3.0 MJ/kg. This is the test that puts a number on how much energy the material could add to a fire, and it is the reason two materials that both look "non-combustible" can sit in different classes. EN 13823 — the Single Burning Item (SBI) test. A corner assembly of two vertical panels is exposed to a gas burner, and the test measures how fast the fire grows and how much heat and smoke the assembly releases. The outputs that matter are FIGRA, the fire growth rate index; THR600s, the total heat released in the first 600 seconds; LFS, lateral flame spread along the specimen; plus the smoke integral and any flaming droplets. Almost everything a specifier cares about below class A1 comes out of this one rig. EN ISO 11925-2 — small flame ignitability. A small flame is applied to the edge or the surface of a specimen for 15 or 30 seconds. It is a screening test, and for the lowest classes it is the only test that matters. The classes draw on these tests in a fixed pattern. A1 draws on EN ISO 1182 and EN ISO 1716. A2 draws on those two plus the SBI test. B, C and D draw on the SBI test plus the small flame test. E draws on the small flame test alone. F is not a test result at all — it means no performance has been determined. One route deserves a mention because it saves both time and money. The European Commission publishes classification-without-further-testing decisions for products whose performance is so well established that testing adds nothing. Mineral wool with an organic content at or below 1 % is the classic case: it is classified A1 on the basis of its composition, with no laboratory run. If a supplier quotes a mineral wool product as A1 under that route, that is legitimate — but the Declaration of Performance should still name the decision rather than simply asserting the class. The Seven Main Classes — A1, A2, B, C, D, E, F The Euroclass main class describes how much the material contributes to a fire in its early stage, and Euroclass A1 is the only class that carries no combustible contribution at any stage. The table below is the working summary used throughout the rest of this guide. Class | What it means | Tests behind it | Typical industrial insulation | Where it is used | A1 | No contribution to fire at any stage | EN ISO 1182 + EN ISO 1716 | Rock wool, glass wool, foam glass, calcium silicate | High-risk plant, chemical and pharmaceutical facilities, underground works, hospitals, escape routes | A2 | Almost no contribution; very limited combustible content | EN ISO 1182 or 1716 + EN 13823 | Modified PIR, inorganic composites | High-risk areas where A1 is uneconomic but s1,d0 is required | B | Combustible, very limited contribution | EN 13823 + EN ISO 11925-2 | Flame-retardant PIR, phenolic foam | Occupied industrial buildings, control rooms, data halls | C | Combustible, limited contribution | EN 13823 + EN ISO 11925-2 | Flame-retardant EPS and XPS, some PUR | Low-risk industrial buildings, warehouses | D | Combustible, moderate contribution | EN 13823 + EN ISO 11925-2 | PVC-based boards, some treated wood products | Low-risk plant rooms and equipment enclosures | E | Combustible, only briefly resistant to a small flame | EN ISO 11925-2 | Unmodified EPS and XPS | Heavily restricted; not a building insulation class | F | No performance determined | None | Untreated foam plastics | Not acceptable for insulation systems | The thresholds behind the combustible classes are worth knowing, because they are what a test report actually shows. Class B requires a FIGRA at or below 250 W/s, a THR600s at or below 7.5 MJ, lateral flame spread that does not reach the edge of the specimen, and no flaming droplets or particles that persist beyond the limit. Class C relaxes the heat-release limits while keeping the flame-spread and droplet requirements. Class D relaxes them further still. Where a quotation offers Euroclass F insulation, the honest reading is that no reaction-to-fire performance has been determined at all — not that the material failed a test. F is an absence of evidence, and an absence of evidence is not a specification. Smoke Classes s1, s2, s3 — What the SBI Smoke Integral Really Says The smoke class is appended to every class from A2 down to D, and it describes how much smoke the material produces during the SBI test. A1 is normally declared bare, because a material that does not burn produces no smoke worth measuring; where a project wants documented evidence, an A1-s1,d0 declaration can still be produced from an SBI run. s1 — the smoke integral stays at or below 750 %·min. Smoke production is low, and this is the class specified for escape routes, occupied process buildings and any space where people have to find their way out through smoke. s2 — smoke production falls between the s1 threshold and the s3 floor. Acceptable in ordinary industrial buildings with straightforward escape and low occupancy. s3 — no smoke requirement has been met. Smoke production is high enough to affect tenability, and in practice this restricts the material to unoccupied or very low-risk locations. The reason this matters more than most buyers expect is that in a real fire, smoke incapacitates long before flame reaches people. Two products can both be A2 and behave completely differently in a corridor: A2-s1,d0 keeps an escape route breathable, while A2-s3,d2 fills it. For data halls, hospital plant rooms, chemical control rooms and underground structures, s1 is not a nice-to-have — it is the requirement that makes the rest of the fire strategy work. Droplet Classes d0, d1, d2 — Why Dripping Disqualifies Vertical Systems The droplet class records what falls off a burning material, and in vertical applications it is the difference between a contained fire and a spreading one. d0 — no flaming droplets or particles appear within 600 seconds. This is the class that lets a system be installed without additional fire-stopping measures. d1 — some flaming droplets appear, but they stop burning within 10 seconds. The risk is lower, although vertical runs may still need a barrier. d2 — flaming droplets that burn for longer than 10 seconds. Burning droplets fall, carry the fire downward and ignite whatever sits below, which is why a d2 material is difficult to justify on any vertical surface. This is the mechanism behind what designers call the chimney effect. A C or D class material with a d2 rating installed on a vertical run can propagate fire along a cavity far faster than the material's own class suggests, because the droplets do the travelling rather than the flame front. Specifying d0 removes that path entirely, which is why systems written around A2-s1,d0 or B-s1,d0 frequently avoid the fire barriers a d2 build-up would demand. Material chemistry drives the result. Phenolic foam and PIR char rather than melt, which is why they commonly reach d0. Polystyrene melts and drips unless it is heavily modified, which is why unmodified EPS and XPS sit at E or F with d2 behaviour. How to Read a Euroclass Code: A2-s1, d0 and B-s1, d0 Decoded A Euroclass code has up to three parts: the main class, the smoke class and the droplet class. Reading it correctly is mostly a matter of knowing what is mandatory and what is optional. Euroclass A1 is declared on its own. No suffix is required, because a material that contributes nothing to a fire has no smoke or droplet performance to declare. Classes A2, B, C and D must carry both suffixes — a bare "A2" is an incomplete classification, and a supplier that quotes one has not finished the sentence. Class E is declared as E, or as E-d2 where droplets occur. Class F carries nothing. So the codes read like this: A1 — no contribution to fire, at any stage. A2-s1, d0 — almost no contribution to fire, low smoke, no flaming droplets. This is the class usually written where A1 is uneconomic but the risk tier still demands near non-combustible behaviour with documented smoke and droplet performance. B-s1, d0 — combustible, but with a very limited contribution to fire growth, low smoke and no flaming droplets. In a real escape route this material will frequently outperform an A2-s3,d2 product, because the thing that endangers people in the first ten minutes is smoke, not the main class. Buyers searching the term write it both as Euroclass A1 and as Euro class A1 — the classification is identical and the difference is only typographic, so a specification written either way means the same thing and should be answered with the same evidence. One further detail catches a lot of specifications out: the fire classification belongs to the tested build-up, not to the raw material. Where a code is written for a product that is installed as a composite — insulation plus facing plus adhesive — the classification applies to the build-up that was tested, not to the core material in isolation. A glass wool core that is A1 on its own can be downgraded by a polymer facing. The declaration has to name the composite. Insulation Family to Euroclass — A Working Map The table below maps the insulation families used in industrial plant onto the classes they realistically reach. Treat it as a starting shortlist: the binding number is always the one on the Declaration of Performance for the exact product and build-up quoted. Insulation family | Typical Euroclass | Why it lands there | Specification note | Rock wool | A1 | Melted mineral fibre with very low organic content; passes non-combustibility and calorific tests | The default for high-risk industrial work; confirm the binder content for the classification route | Glass wool (unfaced) | A1 | Same mineral-fibre logic as rock wool | A foil or polymer facing can downgrade the composite — check the glass wool fire rating for the full build-up | Foam glass / cellular glass | A1 | Closed-cell inorganic glass, no organic binder | Also impermeable and dimensionally stable, which is why it is used below grade and on cryogenic tank bases | Calcium silicate | A1 | Inorganic rigid board | Common on high-temperature pipe and equipment where fire class and temperature rating are both needed | Ceramic fibre | A1 | Inorganic alumino-silicate fibre | Specified for temperature rather than fire class, but declares A1 | Microporous and aerogel blanket | A2 to B, depending on build-up | The inorganic core is non-combustible; the reinforcing fibre and facing drive the class | Always read the declaration for the exact facing — the class moves with it | Phenolic foam | B-s1, d0 (some modified grades reach A2) | Chars rather than melts; very low smoke | Among the best fire performance of the organic foams | PIR | B-s1, d0 (high-performance grades reach A2-s1, d0) | Chars, does not melt or drip | Widely used where thickness is constrained and the risk tier permits a combustible class | PUR | B to C depending on formulation | Depends on the flame-retardant package | Ask for the class of the formulation quoted, not the family | EPS and XPS | E unmodified; C or D with flame retardant; some grades reach B | Melts and drips unless modified | Watch the droplet class — unmodified grades behave as d2 | Elastomeric foam pipe sections | Typically B-s1, d0 to C-s1, d0 | Flexible closed-cell rubber or plastics | Used on chilled and cold-water lines; check the pipe-specific classification | That last row raises the point that most specifications miss. EN 13501-1 classifies linear pipe insulation separately, with an L suffix appended to the class: A1L, A2L-s1,d0, BL-s1,d0 and so on down to EL and FL. The pipe classification uses a different fire scenario, because a cylindrical section on a small burner behaves nothing like a flat panel in a corner rig. A pipe insulation quoted to a flat-panel class has been quoted to the wrong test, and the insulation fire classification that a pipe specification needs is the one with the L on the end. Industrial Application Selector by Risk Tier Most projects do not need the highest Euroclass everywhere. What they need is the right class in the right place, which is a risk decision rather than a materials decision. Risk tier | Typical locations | Class to specify | Notes | High | Chemical and pharmaceutical plant, hazardous stores, underground structures, hospitals, escape routes, data halls | A1, or A2-s1,d0 | Smoke class s1 and droplet class d0 are both required, not optional | Medium | General factories, warehouses, logistics buildings, plant rooms with normal occupancy | A2-s1,d0, or B-s1,d0 | An organic foam is acceptable here, but only with s1 and d0 attached | Low | Simple storage sheds, temporary buildings, unmanned equipment enclosures | C-s1,d0, or D-s1,d0 | Fire barriers and compartmentation carry the strategy; verify the local code permits the class | Two rules cut across all three tiers. First, the composite must be classified, not the core — a facing, an adhesive or a mechanical fixing can change the result. Second, a multi-layer system is only as good as its weakest declared layer plus its detailing: a penetration that is not sealed to the same performance as the surrounding build-up is where the fire actually goes. For a material-by-material walk through the five industrial families — temperature band, form factor, fire class and lifetime cost — see the industrial pipe insulation materials selection guide. Common Procurement Mistakes in Fire-Class Specifications Specifying the main class only. Asking for "A2" without the suffixes is asking for an incomplete fire classification, because the standard requires A2 to be declared with a smoke and a droplet class. Write the full code. Assuming the test thickness is the installed thickness. The SBI rig has a practical limit on specimen thickness, and thicker products need a defined mounting method. If the product will be installed at a thickness beyond the tested range, the declaration does not automatically cover it — ask what was tested and how. Classifying the core instead of the composite. This is the most common failure on site. The core may be A1 while the facing is not, and the finished product carries the lower class. Insist on a declaration that names the build-up being supplied. Accepting a supplier datasheet in place of a declaration. A datasheet is a marketing document. The documents that carry weight are the Declaration of Performance and the CE marking that accompanies it, backed by a test report from an accredited laboratory. Check that the certificate covers the product line quoted, and check the date. Forgetting the pipe classification. Flat-panel classes and pipe classes are different tests with different suffixes. Pipe insulation needs the L classification. Transferring a class between product forms. A board and a blanket made from the same base material can land in different classes, because the binder content, the density and the facing all differ. The class belongs to the product that was tested. Euroclass, ASTM E84, IMO FTP — How the Standards Cross-Reference Industrial projects often span more than one regulatory regime, and the three systems that come up most are frequently confused with each other. The most important thing to understand is that they answer different questions. Euroclass, under EN 13501-1, is a reaction-to-fire classification. It asks how much the material itself contributes to a developing fire. ASTM E84, used in North America, is also a reaction-to-fire test, and reports a flame spread index and a smoke developed index that are grouped into Class A, Class B and Class C. The IMO FTP Code, applied under SOLAS to ships and offshore installations, is different again: codes such as A-60 describe fire resistance — how long a complete assembly holds back a fire, keeps its integrity and limits the temperature rise on the unexposed side. A reaction-to-fire class and a fire-resistance rating are not interchangeable, and no table can make them equivalent. The approximate comparison below is a translation aid, not a legal substitution. Question | Euroclass (EN 13501-1) | ASTM E84 | IMO FTP Code | What it measures | Contribution of the material to fire growth, smoke and droplets | Surface flame spread and smoke developed | Time an assembly resists a standard fire curve | Typical output | A1, A2-s1,d0, B-s1,d0, C-s1,d0 | Class A, B or C | A-60, A-30, H-120, H-60 | Rough correspondence | Euroclass A1 and A2 sit at the top | Class A (flame spread index at the low end) | Not comparable — different test object | Applies to | Products placed on the EU market | Products in North American projects | Marine and offshore assemblies | Several national systems outside Europe use a similar A and B lettering, including the Chinese national classification for building products. The letters look familiar, but the test methods and the thresholds are not the same, and a class in one system does not carry over to another without testing. For the marine and offshore regime in detail, including what an A-60 rating actually requires and how it is certified, see the marine and offshore fire insulation standards guide, and for the rating itself, A-60 marine insulation explained. Related Reading The Euroclass system is not difficult, but it rewards precision: name the main class, name both suffixes for anything below A1, name the standard, and ask for the evidence that matches the build-up being supplied. Do that and the fire classification stops being a line on a datasheet and becomes what it was always meant to be — a checkable statement about how a material behaves in the first ten minutes of a fire. Three follow-ups cover the ground this guide only summarises: - A1 non-combustible insulation systems and the material comparison — the A1 class in depth, with the materials that reach it - Is glass wool fireproof? — the A1 rating of glass wool, and when a facing changes the answer - A1 vs A2 vs B fire rating — decision-focused comparison of the three most common specification bands - Industrial pipe insulation materials — the five families compared by temperature, form and fire class FAQ: Q: Is the Euroclass system used outside Europe? A: The Euroclass system is the European declaration route under the Construction Products Regulation, but it is widely referenced in projects outside the EU because the test evidence is well understood. Several national systems elsewhere, including the Chinese national classification for building products, use a broadly similar A and B lettering. The letters are not equivalent, however, and a class in one system does not transfer to another without testing to that system's own methods. Q: What is the difference between A1 and non-combustible? A: A1 is the class; non-combustible is what it means in practice. To reach A1 under EN 13501-1 a material must pass the non-combustibility test, EN ISO 1182, and stay within a gross calorific potential of 2.0 MJ/kg under EN ISO 1716. Materials described simply as non-combustible without a class, a standard and a test report are making a claim rather than declaring a classification, and the claim is not checkable at goods inward. Q: What do s1 and d0 mean in a Euroclass code? A: s1 is the lowest smoke class: the smoke integral measured in the SBI test stays at or below 750 %·min, which keeps an escape route tenable. d0 is the best droplet class: no flaming droplets or particles appear within 600 seconds, so the material cannot carry fire downward. Together they are what makes A2-s1,d0 or B-s1,d0 usable in occupied and high-risk locations, and they are mandatory suffixes for every class from A2 down to D. Q: Does thickness change the fire classification of insulation? A: It can. The SBI test has a practical limit on specimen thickness, and a product installed thicker than the tested build-up is not automatically covered by that declaration. Ask what thickness was tested and by what mounting method, and if the installed thickness exceeds it, ask for evidence that covers the installed condition rather than assuming the class carries over. Q: How is a composite insulation system classified? A: The classification applies to the build-up that was tested, not to the core material in isolation. An insulation core that is A1 on its own can be downgraded by a polymer facing, an adhesive or a fixing system. Insist that the Declaration of Performance names the complete composite being supplied, including facing and adhesive, and check that the certificate covers that product line rather than a similar one. Q: How does Euroclass A1 compare with ASTM E84 Class A? A: Both relate to reaction to fire, but they are different tests producing different kinds of result. Euroclass A1 is a classification built on non-combustibility and calorific tests; ASTM E84 reports a flame spread index and a smoke developed index grouped into Class A, B or C. A1 and A2 sit at the top of the Euroclass scale and broadly correspond to the best ASTM E84 performance, but there is no legal equivalence and a substitution always has to be supported by testing to the standard named in the specification. Q: What four steps settle an insulation fire-class specification? A: First, fix the risk tier of the location and the class that follows from it, including whether s1 and d0 are required. Second, write the complete code with both suffixes, plus the standard and the year. Third, require the evidence: a Declaration of Performance, CE marking where it applies, and a test report from an accredited laboratory naming the exact product and build-up. Fourth, check it at delivery — the certificate should match the product line on the pallet, not a similar one from the same factory. ### Glass Wool Insulation Buyer's Guide 2026: Supplier, Density and Specification Selection URL: https://www.rosetexwool.net/news/glass-wool-insulation-buyers-guide-2026/ 2026-09-09 | Author: Rosetexwool Editorial | Category: industry insight Summary: Supplier audit, formaldehyde-free selection, density selection and an enquiry checklist — the four decisions that settle an industrial glass wool insulation purchase. Insulating an industrial plant is not one purchase repeated across the building. The blanket wrapped around a steam header, the rigid board in a clean-room ceiling and the acoustic layer inside a partition wall are three different specifications, and the material that is correct on one is frequently wrong on the next. This guide is written for engineers, procurement teams and project buyers who have to source industrial glass wool insulation and want to buy it once, correctly. It walks through the four decisions that settle a glass wool insulation enquiry — supplier audit, formaldehyde-free performance, density selection and the specification checklist — and ends with the working tables and the questions that stop most disputes before they start. For the roll-format detail of the most commonly ordered form, see our glass wool blanket specification detail. Why Glass Wool Buyer Selection Has Become a System, Not a Spec Comparison Twenty years ago a glass wool insulation purchase was a density and a thickness set against a price. It is no longer that simple. Three pressures have turned glass wool insulation procurement into a system. First, project specifications now attach to certificates, not just numbers — an A1 fire rating, a formaldehyde-emission limit and a lot-level test report have become the difference between a quote and a pass. Second, the cost of a bad batch has moved from material to schedule: rework, hold points and re-testing cost more than the wool itself. Third, environmental and indoor-air requirements keep tightening, so a supplier that cannot document its binder chemistry is increasingly a liability. The result is that a competent glass wool buyer now audits a supplier the way they audit a contractor — on evidence, consistency and response time — rather than on a datasheet headline. That shift is what separates a careful glass wool buyer from a price shopper, and it is the subject of the rest of this guide. The Four Decision Dimensions That Settle a Glass Wool Enquiry Every glass wool insulation enquiry — whether the buyer writes the term glass wool or glasswool — resolves into four questions. Get these four right and the rest is quotation arithmetic. Supplier integrity — can the manufacturer document what it makes, and will the batch you receive match the sample you approved? Formaldehyde-free performance — is the binder chemistry suitable for the space, and can the emission level be certified? Density selection — is the density right for the service temperature, the mechanical load and the environment? Specification completeness — does the enquiry checklist capture the parameters, certificates, acceptance criteria and warranty that stop disputes? The four dimensions interlock. A strong supplier cannot rescue a wrong density, and a perfect density cannot rescue a specification that never stated the acceptance tolerance. This guide treats them in that order. Supplier Audit: From Documentary Evidence to Real Consistency A supplier audit for glass wool insulation has two layers: documentary evidence and production consistency. The first is checkable in an afternoon; the second is what separates a reliable manufacturer from a trader. Documentary evidence. Ask for the current certificates and read the scope. The fire classification should be A1 non-combustible. The quality system should be a recognised ISO 9001 framework, and the product should carry third-party test reports — preferably from an accredited laboratory — covering density, thermal conductivity, fibre diameter and shot content. A certificate that is out of date, or that covers a different product line than the one quoted, is a warning sign. Production consistency. This is the part most buyers skip, and it is where a large share of project problems originate. Three numbers reveal it. Density deviation should be held within about ±3 % to ±5 % — better than the ±10 % many standards allow — because density drift of even a few points changes both thermal and acoustic performance. Fibre diameter should sit at or below 8 µm, and shot content (unfiberised particles) at or below 3 %. Ask for lot-level data across recent production runs, not a single "typical" value. Service response. Confirm the manufacturer can do more than ship. A competent glass wool supplier can advise on density for a given service temperature, offer density-gradient or special-size cutting, and answer a technical question within a working day. Delivery lead time is part of the specification — write it down, and build the consequence for missing it into the contract. Whether the enquiry is phrased as a glass wool or glasswool insulation manufacturer search, the audit is the same. For the manufacturing process behind those consistency numbers, see our centrifugal glass wool manufacturing guide. Regional Supplier Profiles: What Each Manufacturing Cluster Is Known For Industrial glass wool insulation production clusters around a few manufacturing regions, and each cluster has a recognisable character. Knowing it helps you match a supplier to a project rather than to a price. A northern manufacturing cluster is known for speed and scale. High-volume production, dense logistics networks and short lead times make it the natural choice for pipe insulation and standard-duty blankets on fast-moving industrial projects. Expect density control in the ±3 % range and the ability to run density-gradient and special-size orders. A coastal cluster is known for lightweight, low-emission products. Manufacturers here have invested in fine-fibre and low-VOC binder technology, which makes them the default for clean rooms, medical spaces and precision manufacturing where indoor air quality governs. A southern coastal cluster is known for moisture performance. Products aimed at hot, humid conditions carry higher water repellency and facing options, which matters for coastal plants, HVAC systems and any service where condensation is a threat. A high-altitude cluster and a cold-region cluster specialise in the extremes — stable acoustic performance at altitude, and low-temperature, sand-resistant grades for severe winter and desert duty. None of this is a rule; it is a starting bias. The audit in the previous section decides the shortlist, and the cluster character decides which shortlist is worth the freight cost for your site. Formaldehyde-Free Glass Wool: Binders, Certifications and Project Fit Formaldehyde-free glass wool has moved from a premium option to a near-default requirement in anything that touches people or sensitive process air. The chemistry. Traditional glass wool uses a phenolic resin binder, which can release trace formaldehyde. Formaldehyde-free grades replace it with a plant-based, bio-based or silica-based binder that cures at roughly 150–250 °C for about five minutes, leaving no formaldehyde in the finished product. The wool itself is the same; the binder is what changes. Why it matters. Formaldehyde-free material removes a health and indoor-air liability, carries no odour during installation, ages more stably in hot-humid service, and makes green-building certification (such as LEED or WELL) easier to achieve. In clean rooms, food and pharmaceutical plants, electronics factories, hospitals and laboratories it is increasingly a written requirement rather than a preference. Certification to ask for. Ask for the emission test method and the limit. A common benchmark is a formaldehyde release at or below 0.05 mg/m³ under a climate-chamber method, with TVOC release at or below 0.5 mg/m³ for the most demanding spaces. Request the test report, check the laboratory is accredited, and confirm the value applies to the product you are actually buying — not a sibling line. For the fire side of the same material, see our glass wool A1 non-combustible rating guide. Density Selection: A Working Table by Service Condition Density is the single parameter that most decides whether glass wool insulation performs, holds its shape and lasts. A useful starting rule: every 100 °C rise in continuous service temperature calls for roughly 8 kg/m³ more density. Density matters for three reasons at once. It sets thermal and acoustic performance, it sets compressive strength and sag resistance, and it sets long-term dimensional stability — a higher-density board keeps its thermal resistance longer under load and temperature. The table below is a working selector across the common industrial conditions. All values sit within the 10–100 kg/m³ range in which glass wool is manufactured, and the temperature column respects the material's continuous ceiling. Service condition | Density range (kg/m³) | Key selection factors | Hot pipe insulation | 64–96 | Continuous temperature up to 350 °C, thermal-shock resistance, structural stability | Cold pipe insulation | 32–48 | Light weight, moisture resistance, ease of installation | Plant building envelope | 48–64 | Wind load, rain ingress, long-term thermal-resistance stability | Clean-room ceiling | 32–48 | Low dust release, easy cleaning, HVAC compatibility | Mechanical / acoustic partition | 80–100 | High density for sound isolation, NRC ≥ 0.95, low vibration transfer | Damp or below-grade service | 40–52 | High water repellency, freeze-thaw resistance, mould resistance | A note on the temperature ceiling. Glass wool is an A1 non-combustible material, but its binder limits continuous service to about 350 °C, with short peaks to 400 °C. Above that ceiling the specification moves to rock wool, which carries the higher temperatures. Stating the boundary cleanly avoids the classic error of putting a standard glass wool blanket on a line it cannot survive. For the form-by-form trade-off, see our glass wool vs rock wool comparison. Density-gradient construction. Where cost matters as much as performance, an outer low-density layer (around 32 kg/m³) over an inner high-density layer (around 48 kg/m³) meets the thermal requirement at a lower overall cost than a single high-density fill. Density is one axis of the decision; form is the other. Our glass wool board vs blanket vs batt comparison covers which form suits which surface before density is even considered. Specification Parameters That Catch a Bad Batch Before Installation The parameters below are what a buyer should put in writing, because they are the ones a bad batch fails. Each is measurable, and each has a reasonable acceptance number. Density and density deviation. State the nominal density and the tolerance — within ±5 % is a reasonable commercial requirement, tighter than the ±10 % many national standards allow. Verify on arrival by weighing a cut sample of known volume. Thickness tolerance. Specify the thickness and its tolerance; ±1.5 mm is normal, with ±0.5 mm achievable for precision work. Fibre diameter. At or below 8 µm is the general requirement; 5 µm and below is the premium grade that improves both conductivity and handleability. Shot content. At or below 3 % — a higher shot count means coarser fibre, worse conductivity and more dust. Thermal conductivity. Accept a declared value of 0.036 W/(m·K) or better at 25 °C for most industrial work, understanding that the number rises with temperature. Ask for the curve, not a single point. Water repellency. For humid or exposed service, specify a water-repellency rating of 98 % or better, rising to 99 % for high-humidity or below-grade duty. Emission limits. For formaldehyde-free requirements, state the release limit (typically ≤0.05 mg/m³) and the TVOC limit (≤0.5 mg/m³) where it applies. The Enquiry Checklist: Eleven Sections That Block Most Disputes A structured enquiry checklist is the cheapest dispute-avoidance tool in procurement. A large share of project problems trace to an enquiry that was never specific enough to enforce. The eleven sections below cover the ground. Copy them into the enquiry and fill in every blank — an empty box is the dispute waiting to happen. - Project basics — project name, location, scale, technical requirement and expected delivery date. - Product type — board, blanket, roll or other, stated explicitly. - Nominal density and tolerance — for example "48 kg/m³, measured not below 43.2 kg/m³". - Thickness and size with tolerance — thickness in mm and sheet dimensions in mm, each with a stated deviation. - Surface treatment — none, single-sided glass cloth, double-sided aluminium foil, PE film or other facing. - Thermal conductivity — the declared value at 25 °C, and the curve across the service range if it matters. - Water repellency — the minimum percentage, where the environment calls for it. - Emission limits — formaldehyde and TVOC where formaldehyde-free material is required. - Fire performance — A1 non-combustible, with the certificate number. - Certificates — ISO 9001, third-party test reports, and any industry-access qualifications required. - Acceptance, warranty and terms — acceptance window, warranty period, response time, retention ratio and the penalty for late delivery. Two acceptance rules complete the picture. Inspect appearance, dimensions and thickness within 48 hours of arrival, and complete performance sampling within 72 hours. If the density deviates more than the agreed tolerance, or the conductivity or emission limit is exceeded, reject the lot — do not negotiate it down. Whole-Life Cost: Why the Cheapest Quote Is Rarely the Cheapest Project The lowest unit price is a good place to start a negotiation and a poor place to end a decision. Industrial glass wool insulation is judged over the life of the plant, not the life of the invoice. Four cost buckets decide the real number. Initial cost is material, freight and installation. Operating cost is the energy the insulation saves or leaks over its life — a few points of conductivity difference compounds for years. Maintenance cost is replacement and repair when the material ages or fails. Hidden cost is the rework, schedule delay and re-testing when a batch fails acceptance or a certificate is missing. Two levers keep whole-life cost down. The density-gradient construction already described cuts initial cost without cutting performance. And selecting a higher-density grade pays back in service life — as a rough guide, each 8 kg/m³ step in density adds about five years of stable performance, which has to be weighed against the higher first cost. A supplier that offers a strategic, volume-based relationship with technical support is usually worth more than the lowest spot quote, because the support and the consistency are exactly what prevent the hidden-cost bucket from filling up. Common Mistakes in Industrial Glass Wool Procurement Four mistakes account for most failed glass wool purchases. They are easy to make and easy to avoid. "Thicker is better." Adding thickness without density does little for performance — a 60 mm board at 24 kg/m³ can underperform a 30 mm board at 48 kg/m³. Performance follows density and conductivity, not thickness alone. "Fire-resistant means it cannot smoke." Glass wool itself is A1 non-combustible, but a phenolic binder can char and smoke at high temperature. If smoke behaviour matters, specify a formaldehyde-free or otherwise low-smoke binder, and a suitable facing. "Good acoustics means good insulation." The two are controlled by different parameters. Low-frequency sound absorption needs thickness and density working together, while thermal performance follows conductivity. A material can be excellent at one and average at the other. "The lowest price saves money." A low price can hide recycled glass feedstock, short and brittle fibre, poor resilience and a supplier with no technical response. The savings disappear into rework, replacement and downtime. Judge the whole-life cost, not the invoice line. Closing Industrial glass wool insulation procurement is a system of four decisions. Audit the supplier on evidence and consistency, not a datasheet headline. Demand formaldehyde-free binder chemistry and its certificate wherever people or sensitive air are involved. Select density against service temperature, load and environment, using the working table rather than a guess. And run the enquiry through an eleven-section checklist that makes every tolerance, certificate and penalty enforceable. Buy once, correctly. Send us the service condition, the density or temperature requirement, the surface treatment and the annual volume, and our engineers will return a material recommendation, a specification schedule and a quotation — with lot-level test certificates — within two weeks. For the acoustic specification that often accompanies a glass wool insulation purchase, see our NRC and αw in glass wool partitions guide. Manufacturer & Supplier: Rosewool Glass Wool Capacity & Certifications Beyond the supplier audit, the fastest way to qualify a glass wool manufacturer is to confirm it runs the fibre line and can ship the exact density and facing you need. A glass wool board manufacturer and a glass wool insulation supplier should provide the same mill-direct traceability, not a traded assortment. Glass wool products we manufacture - Glass Wool Board — rigid panels for HVAC, duct and equipment insulation - Glass Wool Blanket — roll stock for large-surface and cavity applications - Glass Wool Insulation hub for densities, facings and project data Rosewool also supplies formaldehyde-free glass wool grades with low-VOC binders, certified to A1 non-combustible and produced under ISO 9001, CE and SGS frameworks. We have manufactured glass wool and exported to 60+ countries since 1982; contact our team for density selection and facing specifications. FAQ: Q: How do I choose the right density for glass wool insulation? A: Match density to the service condition rather than to habit. Hot pipe insulation typically needs 64–96 kg/m³, cold pipe and clean-room ceilings 32–48 kg/m³, plant building envelopes 48–64 kg/m³, mechanical and acoustic partitions 80–100 kg/m³, and damp or below-grade service 40–52 kg/m³. A useful starting rule is roughly 8 kg/m³ more density for every 100 °C rise in continuous service temperature. Q: How can I tell whether glass wool is genuinely formaldehyde-free? A: Ask for the binder chemistry and the emission test report, not just the marketing claim. A reliable formaldehyde-free grade uses a plant-based, bio-based or silica-based binder and carries a release at or below 0.05 mg/m³ under a climate-chamber method, with TVOC at or below 0.5 mg/m³ for the most demanding spaces. Check that the report comes from an accredited laboratory and applies to the exact product quoted. Q: What should a glass wool enquiry checklist include? A: An eleven-section checklist: project basics, product type, nominal density and tolerance, thickness and size with tolerance, surface treatment, thermal conductivity, water repellency, emission limits, fire performance, certificates, and acceptance plus warranty terms. Stating the density tolerance (for example within ±5 %) and the acceptance window is what makes the specification enforceable rather than aspirational. Q: Does the supplier's region matter when buying glass wool? A: Region is a starting bias, not a rule. A northern manufacturing cluster is known for speed and scale, a coastal cluster for low-emission lightweight products, a southern coastal cluster for moisture performance, and high-altitude and cold-region clusters for acoustic stability and severe-weather grades. The documentary and consistency audit decides the shortlist; the cluster character decides which shortlist is worth the freight cost. Q: What thermal conductivity should I accept in a glass wool quotation? A: For most industrial work, accept a declared value of 0.036 W/(m·K) or better at 25 °C, and ask for the curve across the service range rather than a single ambient point, because conductivity rises with temperature. A higher-density or finer-fibre grade will return a lower figure, and the saving compounds over the operating life. Q: When should I reject a glass wool delivery? A: Reject the lot when a measurable parameter fails the agreed tolerance — for example density deviation beyond the stated limit, conductivity above the accepted value, or an emission limit exceeded. Inspect appearance, dimensions and thickness within 48 hours of arrival and complete performance sampling within 72 hours. A parameter failure is a reason to reject, not to negotiate the batch down. Q: What warranty and after-sales terms should I ask for? A: Ask for a warranty of at least 12 months, a quality-issue response time within 24 hours, a clear defective-product replacement commitment, and a quality retention ratio of at least 5 % where the project scale justifies it. The contract should also fix the delivery lead time and the penalty for missing it, because schedule is part of the specification. ### Petrochemical Plant Insulation: Materials, Selection and Standards by Process Unit URL: https://www.rosetexwool.net/news/petrochemical-plant-insulation-guide/ 2026-09-09 | Author: Rosetexwool Editorial | Category: industry insight Summary: A unit-by-unit guide to petrochemical plant insulation — distillation, cracking, storage and heat-traced lines — with the temperature bands and corrosion regimes that decide material selection. Insulating a refinery or petrochemical complex is not one specification repeated across the site, and refinery insulation rarely transfers from one unit to the next. A crude distillation column, an ethylene cracking furnace, a process reactor, an LNG storage tank and a heat-traced instrument line impose almost nothing in common beyond a fire rating, and the material that is correct on one of them is frequently wrong on the next. This guide is written for engineers and buyers who have to specify petrochemical plant insulation across all four. It works unit by unit, gives the temperature band and the corrosion regime that actually governs each one, and ends with the thickness and structure rules that current standards require. For the material landscape as a whole, see our top 10 high-temperature insulation materials guide. What Petrochemical Plant Insulation Has to Do Four requirements separate petrochemical insulation from general industrial work. Fire performance is not negotiable. Hydrocarbon service means the insulation on hot lines and vessels is expected to be non-combustible. A1 or A-grade material is the default across virtually every high-temperature and flammable-media application on site, and combustible organic foam is confined to cold service where its low conductivity is worth the fire-engineering cost. Corrosion under insulation (CUI) is usually the dominant lifecycle risk. Water that reaches a warm steel surface under a jacket stays there. The result is a failure mode that is invisible until the insulation is stripped. Material selection, vapour retarders and jacketing detail matter more here than a few points of conductivity. Temperature range is extreme and discontinuous. One site spans about -165 °C on cryogenic storage to 1 300 °C in a cracking furnace radiant section, with almost nothing in between on many units. No single material covers that span. Access is expensive. Scaffolding, stripping and reinstatement routinely cost several times the material. That is what makes service life and inspectability a first-order economic input rather than an afterthought. The Four Material Families at a Glance Petrochemical specifications draw on four families. The table below gives the working ranges used across the industry. Family | Service range | Fire class | Conductivity | Where it is used | Rock wool | -200 to 650 °C | A1 / A | 0.032–0.060 W/(m·K) | Hot pipework, vessels, columns, general refinery duty | Ceramic fibre (aluminium silicate) | -200 to 1 400 °C | A1 / A | 0.030–0.035 W/(m·K) | Cracking furnaces, reformers, reactors, high-temperature piping | Glass wool | -120 to 400 °C | A1 / A | 0.032–0.040 W/(m·K) | Low-temperature lines, acoustic and HVAC duty | Calcium silicate | -200 to 650 °C | A1 / A | 0.040–0.050 W/(m·K) | Load-bearing hot equipment, pipe supports, fire-rated panels | Aerogel composite | -200 to 650 °C | A | 0.015–0.025 W/(m·K) | Space-constrained hot lines, valves, flanges, irregular geometry | Foam glass | -196 to 100 °C | A1 | 0.040–0.060 W/(m·K) | Cryogenic storage, buried and fully immersed service | Closed-cell elastomeric | -40 to 105 °C | B1 | 0.032–0.040 W/(m·K) | Cold and chilled water, low-temperature traced lines | The inorganic families — rock wool, ceramic fibre, glass wool and calcium silicate — carry the bulk of petrochemical plant insulation because they are non-combustible, chemically stable against process fluids and dimensionally stable through thermal cycling. Organic foams and elastomerics appear where they must: low-temperature and cold service. Aerogel composite has moved from a specialist item to a routine choice where clearance is the binding constraint. For a material-by-material walkthrough of the family that carries most refinery hot pipework, see our rock wool for petrochemical and refining insulation guide. Distillation Units: 150 to 420 °C with Two Corrosion Regimes A crude or vacuum column is the clearest example of one piece of equipment needing two insulation approaches. Temperature distribution. Atmospheric distillation runs roughly 150–200 °C at the column overhead and 360–370 °C at the column bottom. Vacuum distillation, operated under reduced pressure specifically to suppress thermal cracking of heavy fractions, runs about 300–420 °C. Two distinct corrosion mechanisms. The overhead condensing system carries an HCl–H₂S–H₂O environment with a condensate pH that can reach 1.0–1.3 — strongly acidic, and aggressive to both carbon steel and austenitic stainless. The column bottom carries a completely different problem: sulphidic corrosion when running high-sulphur crudes and naphthenic acid corrosion when running high-acid crudes. Naphthenic acid attack does not begin below about 220 °C, peaks at roughly 270–280 °C, and effectively ceases above 400 °C. What that means for insulation. The overhead circuit is where CUI starts, because it is cool enough to condense water and acidic enough to attack steel quickly. Insulation here has to be paired with a vapour retarder and a coating system specified for wet service, not simply chosen on conductivity. The bottom circuit is hot enough that water does not persist, so the driver becomes thermal performance and mechanical stability at 360–420 °C. Material selection. Glass wool and composite silicate suit overhead duty in the 150–200 °C band. Rock wool, ceramic fibre and calcium silicate carry the 360–420 °C bottom circuit. Phase-change zones — the initial condensation region where the vapour first liquefies — are the most aggressive locations on the column and deserve the most attention in both coating and insulation detail. Typical economic thickness runs 30–100 mm on the low-temperature circuit and 50–150 mm on the hot circuit. Both are calculated, not assumed, and both need a dew-point check on the cold side. Cracking and Reformer Furnaces: 600 to 1 300 °C and Thermal Shock Ethylene cracking and catalytic reforming are the two most demanding furnace insulation duties on a typical petrochemical site. Temperature distribution. Cracking furnace radiant sections operate at 600–1 300 °C, and decoking pushes tube metal to around 1 400 °C. Ultra-high-pressure steam lines leaving the transfer line exchanger are designed for roughly 520 °C at about 11 MPa. Thermal shock is the governing problem in furnace and reactor insulation. The cracking and decoking cycle swings tube temperature substantially and quickly — shutdown can drop tube temperature by 50–80 °C per hour. That cycling produces thermal fatigue in both the refractory and the tube supports, and it is the reason thermal shock resistance, not just temperature rating, selects the material for furnace insulation. Coke deposition creates a second mechanical problem. Coke and the underlying alloy expand at different rates, generating stress at the interface and spalling refractory if the lining is not designed for it. Material selection. Ceramic fibre — aluminium silicate — is the standard answer in the 1 000–1 400 °C band: low thermal mass, good thermal stability and low linear shrinkage, which is what makes it survive cycling. Alumina fibre extends to 1 600–2 000 °C for genuinely extreme positions. On the ultra-high-pressure steam lines at 520 °C and 11 MPa, rock wool, ceramic fibre and aerogel composite all appear; aerogel is chosen where clearance or weight is constrained, and the others where first cost governs. Thickness on furnace walls usually lands at 80–120 mm by heat-loss calculation, more in the hottest zones. On steam piping above 80 mm, the standards require the insulation to be built up in layers rather than as a single thickness — a rule that exists because a single thick layer compacts and slumps. What each unit actually demands of those numbers is set out in our unit-by-unit guide to refinery and reformer insulation, from CDU columns to SRU dew points. For the pipe-side detail, including pre-formed sections and density selection, see our rock wool pipe insulation specification and selection guide. Storage Tanks: LNG Cryogenic Through Ambient Crude Storage spans the widest temperature range of any unit on site, and the two ends need completely different systems. LNG and cryogenic storage, about -165 °C. The insulation has to hold boil-off to a very low rate — published operating data for large cryogenic tanks puts this in the region of 0.025 % per day — and it has to do so while the tank shell contracts. Two properties govern: the material must not shrink more than about 0.5 % at service temperature, and its bond strength to the substrate must stay above roughly 0.05 MPa. Foam glass, nanoporous aerogel composite and high-density polyisocyanurate are the standard answers. Cold-insulation thickness typically lands at 150–200 mm, and the outer surface must be held at or above ambient dew point — usually taken as dew point plus 1–3 °C — or the system will sweat, ice and fail. Crude and product tanks, ambient to moderate temperature. Here the governing requirement is fire performance, not thermal: A-grade non-combustible material, compatible with the tank's explosion-protection and earthing design. Rock wool, glass wool and composite silicate all serve. Thickness responds mostly to climate — roughly 70–100 mm in cold regions and 50–70 mm in temperate ones. Vapour control is common to both. Water absorption is normally held to 1.0 % or below, and the oxygen index of any organic component is normally specified at 30 or above. Where the tank shell is austenitic stainless, the insulation and any cement or mastic touching it have to meet the chloride, fluoride, silicate and sodium limits set out for austenitic stainless surfaces. For cryogenic pipework connecting into tankage, see our cryogenic pipe insulation guide. Heat-Trace and Traced Lines: -40 to +400 °C Traced lines are where most of the insulation volume on a site actually sits, and where the specification is most often generic. Temperature split. Low-temperature trace runs about -40 to 105 °C on instrument air, cooling water and similar services. High-temperature trace extends to roughly 400 °C where the line has to maintain process temperature. Three requirements dominate. Flexibility, because traced lines move, vibrate and are repeatedly stripped for maintenance. Water resistance, because cold traced lines condense and a wet insulation system is a CUI site as much as a hot one. And conformability, because the difficult parts of a traced system are not the straight runs — they are valves, elbows and flanges. Material selection. Closed-cell elastomeric insulation is the low-temperature default: it stays flexible at -40 °C with elastic recovery above 90 %, and its closed-cell structure is inherently water-resistant. Above about 100 °C, ceramic fibre and composite silicate take over. On irregular components — valve bodies, flanges, orifice plates — aerogel-based coating or ceramic fibre needled blanket is the practical answer, because a brushed or sprayed coating covers a flange with no joints and no leak paths, while a blanket can be cut and pinned to shape. Thickness is usually 30–100 mm by heat-loss calculation on low-temperature trace and 80–120 mm on hot trace, with the trace power and the ambient design condition both entering the calculation. Getting the Thickness and the Structure Right Three standards shape the calculation, and recent revisions have materially tightened what is acceptable. Thickness is calculated, not tabulated. Three methods are in normal use. The economic thickness method balances the cost of heat loss against the cost of insulation and is the usual basis for hot service. The surface temperature method is used where the constraint is personnel protection or condensation control. The heat balance method is used where the requirement is to delay freezing or to hold a defined rate of temperature drop. The limits have tightened. The 2024 revision of the general national standard for equipment and pipe insulation cut allowable heat loss by roughly 30 % across the range — at a 150 °C surface under continuous operation, the allowable figure fell from about 104 W/m² to about 71 W/m². The petrochemical design code aligns with this. In practice, thicknesses that were compliant five years ago now need to be recalculated, and many do not pass. Surface temperature limits are explicit. For personnel protection the outer surface is normally held at 60 °C or below. For cold insulation the outer surface is held at or above ambient dew point plus 1–3 °C. Structure has its own rules. Insulation above 80 mm is built in layers, and where two different materials are layered, the interface temperature between them has to sit within about 0.9 of the outer layer's service limit — otherwise the inner layer cooks the outer one. A hot system is insulation plus weather jacket; a cold system is insulation plus vapour retarder plus jacket, and the retarder is not optional. On austenitic stainless surfaces, ion limits apply to everything in contact with the steel. Jacket design life should match or exceed the insulation service life, because a jacket that fails early destroys the system behind it. CUI has its own qualification standard. Insulation systems for service in the CUI temperature band — roughly -200 °C to 204 °C — are qualified against a dedicated international standard for corrosion under insulation, and coating systems are qualified by test rather than by description. Asking for that test report is the single most useful question in a petrochemical insulation enquiry. For glossary terms used across these material families, see our insulation glossary. Specification Checklist for a Petrochemical Enquiry Eight items will get you a firm answer rather than a range: - Continuous and peak operating temperature, per line or per zone. Not "high temperature" — the number. - Process fluid and any corrosion mechanism. Sulphidic, naphthenic acid, chlorides, amine — each changes the material and the coating. - Substrate metallurgy. Austenitic stainless triggers ion limits on everything touching it. - Geometry and clearance. Pipe diameter, vessel outside diameter, and the millimetres actually available. - Mechanical duty. Protected inside a casing, or clamped, walked on, vibrating or repeatedly stripped? - Water exposure. Outdoor, buried, washdown, or deluge system. This decides vapour retarder and jacketing. - Applicable standard and heat-loss limit. The design code and the revision year, because the limits moved recently. - Form and annual volume. Board, blanket, pre-formed pipe section, cut shape or coating, plus quantity. Ask for the conductivity curve across your operating range rather than a single value at ambient, and ask for lot-level test certificates rather than typical values. Petrochemical insulation is specified against service conditions, not datasheet headlines — on refinery duty the difference between grades is not visible on a datasheet. Closing Petrochemical insulation is four specifications, not one. Distillation needs two corrosion strategies on the same column. Cracking needs thermal shock resistance at 1 300 °C and layered construction at 11 MPa. Storage needs cryogenic dimensional stability at one end and fire performance at the other. Traced lines need flexibility and water resistance, and they are where most of the site's insulation volume and most of its CUI risk actually sit. Across all four, non-combustible inorganic material is the default, water management decides service life more often than conductivity does, and the recent tightening of allowable heat loss means most existing thickness schedules need recalculating. Send us the unit, the operating temperature, the substrate metallurgy, the clearance and the applicable standard, and our engineers will return a thickness calculation, a material schedule and a quotation within two weeks. Two follow-ups round out this petrochemical insulation guide. For a comparison of the two fibre families that carry most refinery hot duty, see our glass wool versus rock wool comparison. For the rigid board family used on load-bearing hot equipment, see our calcium silicate insulation guide. Explore our petrochemical plant insulation applications for reformers, crackers, and pipe racks in refining and petrochemicals. FAQ: Q: What insulation is used in a petrochemical plant? A: Rock wool and ceramic fibre carry the majority of hot duty. Rock wool covers hot pipework, columns and vessels up to about 650 °C; ceramic fibre serves cracking furnaces and reformers at 1 000–1 400 °C. Calcium silicate is used where the insulation has to carry load, glass wool on low-temperature and acoustic duty, foam glass and polyisocyanurate on cryogenic storage, and aerogel composite where clearance is constricted. Q: Why is A-grade non-combustible material required? A: Hydrocarbon service means any insulation on hot lines or vessels is a fire load if it burns. A1 or A-grade non-combustible material does not contribute to flame spread, which is why it is the default across high-temperature and flammable-media applications. Combustible organic foam is used only on cold service, where its low conductivity justifies the fire-engineering cost. Q: What is corrosion under insulation and how do you prevent it? A: CUI is corrosion of the steel surface beneath insulation, driven by water that enters the system and is held against warm metal. It is invisible until the insulation is stripped, which is why it is a leading cause of unplanned petrochemical maintenance. Prevention is water management — vapour retarders on cold systems, correct jacketing and sealing on hot ones — plus coating systems qualified by test rather than by description, and ion limits on austenitic stainless surfaces. Q: How thick should petrochemical pipe insulation be? A: It is calculated, not tabulated. Economic thickness method is usual for hot service, surface temperature method for personnel protection and condensation control, and heat balance method where freezing delay or a defined temperature drop rate governs. Typical results are 30–100 mm on low-temperature circuits and 50–150 mm on hot ones, and anything above 80 mm is built in layers. Q: What temperature does a cracking furnace insulation need to handle? A: Radiant sections operate at 600–1 300 °C and decoking pushes tube metal to about 1 400 °C. Ceramic fibre is the standard answer at 1 000–1 400 °C, with alumina fibre for 1 600–2 000 °C positions. Thermal shock resistance matters as much as the temperature rating, because the cracking and decoking cycle swings tube temperature by 50–80 °C per hour on shutdown. Q: Can rock wool be used on petrochemical pipework? A: Yes — it is the most widely used material for refinery hot pipework. Rock wool covers -200 to 650 °C, is A1 non-combustible, and is supplied as pre-formed pipe sections as well as blanket and board. Above roughly 650 °C ceramic fibre or calcium silicate takes over, and the choice between them depends on whether the duty is thermal or mechanical. Q: What is different about LNG tank insulation? A: Cryogenic service is governed by dimensional stability rather than conductivity alone. At about -165 °C the insulation must not shrink more than roughly 0.5 % and must retain bond strength above about 0.05 MPa, or it will crack away from the shell. Boil-off rate is the performance measure, and cold insulation is typically 150–200 mm thick with the outer surface held at or above ambient dew point plus 1–3 °C. Q: Do insulation thickness requirements change with the new standard? A: Yes, materially. The 2024 revision of the general equipment and pipe insulation standard cut allowable heat loss by roughly 30 % across the range — at a 150 °C continuous-duty surface the limit fell from about 104 W/m² to about 71 W/m². Thickness schedules calculated against the previous edition should be recalculated, and many will not pass without additional thickness or a lower-conductivity material. Q: What should I ask a supplier for in a petrochemical quotation? A: The conductivity curve across your operating range rather than a single ambient value, lot-level test certificates rather than typical values, the standard and revision year the design is calculated against, the coating and vapour retarder system with its qualification test report, and confirmation of ion limits if the substrate is austenitic stainless. Q: How often should petrochemical insulation be inspected? A: Inspection intervals are set by the CUI risk ranking of each circuit rather than by a single site-wide rule. Circuits that cycle through the CUI temperature band, run wet, or have a history of jacket damage are inspected most frequently. The practical point is that insulation is not fit-and-forget: jacket condition and seal integrity are what determine whether the system reaches its design life. ### Nano vs Aerogel vs Microporous: Choosing the Right Ultra-Thin Insulation URL: https://www.rosetexwool.net/news/nano-vs-aerogel-vs-microporous-ultra-thin-comparison/ 2026-09-08 | Author: Rosetexwool Editorial | Category: industry insight Summary: Aerogel leads at room temperature at 0.013–0.021 W/(m·K), microporous board wins above 600 °C at 0.030–0.038. Where each one pays back — and where each one fails. Specifying ultra-thin insulation usually starts the same way: the thermal calculation says you need 100 mm, the drawing says you have 35 mm, and someone asks which of the three high-performance families will close the gap. The honest answer is that all three can, and they fail in completely different places. This comparison is written for that moment. It puts nano insulation, aerogel and microporous board side by side on the five axes that actually decide a specification — thermal conductivity, temperature capability, density and strength, cost and service life, and the application each one is genuinely built for — then turns the result into a selection table you can take to a supplier. For the full material landscape beyond these three families, see our top 10 high-temperature insulation materials guide. What "Ultra-Thin" Actually Buys You Conventional mineral wool sits at 0.035–0.047 W/(m·K) and ceramic fibre at 0.038–0.060 W/(m·K) in service. All three high-performance families beat that by a wide margin, which is why they are described as ultra-thin: for the same heat loss and the same shell temperature, a lower conductivity translates directly into less thickness. The rule of thumb used across the industry is that roughly 10 mm of a high-performance material replaces about 50 mm of conventional insulation. That five-to-one ratio is what unlocks retrofits that were previously impossible — a pipe run that could never take 100 mm of mineral wool can usually take 20 mm of something better. The catch is that the ratio only holds while the material stays inside its design envelope. Push aerogel past its temperature ceiling and the ratio collapses. Put a vacuum panel somewhere it gets punctured and it collapses faster. The rest of this guide is about finding the envelope for each family. The Three Families at a Glance Nano insulation is an umbrella term rather than a single product. It covers nanofibre materials — SiO₂ and ZrO₂ nanofibre membranes, aerogel-fibre textiles — mesoporous materials with pore sizes below 70 nm, and vacuum insulation panels (VIP), which are the extreme case at 0.002–0.004 W/(m·K). Pore structure in the nanoporous grades runs 20–50 nm, which is why some suppliers classify them as a microporous sub-type. Aerogel is a nanostructured solid network with porosity of 80–99.8 % and pore sizes of 20–50 nm. It is supplied as silica aerogel for long-term duty at 400–600 °C, alumina aerogel for 600–800 °C, and as fibre-reinforced blanket or board composites that make the material handleable. Aerogel has the lowest thermal conductivity of any commercial solid, and at room temperature it is below still air. Microporous insulation is a pressed inorganic powder composite — fumed silica in most commercial grades — with pore sizes typically 7–12 nm or 30–60 nm depending on the grade, loaded with an infrared opacifier and sealed inside a barrier envelope. It does not need vacuum encapsulation to reach its numbers, and it is the strongest of the three in compression. For a deep dive on this family, see our nano microporous insulation guide. The single most important structural difference: aerogel and nanofibre products are flexible or semi-flexible, while microporous board is rigid. That one property decides more specifications than any conductivity number. Thermal Conductivity at 25 °C and at 800 °C Two temperatures tell the whole story, because the ranking reverses between them. Property | Nano | Aerogel | Microporous | Thermal conductivity at 25 °C | 0.018–0.025 W/(m·K) | 0.013–0.021 W/(m·K) | 0.018–0.021 W/(m·K) | Thermal conductivity at 800 °C | 0.035–0.052 W/(m·K) | 0.080–0.090 W/(m·K) | 0.030–0.038 W/(m·K) | VIP sub-class conductivity | 0.002–0.004 W/(m·K) | — | — | At room temperature, aerogel wins. At 0.013–0.021 W/(m·K) it is the lowest of the three and, remarkably, below the 0.025 W/(m·K) of still air. Nano and microporous sit close together at 0.018–0.025 and 0.018–0.021 respectively. If your duty is ambient to roughly 200 °C, aerogel is the correct default. At 800 °C, the order inverts completely. Microporous board holds 0.030–0.038 W/(m·K) — roughly a third to a quarter of aerogel's 0.080–0.090. The reason is structural: the aerogel skeleton loses stability above about 600 °C, the nanostructure begins to collapse, and conductivity climbs steeply. Microporous board has no such transition because it is a pressed powder with an opacifier rather than a delicate network. This is the single most common specification error in the category. A buyer compares datasheets at 25 °C, picks aerogel on the strength of that number, and installs it at 700 °C where microporous board would have given two to four times the insulating effect per millimetre. Temperature Limits and Long-Term Stability Short-term peak capability and long-term service temperature are different numbers, and conflating them is the second most common error. | Nano | Aerogel | Microporous | Short-term peak | 1 300 °C (nanofibre) | 1 200–1 400 °C (composite) | 1 200–1 400 °C | Long-term service | ≤ 800 °C (VIP), 800–1 000 °C (nanofibre) | 400–600 °C (silica), 600–800 °C (alumina) | 1 000–1 200 °C | Structural note | Vacuum degrades over time | Skeleton collapses above ~600 °C | Stable, no transition | Microporous board has the highest long-term service temperature of the three at 1 000–1 200 °C, and it is the reason the material dominates steel and petrochemical duty. Silica aerogel is a 400–600 °C material in continuous service; the 1 200–1 400 °C figures quoted for aerogel apply to short-term peaks and to alumina-composite grades, not to continuous duty on a silica blanket. VIP sits apart. Its conductivity is extraordinary, but performance depends on maintaining vacuum, and vacuum decays. A VIP is the right answer where you need maximum insulation in minimum thickness at low temperature and can guarantee the panel is never cut, punctured or crushed — cold-chain containers and controlled-temperature enclosures, not plant pipework. For how these limits map onto the conventional fibre and wool families, see our high-temperature insulation wool temperature ratings guide. Density, Strength and Handling on Site Property | Nano | Aerogel | Microporous | Density | 7.1–320 kg/m³ (VIP ≈ 450 kg/m³) | 3–250 kg/m³ | 200–320 kg/m³ | Compressive strength | 0.14–0.25 MPa (VIP ≤ 0.5 MPa) | 0.3–8 MPa (composite) | 3.5–5 MPa | Puncture resistance | > 100 N | 100–500 N (composite) | 100–150 N | Fabrication on site | Limited — VIP cannot be cut | High — cuts and wraps | High — cuts and re-seals | Service life | 10–15 years (VIP) | 15–20 years | 10–15 years | Aerogel is the lightest of the three at 3–250 kg/m³, which matters where structural load is the constraint. But raw aerogel is brittle and is essentially always used as a composite with a reinforcing fibre or scrim; the quoted 0.3–8 MPa compressive range applies to those composites, and mechanical performance falls as the temperature grade rises. Microporous board is the heaviest at 200–320 kg/m³ and by far the strongest at 3.5–5 MPa. That strength is what makes it usable as a load-bearing backup layer, on vibrating equipment, and in positions where the insulation is clamped or bolted rather than protected inside a casing. The fabrication line matters more than buyers expect. VIP cannot be cut on site at all — a cut edge is a failed panel, so every dimension has to be ordered. Aerogel cuts and wraps easily, which is why it suits complex geometry. Microporous board cuts with standard tools, but every cut face is an unsealed face and has to be re-sealed with foil tape before installation. Cost, Service Life and Lifecycle Value On first cost per square metre the ranking is stable across most markets: aerogel carries the highest material cost, driven largely by supercritical drying and the capital equipment behind it; microporous board sits in the middle and typically runs about 15 % below fibre-reinforced aerogel composites at comparable performance; VIP is the outlier, generally an order of magnitude above conventional insulation and used only where nothing else fits. First cost is the wrong comparison, and every experienced buyer in this category knows it. The right one is cost per unit of thermal resistance over the planned service life, which brings three other factors in: - Thickness reduction. Less insulation means less support steel, less cladding, smaller clearances and faster installation. - Service life. Aerogel quotes 15–20 years, nano and microporous 10–15 years, against three to five for conventional insulation. - Energy. For retrofit work, the reduction in heat loss usually shows up as a double-digit percentage saving on the insulated system, and payback on the premium material is often measured in a small number of years rather than decades. Aerogel is the rational choice where space is genuinely the binding constraint and the duty is moderate — the premium buys millimetres nothing else can. Microporous board wins the lifecycle argument on continuous high-temperature industrial duty, where the combination of 2–4 times the insulating effect per millimetre and a long stable service life outweighs a lower first cost that delivers less insulation. VIP only wins where its unique conductivity is the only way to meet the specification at all. For a worked comparison of how thickness assumptions move the economics against conventional materials, see our aerogel versus traditional insulation thickness and cost analysis. Where Each Material Wins: Four Real Scenarios Steel — ladles, converters and heat treatment. Furnace interiors run at 1 000–1 200 °C, the shell has to stay far below that, and the insulation has to survive mechanical abuse. Microporous board dominates here: it holds 1 000–1 200 °C continuously, carries 3.5–5 MPa in compression, and does not lose geometry at temperature. Measured results on ladle duty show molten steel temperature drop falling from more than 2 °C per minute to about 1 °C per minute, with shell temperature down 70–90 °C. Process pipework and steam lines at 300–400 °C. Aerogel is usually the answer. On a 350 °C steam line, aerogel has cut required insulation thickness by roughly two thirds against conventional material, and because it is flexible it wraps valves, flanges and irregular geometry without pre-formed shapes. The duty is comfortably inside aerogel's long-term range, so the room-temperature advantage holds. Battery packs and thermal runaway barriers. Aerogel is the default, normally encapsulated in a polymer film so that the material cannot shed dust into the pack. Its flexibility, thin section and low-temperature performance suit the application. Microporous board withstands 1 200 °C flame impingement better than aerogel does, but its thickness and rigidity limit it in pack design, so it appears only where the barrier is a separate structural element. Aerospace and defence. Both appear. Alumina-composite aerogel is used for thermal shielding and engine bay insulation where weight is critical, while rigid microporous board is supplied into certified aerospace positions under quality systems such as AS 9100. The deciding factor is usually whether the part needs to be light and shaped (aerogel) or rigid and load-bearing (microporous). For applications at the boundary between these families, our pyrogel versus mineral wool comparison walks through a worked cost-and-lifecycle case. Selection Cheat Sheet and Sourcing Checklist Start with temperature, then space, then mechanics: If your binding constraint is | Choose | Because | Space, at duty below 400 °C | Aerogel | Lowest conductivity at 0.013–0.021 W/(m·K) | Continuous duty above 600 °C | Microporous | 0.030–0.038 W/(m·K) at 800 °C, stable to 1 200 °C | The insulation must carry load | Microporous | 3.5–5 MPa compressive, rigid board | Weight is critical | Aerogel | 3–250 kg/m³, lightest of the three | Complex geometry, valves, flanges | Aerogel | Cuts and wraps on site | Vibration or frequent replacement | Aerogel or nanofibre | Flexible, mechanically durable | Absolute minimum thickness, low temperature | VIP (nano) | 0.002–0.004 W/(m·K), but never cut it | Maximum lifecycle value in static high-temperature plant | Microporous | Stable, strong, long-lived | Five things to put in the enquiry: - Operating temperature, continuous and peak. Not "high temperature" — the actual numbers. This single input eliminates two of the three families most of the time. - Geometry and available clearance. Pipe diameter or vessel outside diameter, plus the millimetres you actually have. - Mechanical duty. Is the insulation protected inside a casing, or is it clamped, bolted, walked on or vibrating? - Substrate and environment. Austenitic stainless steel means a chloride limit of 50 mg/kg or below. Water exposure means a hydrophobic grade or a waterproof jacket. - Volume and form. Board, blanket, pre-formed pipe section or cut shape, and annual quantity. Custom forms are routine but they move both lead time and minimum order quantity. Ask for the conductivity curve across your operating range, not a single value at 25 °C, and ask for lot-level test certificates rather than typical values. The gap between grades in this category is not visible on a datasheet. Closing Aerogel wins on conductivity at room temperature and on flexibility. Microporous board wins above 600 °C, in compression, and on lifecycle cost in continuous industrial service. Nano covers everything from nanofibre mats to vacuum panels, and the VIP sub-class is unmatched at low temperature and unusable the moment it is cut. If you take one thing from this comparison: specify against your operating temperature, not against the headline conductivity figure. The ranking genuinely reverses between 25 °C and 800 °C, and that reversal is where most of the wasted spend in this category happens. Send us your operating temperature, geometry, available clearance and annual volume, and our engineers will return a thickness calculation, a sample plan and a quotation within two weeks. For terminology used across these product families, see our insulation glossary. Frequently asked Which is better, aerogel or microporous insulation? It depends entirely on temperature. At 25 °C aerogel is best at 0.013–0.021 W/(m·K), below still air. At 800 °C microporous board is best at 0.030–0.038 W/(m·K) against aerogel's 0.080–0.090, because the aerogel skeleton loses stability above roughly 600 °C. Below 400 °C choose aerogel; above 600 °C choose microporous. What is the difference between nano and microporous insulation? "Nano insulation" is an umbrella term covering nanofibre materials, mesoporous materials and vacuum insulation panels, while microporous insulation is a specific pressed inorganic powder composite with an infrared opacifier. Some nanoporous grades have pore sizes of 20–50 nm and are marketed as a microporous sub-type, which is why the two names overlap in supplier literature. How much thinner is ultra-thin insulation than mineral wool? As a working rule, about 10 mm of a high-performance material replaces roughly 50 mm of conventional insulation for the same heat loss. The ratio only holds inside the material's design envelope — aerogel above 600 °C and VIP once punctured both lose the advantage quickly. Can aerogel be used at 800 °C? Not in continuous service. Silica aerogel is rated for long-term duty at 400–600 °C, and alumina grades reach 600–800 °C. The 1 200–1 400 °C figures quoted for composite aerogels are short-term peak values. For continuous duty at 800 °C, microporous board at 1 000–1 200 °C is the correct specification. Is microporous board stronger than aerogel? Yes, substantially. Microporous board reaches 3.5–5 MPa in compression against 0.3–8 MPa for composite aerogel, and it is rigid rather than flexible. That is why microporous board is used where the insulation is clamped, bolted or acting as a load-bearing backup layer, and why aerogel is used where flexibility and conformability matter more. Is vacuum insulation panel worth the cost? Only where its 0.002–0.004 W/(m·K) conductivity is the only way to meet the specification, and where the panel will never be cut, punctured or crushed. VIP typically costs an order of magnitude more than conventional insulation, cannot be cut on site, and its performance depends on vacuum that decays over time. Which material lasts longest in service? Aerogel quotes the longest at 15–20 years, with nano and microporous at 10–15 years. All three substantially exceed the three to five years typical of conventional insulation. The failure modes that shorten service are different: envelope damage and water ingress for microporous, skeleton collapse above temperature for aerogel, and vacuum loss for VIP. What should I send to get an accurate quotation? Continuous and peak operating temperature, the geometry — pipe diameter or vessel outside diameter — the clearance available, whether the insulation is protected or load-bearing, the substrate including whether it is stainless steel, any water exposure, the required form, and annual volume. With those items a producer can return a thickness calculation and a firm price rather than a range. Related products: Nano Aerogel Insulation Blanket Related applications: Building FAQ: Q: Which is better, aerogel or microporous insulation? A: It depends entirely on temperature. At 25 °C aerogel is best at 0.013–0.021 W/(m·K), below still air. At 800 °C microporous board is best at 0.030–0.038 W/(m·K) against aerogel's 0.080–0.090, because the aerogel skeleton loses stability above roughly 600 °C. Below 400 °C choose aerogel; above 600 °C choose microporous. Q: What is the difference between nano and microporous insulation? A: "Nano insulation" is an umbrella term covering nanofibre materials, mesoporous materials and vacuum insulation panels, while microporous insulation is a specific pressed inorganic powder composite with an infrared opacifier. Some nanoporous grades have pore sizes of 20–50 nm and are marketed as a microporous sub-type, which is why the two names overlap in supplier literature. Q: How much thinner is ultra-thin insulation than mineral wool? A: As a working rule, about 10 mm of a high-performance material replaces roughly 50 mm of conventional insulation for the same heat loss. The ratio only holds inside the material's design envelope — aerogel above 600 °C and VIP once punctured both lose the advantage quickly. Q: Can aerogel be used at 800 °C? A: Not in continuous service. Silica aerogel is rated for long-term duty at 400–600 °C, and alumina grades reach 600–800 °C. The 1 200–1 400 °C figures quoted for composite aerogels are short-term peak values. For continuous duty at 800 °C, microporous board at 1 000–1 200 °C is the correct specification. Q: Is microporous board stronger than aerogel? A: Yes, substantially. Microporous board reaches 3.5–5 MPa in compression against 0.3–8 MPa for composite aerogel, and it is rigid rather than flexible. That is why microporous board is used where the insulation is clamped, bolted or acting as a load-bearing backup layer, and why aerogel is used where flexibility and conformability matter more. Q: Is vacuum insulation panel worth the cost? A: Only where its 0.002–0.004 W/(m·K) conductivity is the only way to meet the specification, and where the panel will never be cut, punctured or crushed. VIP typically costs an order of magnitude more than conventional insulation, cannot be cut on site, and its performance depends on vacuum that decays over time. Q: Which material lasts longest in service? A: Aerogel quotes the longest at 15–20 years, with nano and microporous at 10–15 years. All three substantially exceed the three to five years typical of conventional insulation. The failure modes that shorten service are different: envelope damage and water ingress for microporous, skeleton collapse above temperature for aerogel, and vacuum loss for VIP. Q: What should I send to get an accurate quotation? A: Continuous and peak operating temperature, the geometry — pipe diameter or vessel outside diameter — the clearance available, whether the insulation is protected or load-bearing, the substrate including whether it is stainless steel, any water exposure, the required form, and annual volume. With those items a producer can return a thickness calculation and a firm price rather than a range. ### Nano & Microporous Insulation: Ultra-Thin High-Performance for Industrial Service URL: https://www.rosetexwool.net/news/nano-microporous-insulation-ultra-thin-high-performance/ 2026-09-08 | Author: Rosetexwool Editorial | Category: industry insight Summary: Nano microporous board delivers 0.016–0.030 W/(m·K) at up to 650 °C, cutting insulation thickness 50–70 %: how the pore structure works, ISO 18959:2025 classes, and the seven checks before you buy. Every industrial plant has the same three insulation problems: not enough space, too much heat escaping, and a surface someone can burn a hand on. Nano microporous board is the material that attacks all three at once — it reaches thermal conductivity of 0.016–0.030 W/(m·K) in service up to 650 °C, which is roughly a third of what a conventional mineral wool or ceramic fibre board needs to do the same job. In practice that means insulation thickness drops by 50–70 %, shell temperature falls by 30–40 %, and equipment that could never be insulated properly suddenly can be. This guide covers what nano microporous insulation actually is, the three physical mechanisms that make it work, the temperature classes defined by ISO 18959:2025, the physical and mechanical numbers you should see on a datasheet, where it fits across steel, petrochemical and power applications, how thin you can realistically go, and the seven checks to run before you sign a purchase order. It is written for procurement teams and plant engineers specifying ultra-thin high-temperature insulation for the first time. For the wider material landscape — where nano microporous board sits against aerogel, calcium silicate and ceramic fibre — see our top 10 high-temperature insulation materials guide. What Nano and Microporous Insulation Actually Is The naming is genuinely confusing, so start here. The same family of products is sold as nano microporous board, nanoporous insulation, nano-porous silica board, fumed silica board and microporous thermal insulation. They are all the same basic construction: an inorganic powder blend — fumed silica in most commercial grades — reinforced with a small fraction of fibre and loaded with an infrared opacifier, pressed into a rigid board or a preformed pipe section and sealed inside a high-barrier film or foil envelope. The sealing matters more than buyers expect. The performance comes from the pore structure, not from a vacuum in the everyday sense, but the envelope protects the board from moisture and mechanical damage during handling. A board that arrives with a punctured envelope has already lost part of its service life — which is why the foil-wrapped panel is the standard delivery form, and why damage in transit is a rejection reason rather than a cosmetic issue. It is worth separating this from aerogel, because the two get compared constantly. Aerogel insulation is a monolithic or blanket-form nanostructured network; nano microporous board is a pressed powder composite with an opacifier. Aerogel generally wins on very low conductivity at lower temperatures and on flexibility; the pressed microporous board wins on compressive strength, dimensional stability and rigidity at temperature. If your specification calls for a board that can be clamped, bolted or used as a load-bearing backup layer, the microporous board is usually the right answer. For a thickness-versus-cost comparison against aerogel and conventional materials, see our aerogel versus traditional insulation thickness and cost analysis. If you are still choosing between the three ultra-thin families rather than specifying one of them, our aerogel, nano and microporous insulation compared side by side guide puts all three on the same five axes. Three Mechanisms That Block Heat Transfer Heat moves through insulation by three routes — gas conduction and convection in the pores, solid conduction through the skeleton, and radiation across the pore space at temperature. Nano microporous board attacks all three. Pore size below the mean free path of air. The pores in a commercial board are typically 20–50 nm across. The mean free path of an air molecule at atmospheric pressure is about 70 nm. When the pore is smaller than the distance a molecule can travel before it collides with another molecule, gas-phase conduction collapses — the molecule meets a wall before it can pass energy along. This is the single biggest reason the material outperforms conventional insulation by a factor of three to four at 600 °C. A long, thin solid path. The skeleton is a packed powder with point contacts between particles. Solid conduction has to travel a tortuous route through countless contact points, each one a thermal resistance. The result is a solid-phase contribution far lower than in a fibre mat, where fibres form continuous conduction paths. Infrared opacification. At 600 °C and above, radiation becomes a serious share of total heat transfer through any low-density insulation. The opacifier — silicon carbide in most grades, sometimes a titanate — scatters and absorbs infrared across the wavelengths that matter. This is why the board's conductivity curve stays flat as temperature rises, while conventional materials climb steeply once radiation takes over. Put together, these mechanisms give a measured thermal conductivity 30–40 % below conventional insulation at 600 °C and around 40–50 % below at 400 °C. In the field that translates to thickness reductions of 50–70 % for the same shell temperature, and energy savings typically quoted in the 10–30 % range for retrofit work. ISO 18959:2025 and the Three Temperature Classes Until recently there was no dedicated international specification for this product family. ISO 18959:2025, published in September 2025 by ISO/TC 163/SC 3, changed that. It specifies requirements for factory-made rigid nano-microporous insulation used on industrial surfaces from 100 °C to 1 150 °C, delivered as board or pipe section, and it defines test procedures, conformity evaluation, marking and labelling. The standard sorts products into three classes by service temperature: Class | Service temperature | Thermal conductivity at 500 °C | Permanent linear change | Compressive stress at 10 % deformation | Type 950 | up to 950 °C | ≤ 0.036 W/(m·K) | ≤ 3.0 % | ≥ 200–500 kPa | Type 1050 | up to 1 050 °C | ≤ 0.045 W/(m·K) | ≤ 3.0 % | ≥ 200–500 kPa | Type 1150 | up to 1 150 °C | ≤ 0.045 W/(m·K) | ≤ 3.0 % | ≥ 200–500 kPa | Two practical points follow. First, the temperature class in the standard is normally set 50–100 °C below the material's actual short-term capability, so a Type 950 board is comfortably specified for the 650 °C duty this guide focuses on — and it carries the tighter conductivity limit of the three. Second, ISO 18959:2025 deliberately does not state the performance level a product must reach for a given application; that level comes from your project specification or from a non-conflicting national standard. So the class tells you what the product is, and your own thermal calculation tells you how much of it you need. If you are weighing this against the fibre and wool families, our high-temperature insulation wool temperature ratings guide maps the temperature ladder across material types. Physical and Mechanical Properties The datasheet numbers that matter for specification work: Property | Nano microporous board | Conventional insulation | Thermal conductivity | 0.016–0.030 W/(m·K) | 0.055–0.085 W/(m·K) at 600 °C | Density | 200–320 kg/m³ | 100–200 kg/m³ | Compressive strength | ≥ 0.3 MPa | 0.05–0.2 MPa | Linear shrinkage, 800 °C × 24 h | ≤ 2.0 % | 3.0–5.0 % | Fire classification | A1 non-combustible | B1 in many grades | Service life | 5–10 years | 3–5 years | Shell temperature in service | 50–60 °C | 80–90 °C | Two of these deserve comment. The density is genuinely higher than conventional insulation — 200–320 kg/m³ against 100–200 kg/m³ — yet compressive strength is five to six times better at 0.3 MPa or above. That combination is what makes the board usable in vibrating equipment and in positions where it carries load, rather than sitting protected inside a casing. The shrinkage figure is the second one: at 2.0 % or less after 24 hours at 800 °C, the board holds its geometry where conventional materials close up joints and open gaps. Chemically the product is fully inorganic, A1 non-combustible, and available in low-chloride grades. That last point is not optional on stainless steel. Where It Fits: Steel, Petrochemical and Power Steel — heat treatment furnaces and ladles. Furnace interiors run at 1 000–1 200 °C, but the shell has to stay below 650 °C and there is rarely room for a thick lining. A 7 mm microporous board has replaced conventional ceramic fibre in ladle applications where the benefit was measured directly: molten steel temperature drop fell from more than 2 °C per minute to about 1 °C per minute, and shell temperature dropped by 70–90 °C. Installation practice matters as much as the material — stagger the joints to break the thermal bridge, keep gaps to 1 mm or less, seal joints with foil tape so powder cannot escape, and fix with stainless steel banding or rivets rather than adhesive. On stainless shells, specify a low-chloride grade at 50 mg/kg chloride or below to avoid stress-corrosion cracking. Petrochemical — hot pipework and vessels. Process lines typically run 300–600 °C, with some services reaching 650 °C, and the available clearance around a pipe is often fixed by the original design. At 650 °C the microporous solution needs roughly one third of the thickness of mineral wool for the same heat loss, which is frequently the difference between a line that fits and one that does not. The material is inorganic, A1 rated and chloride-free, so it suits corrosive environments. Seal every joint with a high-temperature sealant so condensate cannot wick into the insulation, and wrap with foil or glass cloth for mechanical protection. In wet service, use a hydrophobic grade or add a waterproof jacket — a non-hydrophobic board that takes water has lost most of its advantage. For a broader view of pipe insulation options by material, see our industrial pipe insulation materials hub. Power — boilers, piping and casings. Boiler surfaces and steam piping span 200–600 °C, and the driver here is usually safety and efficiency together. Retrofit work on high-pressure steam piping has taken surface temperature from about 85 °C down to roughly 45 °C while cutting insulation thickness by 60–70 %. The board resists vibration and does not powder at temperature, which is why it holds up on boiler casings where fibre products break down. Use a metal outer jacket — stainless where the environment demands it — and specify a hydrophobic grade or waterproof cladding in damp areas. Board, Pipe Section and How Thin You Can Go Commercial board is commonly supplied from about 7 mm upward, with 7–20 mm covering the majority of industrial retrofits. Pipe sections are produced to the pipe diameter, and shaped or cut pieces are available for valves, flanges and irregular geometry. The temptation is always to go as thin as the thermal calculation allows. Resist it slightly. Below a certain thickness you are trading two real risks for space: more joints per square metre, each one a thermal bridge and a potential powder leak, and less mechanical margin against vibration and handling damage. A 7 mm board on a ladle works because the surface is smooth, the fixing is mechanical and the run is short. The same thickness on a long vibrating pipe run with twenty joints is a different proposition. Two installation details decide whether the calculated performance is achieved on site. Stagger joints between layers and between adjacent boards, and hold the joint gap to 1 mm or less. Then seal every joint with foil tape. Powder migration through an unsealed joint is slow, invisible, and permanent — the board thins at the seam and a hot line appears directly over it. Sourcing: Seven Things to Verify Before You Sign - Match the temperature class to the duty, not to the marketing. For service up to 650 °C, Type 950 per ISO 18959:2025 is the right specification and carries the strictest conductivity limit of the three classes. - Ask for the conductivity curve, not a single number. A datasheet quoting only a value at 25 °C tells you nothing about service. You want the figure at your operating temperature — 0.030–0.040 W/(m·K) at 600 °C and 0.024–0.029 W/(m·K) at 400 °C are the ranges a credible board should meet. - Set the chloride limit in writing. 50 mg/kg or below for anything mounted on austenitic stainless steel, with the value on the lot certificate rather than in an email. - Confirm mechanical and dimensional numbers. Density 200–320 kg/m³, compressive strength at 0.3 MPa or above, linear shrinkage 2.0 % or below at 800 °C for 24 hours. - Inspect the envelope. Reject boards with punctured, creased or delaminated foil. Seal integrity is a performance property, not packaging. - Require lot-level testing and traceability. Density, conductivity at a stated reference temperature, compressive strength at 10 % deformation, water repellency where specified, and the chloride number. For critical service, independent third-party verification is worth the lead time. - Send a proper enquiry. State the operating temperature, the geometry — pipe diameter or vessel outside diameter — the available clearance, the environment, and annual volume. Custom shapes and non-standard thicknesses are routine but they move both lead time and minimum order quantity. On channel choice, direct-from-mill buying gives the best price and the strongest custom capability on large projects, while distributors and integrators trade some price for faster delivery and better technical support on smaller ones. Either way, ask for samples and put them in a test rig before committing volume — the difference between grades is not visible on a datasheet. For a worked example of how thickness assumptions change the economics, see our pyrogel insulation thickness guide. Closing Nano microporous insulation is not a universal replacement for mineral wool or ceramic fibre — it is a specialist tool for the jobs where space, shell temperature or service life is the binding constraint. Where it fits, it fits decisively: half to two thirds of the thickness, a third of the conductivity, and a shell temperature your maintenance team can work next to. Send us your operating temperature, geometry, clearance and annual volume, and our engineers will return a thickness calculation, a sample plan and a quotation within two weeks. For the full material comparison across high-temperature insulation families, see our top 10 high-temperature insulation materials guide. For definitions of the terminology used across these product families, see our insulation glossary. Frequently asked What is the difference between nano microporous board and aerogel insulation? Aerogel is a monolithic or blanket-form nanostructured network that generally achieves very low conductivity at lower temperatures and offers flexibility. Nano microporous board is a pressed inorganic powder composite with an infrared opacifier, sealed in a barrier film — it is rigid, considerably stronger in compression at 0.3 MPa or above, and dimensionally stable at temperature. Choose aerogel where you need a flexible thin layer; choose the pressed board where the insulation must be clamped, bolted or used as a rigid backup layer. How thin can nano microporous insulation be? Commercial board starts at about 7 mm and is routinely supplied in the 7–20 mm range for industrial retrofits; pipe sections are made to diameter. Going thinner than the thermal calculation requires is usually a mistake, because thinner board means more joints per square metre, and every joint is a thermal bridge plus a potential powder-leak path. What temperature classes does ISO 18959:2025 define? Three, by service temperature: Type 950 up to 950 °C with thermal conductivity at 500 °C of 0.036 W/(m·K) or less; Type 1050 up to 1 050 °C at 0.045 W/(m·K) or less; and Type 1150 up to 1 150 °C at 0.045 W/(m·K) or less. All three carry a permanent linear change limit of 3.0 % and a compressive stress at 10 % deformation of 200–500 kPa or above. The standard covers surfaces from 100 °C to 1 150 °C. Is nano microporous board non-combustible? Yes — the product is fully inorganic and classified A1 non-combustible, which is one grade above the B1 classification typical of many conventional organic-bonded insulation products. That classification is part of why it is specified on furnace shells, boiler casings and pipework where fire performance is written into the project specification. Does nano microporous board need protection from moisture? Standard grades do. The pore structure works because the pores are dry and gas-filled; water in the pores restores conduction paths and the advantage disappears. In damp or outdoor service, specify a hydrophobic grade, add a waterproof jacket, or both. Always seal joints with foil tape so condensate cannot wick into the board. What chloride limit applies for stainless steel service? 50 mg/kg or below, and it should appear on the lot certificate rather than only in correspondence. Chloride plus moisture plus tensile stress is the classic recipe for stress-corrosion cracking in austenitic stainless steel, and insulation is a well-documented source of the chloride. How long does nano microporous insulation last in service? Five to ten years is the normal expectation, against three to five years for conventional insulation — roughly two to three times the service life. The two failure modes that shorten it are envelope damage during handling or installation, and water ingress through unsealed joints. Can the board be cut on site? It can be cut with standard tools, but every cut edge is an unsealed edge. If you cut a board, seal the cut face with foil tape before installation. Where possible, order pre-cut shapes and pipe sections from the producer so the factory envelope stays intact. Is nano microporous board worth the price compared with ceramic fibre? On first cost, no — the board is more expensive per square metre. On installed cost, frequently yes: 3–4 times the insulation efficiency means 50–70 % less thickness, less support steel, faster installation and 2–3 times the service life. The comparison to run is cost per unit of thermal resistance over the planned service life, not cost per square metre. What should I send to get an accurate quotation? Operating temperature, the geometry — pipe diameter or vessel outside diameter — the clearance available for insulation, the environment including any water exposure, whether the substrate is stainless, and your annual volume. With those five items a producer can return a thickness calculation and a firm price rather than a range. Related products: Nano Insulation Board Related applications: Cryogenic Insulation FAQ: Q: What is the difference between nano microporous board and aerogel insulation? A: Aerogel is a monolithic or blanket-form nanostructured network that generally achieves very low conductivity at lower temperatures and offers flexibility. Nano microporous board is a pressed inorganic powder composite with an infrared opacifier, sealed in a barrier film — it is rigid, considerably stronger in compression at 0.3 MPa or above, and dimensionally stable at temperature. Choose aerogel where you need a flexible thin layer; choose the pressed board where the insulation must be clamped, bolted or used as a rigid backup layer. Q: How thin can nano microporous insulation be? A: Commercial board starts at about 7 mm and is routinely supplied in the 7–20 mm range for industrial retrofits; pipe sections are made to diameter. Going thinner than the thermal calculation requires is usually a mistake, because thinner board means more joints per square metre, and every joint is a thermal bridge plus a potential powder-leak path. Q: What temperature classes does ISO 18959:2025 define? A: Three, by service temperature: Type 950 up to 950 °C with thermal conductivity at 500 °C of 0.036 W/(m·K) or less; Type 1050 up to 1 050 °C at 0.045 W/(m·K) or less; and Type 1150 up to 1 150 °C at 0.045 W/(m·K) or less. All three carry a permanent linear change limit of 3.0 % and a compressive stress at 10 % deformation of 200–500 kPa or above. The standard covers surfaces from 100 °C to 1 150 °C. Q: Is nano microporous board non-combustible? A: Yes — the product is fully inorganic and classified A1 non-combustible, one grade above the B1 classification typical of many conventional organic-bonded insulation products. That classification is part of why it is specified on furnace shells, boiler casings and pipework where fire performance is written into the project specification. Q: Does nano microporous board need protection from moisture? A: Standard grades do. The pore structure works because the pores are dry and gas-filled; water in the pores restores conduction paths and the advantage disappears. In damp or outdoor service, specify a hydrophobic grade, add a waterproof jacket, or both. Always seal joints with foil tape so condensate cannot wick into the board. Q: What chloride limit applies for stainless steel service? A: 50 mg/kg or below, and it should appear on the lot certificate rather than only in correspondence. Chloride plus moisture plus tensile stress is the classic recipe for stress-corrosion cracking in austenitic stainless steel, and insulation is a well-documented source of the chloride. Q: How long does nano microporous insulation last in service? A: Five to ten years is the normal expectation, against three to five years for conventional insulation — roughly two to three times the service life. The two failure modes that shorten it are envelope damage during handling or installation, and water ingress through unsealed joints. Q: Can the board be cut on site? A: It can be cut with standard tools, but every cut edge is an unsealed edge. If you cut a board, seal the cut face with foil tape before installation. Where possible, order pre-cut shapes and pipe sections from the producer so the factory envelope stays intact. Q: Is nano microporous board worth the price compared with ceramic fibre? A: On first cost, no — the board is more expensive per square metre. On installed cost, frequently yes: 3–4 times the insulation efficiency means 50–70 % less thickness, less support steel, faster installation and 2–3 times the service life. The comparison to run is cost per unit of thermal resistance over the planned service life, not cost per square metre. Q: What should I send to get an accurate quotation? A: Operating temperature, the geometry — pipe diameter or vessel outside diameter — the clearance available for insulation, the environment including any water exposure, whether the substrate is stainless, and your annual volume. With those five items a producer can return a thickness calculation and a firm price rather than a range. ### Rock Wool Pipe Production: How Rock Wool Pipe Sections Are Made URL: https://www.rosetexwool.net/news/rock-wool-pipe-production-how-its-made/ 2026-09-07 | Author: Rosetexwool Editorial | Category: industry insight Summary: Rock wool pipe production flow: raw basalt, melt at 1500–1600 °C, centrifugal fiberization, three-dimensional forming, curing, and cutting — and what to verify when sourcing a producer. Every rock wool pipe section you order — for steam mains, petrochemical lines or HVAC risers — starts the same way: basalt, dolomite and a little recycled slag go into an electric furnace, melt into a 1500–1600 °C liquid, then leave as a thin stream that a four-roller centrifuge breaks into fibres. From there, binder, forming, curing and packaging decide whether the section you receive is a precision shell or a piece of felt in pipe shape. This guide walks through the production flow that actually determines pipe-section quality — raw material control, melt consistency, fibre geometry, binder chemistry, three-dimensional vs pendulum vs sedimentation forming, curing profile, and the testing that proves each lot. It is written for procurement teams that need to ask informed questions when sourcing a producer, and for plant engineers who want to know why one supplier's pipe section feels stiffer, cuts cleaner or holds its shape longer than another. For the spec-level selection side — density class, binder grade, two-temperature window, A1 non-combustible and what to install on site — see our rock wool pipe insulation specs and selection guide. Raw Materials: Basalt, Slag, and the Acidity Coefficient The first thing that determines a rock wool pipe section's quality is what goes into the furnace. The standard recipe mix is basalt at 60–70 %, with dolomite and a little recycled slag making up the balance; the acidity coefficient — silica + alumina divided by lime + magnesia — is held at or above 1.6 to keep the fibre chemically stable at temperature. Sub-acid blends slump above 650 °C and are easy to spot in a hot-face failure. Raw material preparation is mostly grinding, screening and weighing: ore is crushed to a particle size below 5 mm so the furnace melts it evenly; moisture is held below 0.5 % to avoid steam explosions at the melt surface; and a V-type blender ensures the recipe mix stays consistent from batch to batch. Variations in the recipe show up weeks later, when sections begin to crack or slump on hot pipes — never blame the binder first; check the chemistry. For the deeper raw-material story, including recycled-stream handling and trace-element control, see our rock wool raw materials and manufacturing process guide. High-Temperature Melt: Electric Furnaces Win A modern rock wool pipe line uses an electric furnace, not a cupola. The reason is control. An electric furnace holds melt temperature within ±1 °C using PID feedback; a cupola drifts within ±5 °C. Both work, yet the electric furnace keeps melt viscosity stable, which keeps fibre diameter stable — and stable fibre diameter is the single biggest predictor of a consistent section. The melt zone runs at 1500–1600 °C, with melt time around 30–60 minutes and melt fluidity (a standardised flow test) targeted at 0.8–1.2 seconds. A good line has a chlorine-ion control on the feed so finished fibres stay below 10 mg/kg of chloride — important if the section will be mounted on austenitic stainless pipework, where moisture plus chloride is a stress-corrosion-cracking recipe. When you visit a producer, the melt area is the first place to look. A clean furnace with continuous temperature logging and a fixed schedule is a different operation from a leaky cupola with manual gates — even if the fibre section that comes out looks identical. Centrifugal Fibre Formation: Spinning the Wool The melt flows through a stream nozzle into a four-roller centrifuge. Primary rollers spin at roughly 2500–3000 rpm; the final roller runs at 7000–8000 rpm. Combined, they pull the melt into filaments with a target diameter of 4–7 μm — fine enough to trap air for low thermal conductivity, coarse enough to be mechanically stable. A laser scanner on the production line measures fibre diameter online; a deviation beyond about ±0.5 μm is the first warning that the binder will not bond evenly through the section's depth. Fibre uniformity is what separates a good pipe section from a great one. A laser or X-ray uniformity check on the loose mat before forming gives a single-point density tolerance inside ±5 % — that tolerance carries through to the finished section's thermal performance. If a producer cannot tell you their fibre diameter and uniformity numbers on the production line, they are not measuring them. Resin binder is sprayed onto the fibre stream at 3–5 % of finished weight; for hydrophobic grades, a silicone water-repellent is added at 0.5–1 %. Slag ball content — the un-fibrised droplets — is held below 12 % above 0.25 mm particle size by a vibrating screen at the bottom of the fibre collector. Slag balls reduce thermal conductivity and increase weight without contributing to insulation value. Forming: Sedimentation, Pendulum, and Three-Dimensional Once the fibre mat lands, the next choice decides whether the section will live on a steam line or only inside a wall cavity. Three methods are used commercially: Method | Fibre orientation | Density tolerance | Compressive strength | Slag content | Typical use | Sedimentation | Planar (horizontal layers) | ±10 % | ≤ 40 kPa | ≥ 10 % | Low-density pipe sections, light commercial | Pendulum | Partly vertical (woven layers) | ±5 % | ≥ 80 kPa | ≤ 10 % | Medium-density pipe sections, general industrial | Three-dimensional (3D) | Multi-axis, interlocked | ±3 % | ≥ 120 kPa | ≤ 7 % | High-density, high-temperature pipe sections | Three-dimensional forming rotates fibre layers by up to ±30° between passes, producing an interlocked structure that resists vibration and hot-face erosion. If you are buying rock wool pipe sections for high-temperature steam mains or for service lines above 250 °C, specify the three-dimensional process. If the producer cannot name the process they use, the answer is sedimentation — and the section will not perform as expected. For an inside look at how the centrifugal fibre stream flows into a glass wool line, see our centrifugal glass wool production guide. The mineral chemistry is different, but the principle of fibre formation and binder application is shared. Curing and Cutting: Where Tolerance Becomes Roundness Curing is a tunnel oven, typically 125–150 m long, with three zones: a preheat at 180 °C for 1–2 minutes, a main cure at 220–250 °C for 3–5 minutes, and a forced-air cool-down to below 60 °C. The phenolic resin binder cross-links in the main cure zone; the cooling rate is held at 5–10 °C/minute to keep the section from warping. Hot-face temperature inside the oven should be uniform within ±3 °C; otherwise, soft spots appear in the cured section that you only find when the section is cut open on site. After curing, the section is cut to size. Inner diameter is set by the mandrel; outer diameter by the cutting width. Tolerance targets: wall thickness ±2 mm, length tolerance ±3 mm, roundness error below 1.5 %. The longitudinal seam — where the mat meets itself along the length — is sealed by a high-frequency heated belt that briefly hits about 200 °C to fuse the binder, leaving a continuous, gap-free joint. A section that meets these tolerances will install cleanly and produce consistent shell temperature in service. A section that misses roundness will gap at installation, generate hot spots, and degrade faster at the seam — a defect you cannot see from the outside. Quality Testing: What the Lot Certificate Must Show A good producer sends a lot certificate with every delivery. The minimum checks, beyond the obvious dimensions, are: density (each batch, target ±5 %), thermal conductivity ( 25 °C reference, 0.035–0.045 W/(m·K) ), compressive strength at 10 % deformation, water repellency for hydrophobic grades ( 98 % or better ), and acidity coefficient ( 1.6 or higher ). For stainless-steel service, the chloride number — should be at or below 0.05 % — must be on the certificate. Traceability closes the loop. A real traceability system lets you take a serial number from a delivered section back to the raw-material batch, the furnace run, the binder lot, the forming line, and the curing oven profile. If the producer can show you that record, you have a real quality system. If they hand you only a datasheet, you have a marketing system. Environmental Compliance: What to Look For Modern rock wool pipe production is a regulated operation. A compliant producer carries an ISO 14001 environmental certification, holds a valid discharge permit, and reports against current emission limits. At the bag filter, particulate should be below 10 mg/m³; at the desulfurisation stack, SO₂ below 35 mg/m³; wastewater recycle rate at or above 90 %; solid waste — primarily cured-edge trim — reused at 100 %. Carbon intensity, increasingly reported in kgCO₂ per cubic metre of product, should be consistent with industry benchmarks and disclosed on request. If your project specifies green-building certification or low-carbon material credits, ask for the producer's carbon-intensity disclosure and their renewable-electricity share before you sign the order. How to Choose a Producer in One Page A short checklist for the sourcing team — keep it on the next supplier-qualification trip: - Process: three-dimensional forming for sections above 250 °C service; pendulum for general industrial; sedimentation only for low-density, low-temperature duty - Melt: electric furnace with continuous temperature logging; chloride control on the feed - Fibre: 4–7 μm diameter with laser scanning and a written tolerance - Tolerance: ±5 % single-point density; ±2 mm wall; ≤ 1.5 % roundness - Testing: ISO 9001 quality system, on-site thermal-conductivity testing, full lot certificate with every delivery - Traceability: serial number back to raw-material batch and furnace run - Environmental: ISO 14001, current discharge permit, reported emissions and carbon intensity - Capacity: at least one production line capable of 30,000 tonnes/year or more, so your volume is never more than 5 % of their annual capacity If the answer to all eight is yes, you are looking at a serious producer. If three or more are missing, the savings will not be worth the field failures. Closing A rock wool pipe section looks like a simple product. It is not. What you are buying is the cumulative discipline of raw material chemistry, melt control, fibre geometry, binder chemistry, forming method, curing profile and traceability — all executed lot after lot. The cheapest section is rarely the cheapest installed. Send us your pipe size, operating temperature, environment and annual volume, and our engineers will return a sampling plan and a quotation within two weeks. For the spec-level selection side of pipe insulation — what the datasheet must show, two binder grades, supplier-qualification questions and installation notes — see our rock wool pipe insulation specs and selection guide. For the broader pipe insulation market and how rock wool compares with aerogel and calcium silicate, see our industrial pipe insulation materials hub. Frequently asked What is the difference between sedimentation, pendulum and three-dimensional forming in rock wool pipe sections? Sedimentation lays fibres in horizontal layers with a single-point density tolerance of about ±10 % and compressive strength at or below 40 kPa. Pendulum rotates layers partly vertical, tightening tolerance to ±5 % and lifting compressive strength to 80 kPa or higher. Three-dimensional forming rotates layers by up to ±30° between passes, producing an interlocked structure with ±3 % density tolerance and ≥ 120 kPa compressive strength. For high-temperature service above 250 °C, three-dimensional forming is the right specification. What melt temperature is used in rock wool pipe production? Modern electric furnaces run at 1500–1600 °C, with continuous PID temperature control holding the melt inside ±1 °C. A cupola can also melt rock, but it drifts within ±5 °C — enough to shift fibre diameter and create density drift in finished sections. When you visit a producer, the melt area is the first place to inspect: clean furnace, continuous logging, fixed schedule. What binder content do rock wool pipe sections use? Phenolic resin binder at 3–5 % of finished weight is standard. For hydrophobic grades, a silicone water-repellent is added at 0.5–1 %. Higher binder content does not mean better quality: too much binder reduces the fibre-to-fibre air space and raises thermal conductivity; too little binder produces sections that shed fibres during cutting and installation. What fibre diameter should I expect in a high-quality rock wool pipe section? 4–7 μm is the standard range. A laser scanner on the production line measures diameter online; deviation beyond ±0.5 μm triggers an alarm and a process adjustment. Finer fibres trap more air and lower thermal conductivity; coarser fibres give better mechanical stability. The right answer for pipe sections is in the middle of this range. How do I check slag ball content in a rock wool pipe section? Ask the producer for the value. A vibrating screen on the fibre collector removes slag balls above 0.25 mm; good production keeps the slag ball content at 7 % or lower for three-dimensional sections, and at or below 12 % above 0.25 mm across all grades. Slag balls do not insulate — they are just weight — so a high slag ball number is a sign of an under-controlled melt. What is the typical curing temperature for rock wool pipe sections? The curing oven runs in three zones: 180 °C preheat, 220–250 °C main cure, and forced-air cool-down to below 60 °C. Total residence time is typically 5–7 minutes. Hot-face temperature inside the oven should be uniform within ±3 °C. Uneven cure produces soft spots in the finished section that show up only when the section is cut open. What lot certificate should come with every rock wool pipe section delivery? Dimensions and density (with single-point tolerance), thermal conductivity at a 25 °C reference, compressive strength at 10 % deformation, water repellency for hydrophobic grades, and acidity coefficient. For austenitic stainless service, the chloride number — at or below 0.05 % — must be on the certificate. A complete traceability record, linking the serial number back to the raw-material batch, furnace run, binder lot and oven profile, is the final item. What is a realistic lead time for custom-density rock wool pipe sections? A serious producer runs standard density grades on a continuous schedule, with 4–6 week lead time for stock diameters and densities. Custom density, non-standard diameter or shaped sections add 2–4 weeks for tooling and process adjustment, and carry a minimum order quantity — usually one full container or more. If your order is below that minimum, expect a longer lead time or a small-batch surcharge. What environmental certifications should a rock wool pipe producer carry? At minimum, ISO 14001 environmental management certification and a valid local discharge permit. For projects with green-building or low-carbon material credits, the producer should be able to disclose their carbon-intensity figure (kgCO₂ per cubic metre of product), renewable-electricity share, and emission-monitoring records. Wastewater recycle rate and 100 % solid-waste reuse are the easiest indicators to verify on a site visit. Related products: Rockwool Pipe Insulation for Steam Pipes Related applications: Cement, Building FAQ: Q: What is the difference between sedimentation, pendulum and three-dimensional forming in rock wool pipe sections? A: Sedimentation lays fibres in horizontal layers with a density tolerance around ±10 % and compressive strength at or below 40 kPa. Pendulum rotates layers partly vertical, tightening tolerance to ±5 % and lifting compressive strength to 80 kPa or higher. Three-dimensional forming rotates layers by up to ±30° between passes, producing an interlocked structure with ±3 % density tolerance and ≥ 120 kPa compressive strength. For high-temperature service above 250 °C, three-dimensional forming is the right specification. Q: What melt temperature is used in rock wool pipe production? A: Modern electric furnaces run at 1500–1600 °C, with continuous PID temperature control holding the melt inside ±1 °C. A cupola can also melt rock, but it drifts within ±5 °C — enough to shift fibre diameter and create density drift in finished sections. The melt area is the first place to inspect during a supplier visit. Q: What binder content do rock wool pipe sections use? A: Phenolic resin binder at 3–5 % of finished weight is standard. For hydrophobic grades, a silicone water-repellent is added at 0.5–1 %. Higher binder content does not mean better quality: too much binder reduces fibre-to-fibre air space and raises thermal conductivity; too little produces cutting-shed sections that lose fibres during installation. Q: What fibre diameter should I expect in a high-quality rock wool pipe section? A: 4–7 μm is the standard range. A laser scanner on the production line measures diameter online; deviation beyond ±0.5 μm triggers an alarm and a process adjustment. Finer fibres trap more air and lower thermal conductivity; coarser fibres give better mechanical stability. Pipe sections typically land in the middle of this range. Q: How do I check slag ball content in a rock wool pipe section? A: Ask the producer for the value. A vibrating screen on the fibre collector removes slag balls above 0.25 mm; good production keeps slag ball content at 7 % or lower for three-dimensional sections, and at or below 12 % above 0.25 mm across all grades. Slag balls do not insulate — they are just weight. Q: What is the typical curing temperature for rock wool pipe sections? A: The curing oven runs in three zones: 180 °C preheat, 220–250 °C main cure, and forced-air cool-down to below 60 °C. Total residence time is typically 5–7 minutes. Hot-face temperature inside the oven should be uniform within ±3 °C. Uneven cure produces soft spots in the finished section that only show up when the section is cut open. Q: What lot certificate should come with every rock wool pipe section delivery? A: Dimensions and density (with single-point tolerance), thermal conductivity at a 25 °C reference, compressive strength at 10 % deformation, water repellency for hydrophobic grades, and acidity coefficient. For austenitic stainless service, the chloride number — at or below 0.05 % — must be on the certificate. A complete traceability record, linking the serial number back to the raw-material batch, furnace run, binder lot and oven profile, is the final item. Q: What is a realistic lead time for custom-density rock wool pipe sections? A: A serious producer runs standard density grades on a continuous schedule with 4–6 week lead time for stock diameters and densities. Custom density, non-standard diameter or shaped sections add 2–4 weeks for tooling and process adjustment, and carry a minimum order quantity — usually one full container or more. Below that minimum, expect a longer lead time or a small-batch surcharge. Q: What environmental certifications should a rock wool pipe producer carry? A: At minimum, ISO 14001 environmental management certification and a valid local discharge permit. For projects with green-building or low-carbon material credits, the producer should be able to disclose their carbon-intensity figure (kgCO₂ per cubic metre of product), renewable-electricity share, and emission-monitoring records. Wastewater recycle rate and 100 % solid-waste reuse are the easiest indicators to verify on a site visit. Q: Can rock wool pipe sections be produced to a custom inner diameter and wall thickness? A: Yes, for inner diameters from about DN 50 to DN 300 and wall thickness from roughly 20 mm to 150 mm, on a custom run. Outside that envelope — larger diameters, very thin walls, or unusual shapes — lead time and minimum order quantity rise sharply. Confirm the envelope with the producer when requesting a quotation. ### Rock Wool Pipe Insulation: Specs, Production & Selection URL: https://www.rosetexwool.net/news/rock-wool-pipe-insulation-specs-production-selection/ 2026-09-07 | Author: Rosetexwool Editorial | Category: industry insight Summary: Rock wool pipe insulation: spec, production and supplier qualification for industrial pipework up to 750 °C, Class A1 non-combustible, with hydrophobic options for wet service. Rock wool pipe insulation is the pre-formed, half-rigid pipe section that lines industrial and HVAC piping when Class A1 fire rating, long-term temperature resistance to 750 °C, and a stable, predictable shell temperature matter more than the thinnest possible wall. Compared with multi-material composite systems (rock wool + aluminium + GRP), it is one single part to specify, one part to install, and one part to inspect. This guide walks through the spec, the five-step production line, how to qualify a supplier, and what to check on site. If you are scoping a project from the broader pipe-insulation material angle, see our industrial pipe insulation materials guide for the side-by-side of rock wool, calcium silicate, aerogel, PIR, and elastomeric options, and the industrial pipe insulation types comparison for the quick decision table. The product page for our own pre-formed rock wool pipe sections is the practical entry point for samples and quotation. Specification: What the Datasheet Should Show A datasheet you can trust contains the following items. Anything missing is a question to ask before signing the PO. Property | Typical range | Why it matters | Density | 80–200 kg/m³; 100–150 kg/m³ for general service | Higher density raises compressive strength and λ slightly; lower density is easier to wrap but more fragile in transit | Thermal conductivity | ≤0.035 W/(m·K) at 70 °C (ASTM C518) | Drives wall thickness and shell heat loss | Long-term service temperature | up to 750 °C (high-temperature binder grade); 650 °C (standard binder) | Above 250 °C you must specify the high-temperature grade, otherwise the binder breaks down | Short-term peak | 1000 °C for ≤30 min | Covers start-up, flame duct excursions, and E-stop events | Compressive strength | ≥10 kPa for general pipe, ≥15 kPa for high-pressure pipe | Prevents the insulation from going out-of-round on larger-diameter pipes | Tensile strength (perpendicular to faces) | ≤0.08 MPa | Holds the section together when the jacket is removed and re-fitted for inspection | Linear shrinkage after heat soak | ≤2 % at design temperature | Predicts whether the lining will open joints after a few years | Water absorption (hydrophobic grade) | ≤1 % by weight, water repellency ≥98 % | Required for outdoor, marine, and underground wet service | Chloride content | ≤0.05 % | Below this, rock wool will not stress-crack stainless-steel pipework | Acidity coefficient (SiO₂ + Al₂O₃) / (CaO + MgO) | ≥1.8 | Below the value, the product leaches in humid service and shortens life | Fire classification | A1 (EN 13501-1) / Class A (ASTM E84) | Required for offshore, marine, and most commercial buildings | Inner diameter range | 18–1500 mm | Confirms the supplier can size to your line, not just DN 50–DN 300 | Length | 915 or 1000 mm standard | Standard lengths match standard jacket widths and reduce on-site cutting | Note that the "long-term service temperature" number depends on the binder, not the fibre. Standard phenolic binder starts to break down around 250 °C; the high-temperature binder grade (often a silica-modified system) is what allows the section to survive to 750 °C. If your line will ever sit above 250 °C, you must specify the high-temperature grade explicitly. Five Selection Dimensions Putting a rock wool pipe on order without a checklist is how projects end up with the wrong product. Use these five dimensions in order. 1. Temperature match. High-temperature lines above 400 °C want a high-density, high-temperature-grade section in the 120–200 kg/m³ range. Mid-temperature lines from 100 °C to 400 °C take the standard 100–120 kg/m³ grade. Low-temperature lines below 100 °C can use a lighter 80–100 kg/m³ grade, but you must check the water-vapour drive and the closed-cell requirement. 2. Environment adaptation. Humid, outdoor, underground, and marine service all require the hydrophobic grade with water repellency ≥98 % and water absorption ≤1 %. Corrosive or chloride-rich environments require the low-chloride product (Cl⁻ ≤ 0.05 %) so that rock wool does not initiate stress-corrosion cracking on austenitic stainless pipework. 3. Mechanical strength. Specifying the right density and compressive grade costs almost nothing and prevents the most common field failure: ovalisation of large-diameter pipe sections under their own weight between supports. For high-pressure process lines or lines that will be walked on for inspection, target ≥15 kPa compressive strength and consider external banding. 4. Installation practicality. Pre-cut, pre-scored sections install roughly 30 % faster than field-fabricated wraps. Where elbows, tees, and reducer sizes appear in volume, order matching elbows and bends rather than trying to cut straight sections to fit. For aluminium or glass-cloth facings, decide in the PO whether the facing is factory-laminated or applied on site — factory-laminated facings reduce on-site labour and keep the vapour barrier continuous. 5. Lifecycle economics. Cost per metre is the wrong metric. Use cost per linear metre per unit R-value over the planned service life. A high-density, high-temperature-grade section at a higher unit price often beats a low-cost section over a 20-year horizon because the low-cost section has to be replaced after the first wet cycle. Production: How Rock Wool Pipe Sections Are Made The line consists of five steps, and the quality of the finished section is set in two of them. 1. Raw-material preparation. Basalt, dolerite, and dolomite are selected for their SiO₂ + Al₂O₃ ratio; the target acidity coefficient is ≥1.8. The ore is crushed to ≤5 mm, dried to ≤0.5 % moisture, and stored under cover. Reject feed that is the raw material is the first guarantee of a stable product. 2. High-temperature melting. The mix is melted in a cupola or electric furnace at 1450–1600 °C into a homogeneous liquid. Furnace control sets the melt viscosity, which sets the fibre diameter three steps later. Reject melt that is overheating accelerates refractory wear in the furnace and creates shot. 3. Centrifugal fibre formation. The melt stream is fed to a four-roller centrifuge or high-speed centrifugal wheel running at 1400–2000 rpm. Centrifugal force draws the melt into fibres. Target fibre diameter is 4–6 µm; target shot content is ≤12 %, with premium products at ≤7 %. For more on the fibre-forming process, see our centrifugal glass wool manufacturing guide. 4. Binder application and curing. Phenolic resin binder is sprayed onto the fibre stream at 3–5 % of the finished weight; for hydrophobic grades, a silicone-based water-repellent additive is added at the same station. The collected fibre mat is then formed around a mandrel in a press and cured at 150–200 °C for 10–30 min. Curing temperature is the second decisive step — under-cure leaves a soft, dusty section; over-cure embrittles the fibre and reduces spring-back on site. 5. Cutting and finishing. After cure, the continuous tube is cut to standard lengths (typically 915 mm or 1000 mm), the wall thickness is checked against tolerance (single-point density tolerance ±5 %), and any required facing — aluminium foil, glass cloth, PVC — is laminated. Each section is coded with batch number, density, and date for traceability. A note on what the production line cannot fix: a wrong raw-material mix shows up as excess shot and weak fibre three steps later, and an out-of-tune centrifuge cannot be saved by adding more binder. Buy from a mill that publishes fibre-diameter and shot-content histograms with each batch, not just point values. Qualifying a Supplier A reliable supplier qualification looks at four dimensions, in this order. Adjust weights for your project. 1. Quality and certification. Require test reports from an independent laboratory covering thermal conductivity, density tolerance, shot content, water repellency, chloride content, and fire classification. Look for ISO 9001 quality management and ISO 14001 environmental management at the producing mill. Ask whether the mill is itself the producer or a fabricator buying raw board — this changes how quickly they can respond to non-conformance. 2. Production capability and lead time. Confirm the mill can run the density and inner-diameter you need, not just standard DN 50–DN 300 sizes. Confirm batch size and the minimum order quantity. Lead time for stock sizes is often 7–15 days for tier-1 regional mills and 2–3 weeks for international mills; allow longer for special densities or facings. 3. Technical support and traceability. A usable supplier answers technical questions in writing within hours, not days, and can trace any production batch back to the raw-material lot, the shift, and the operator. For larger projects, request that the supplier provide a sample of every delivery for in-house testing on receipt. 4. Commercial terms. Tier-1 international suppliers typically cost more per cubic metre but bring full documentation and predictable performance. Regional tier-2 mills are usually 30–60 % cheaper per cubic metre, with shorter lead times and more flexibility on batch size, but documentation may be thinner. For volume orders above about 2000 m³, tier-2 mills often offer step discounts and can schedule custom runs; for low-volume or specialty orders, tier-1 mills are usually the lower-risk choice. A practical risk check before signing a PO: ask for a recent third-party test report (issued within the last 12 months) covering the exact density and grade you intend to buy. A supplier that cannot produce one is telling you something important. Installation Notes Three details make or break an installed rock wool pipe section. Joint treatment. Stagger longitudinal joints at least 200 mm between adjacent sections; close circumferential joints with a gap of ≤5 mm. On elbows and bends, factory-cut matching elbows are much faster and tighter than field-cut straight sections. Vapour barrier. In humid, outdoor, or underground service, apply a continuous vapour barrier — aluminium foil facing on the section plus 50 mm aluminium foil tape at every joint and at every penetration. Breaks in the vapour barrier are where most moisture failures start. Compensation and expansion. Allow 1.2× the calculated pipe movement at expansion loops; wrap the loop with flexible rock wool blanket rather than rigid sections. On the outer jacket, seal all aluminium or colour-coated steel joints with sealant first and then cover with 50 mm foil tape. Conclusion Rock wool pipe insulation is a single-component, factory-controlled insulation system that delivers predictable performance from −240 °C up to 750 °C with the high-temperature binder grade. The specification table is short and well-defined; the production line is well-understood; supplier qualification is straightforward when you ask for batch test reports and traceability. Buy the grade that matches your temperature and environment, demand documentation rather than promises, and most projects run for decades without insulation becoming the failure mode. For the matching product on our line, see pre-formed rock wool pipe sections, or send your line list — pipe size, operating temperature, environment — and our engineers will return a sample plan and a quotation within two working days. Manufacturer & Supplier of Rock Wool Pipe Sections Qualifying a rock wool pipe insulation manufacturer comes down to one question: does the mill produce the stone wool, or buy board and fabricate? A producer controls the 650 °C continuous-use chemistry, the binder system and the dimensional tolerances of every DN size. What a rock wool pipe supplier should demonstrate - Mill-direct production of stone wool with documented density and shot-content control - ISO 9001 and CE certification, A1 non-combustible classification on the quoted line - Ability to run non-standard inner diameters and wall thicknesses, not just DN 50–DN 300 - Batch traceability and written technical response within hours Our rock wool pipe products - Rock Wool Pipe — pre-formed sections for heating, steam and process piping - Rock Wool Insulation hub for grades, densities and project data For mineral wool pipe insulation manufacturers enquiries, Rosewool runs the fibre line in-house and has supplied pipe sections to power, petrochemical and marine projects since 1982. Contact our engineering team for density selection, DN sizing and project specifications. Related products: Rockwool Pipe Insulation for Steam Pipes Related applications: Cryogenic Insulation FAQ: Q: What is rock wool pipe insulation? A: It is a pre-formed, half-rigid pipe section made from basalt-based mineral wool fibre, factory-cured with phenolic binder. It is shaped as a hollow cylinder, slit along one side, and supplied in standard 915 mm or 1000 mm lengths. Compared with field-wrapped blanket, it installs faster and gives more consistent thermal performance across the pipe. Q: What is the maximum service temperature of rock wool pipe insulation? A: With the standard phenolic binder, the long-term service limit is about 250 °C. With the high-temperature binder grade, the limit extends to 750 °C for continuous service. Short-term peaks to 1000 °C are tolerated for up to 30 minutes, which covers start-up, flame-duct excursions, and emergency shutdowns. Q: What thermal conductivity can I expect? A: Tested to ASTM C518 at a mean temperature of 70 °C, typical rock wool pipe insulation is at or below 0.035 W/(m·K). λ rises with mean temperature and with density, so design calculations at higher mean temperature should use the manufacturer's published curve rather than the 70 °C point. Q: What density should I specify? A: For most industrial pipe at moderate temperature, 100–120 kg/m³ balances thermal performance, mechanical strength, and weight. For high-temperature process lines above 400 °C, 120–200 kg/m³ gives better compressive strength and lower shrinkage. For HVAC and domestic service below 100 °C, 80–100 kg/m³ is usually sufficient if the vapour barrier is intact. Q: Is rock wool pipe insulation waterproof? A: Standard rock wool is not waterproof. The hydrophobic grade, made by adding a silicone-based water repellent during binder application, delivers water repellency ≥98 % and water absorption ≤1 % by weight. Hydrophobic grade is required for outdoor, marine, underground, and other wet service. The facing on the section is the vapour barrier; joints and penetrations must be taped. Q: What is the standard length and diameter range? A: Standard lengths are 915 mm and 1000 mm. Inner diameters typically cover DN 18 to DN 1500, with custom sizes available from most mills for volume orders. Wall thickness ranges from 25 mm to 200 mm depending on the required thermal resistance and pipe size. Q: What fire rating does rock wool pipe insulation carry? A: Quality rock wool pipe sections are non-combustible and classified A1 under EN 13501-1 and Class A under ASTM E84. The classification is for the section itself, including the standard facing. Aluminium foil facings do not reduce the fire rating; PVC facings require separate evaluation. Q: How is rock wool pipe insulation made? A: The production line has five steps: raw-material preparation (basalt/dolerite/dolomite crushed and dried), melting in a cupola or electric furnace at 1450–1600 °C, centrifugal fibre formation at 1400–2000 rpm with target fibre diameter 4–6 µm, binder application plus curing at 150–200 °C for 10–30 min, and cutting to length plus optional facing lamination. Two steps set the quality: melt control, which determines fibre diameter and shot content, and curing control, which determines mechanical strength and surface finish. Q: What certifications should a mill have? A: For most industrial and commercial projects, the producing mill should hold ISO 9001 (quality management) and the product should carry a third-party test report (within the last 12 months) covering thermal conductivity, density tolerance, fire classification, water repellency (for hydrophobic grade), and chloride content. ISO 14001 is a useful plus for projects with environmental specifications. Marine and offshore projects typically require additional class-society salt-spray and fire testing. Q: What should I check on receipt of a delivery? A: Check the batch label against the PO (density, grade, dimensions), inspect a sample from the for damage in transit, and verify water repellency on hydrophobic grade with a simple surface-water test. For critical service, retain one section per delivery for laboratory re-test at the end of the project, not for current use. ### Insulation Glossary: A1, Calsil, Pyrogel, Microporous Explained URL: https://www.rosetexwool.net/news/insulation-glossary-a1-calsil-pyrogel-microporous/ 2026-09-06 | Author: Rosetexwool Editorial | Category: industry insight Summary: Plain-English definitions of four key industrial insulation terms: A1 fire rating, Calsil calcium silicate, Pyrogel aerogel, and microporous insulation — plus a comparison table and selection guide. Industrial insulation specifications are full of shorthand: A1, Calsil, Pyrogel, Microporous. Each term points to a different material class, and picking the wrong one for a given temperature or fire requirement can cost energy, safety, or project budget. This glossary explains what each term actually means, where the terms overlap, and how to choose among them. A1 — The Non-Combustible Fire Rating A1 is the top fire-performance class under EN 13501-1 and the equivalent grade in China's GB 8624-2025 system. An A1-rated material is non-combustible: it does not burn, does not produce flaming droplets, and has very low smoke development. Key points: - Organic content is typically ≤1%. - Common A1 insulation materials include rock wool, glass wool, calcium silicate (Calsil), and ceramic fiber. - A1 is a fire classification, not a material type. Two products with very different thermal performance can both be A1. For any public building, hospital, school, high-rise, or enclosed process area where fire safety is regulated, A1 is usually the minimum acceptable rating. Calsil — Rigid Calcium Silicate Insulation Calsil is short for calcium silicate insulation — a rigid, inorganic board or pipe-section material made from lime (CaO) and silica (SiO₂) cured under high-pressure steam. The resulting crystal structure (usually tobermorite or xonotlite) gives it low thermal conductivity plus enough strength to carry light loads. Typical grades and properties: Grade | Service temp | Density | Thermal conductivity (25°C) | Compressive strength | Standard | up to 650°C | 170–240 kg/m³ | ~0.048–0.060 W/m·K | ≥0.5 MPa | High-temp | up to 1000–1050°C | 220–300 kg/m³ | ~0.056–0.062 W/m·K | ≥1.0 MPa | Use Calsil when you need a rigid, structural back-up layer — for example behind a hot-face ceramic fiber lining, under pipe support shoes, or as a flat, walkable insulation surface. For a deeper dive, see our Calsil FAQ. Pyrogel — Aerogel-Based Blanket Insulation Pyrogel is one of the best-known brand names for silica aerogel blanket insulation. In everyday specification language, "Pyrogel-type" has become shorthand for high-performance aerogel blankets — thin, flexible, hydrophobic, and extremely low in thermal conductivity. Key properties: - Thermal conductivity: ~0.017 W/m·K at 25°C; ~0.025–0.030 W/m·K at 250°C. - Service temperature: typically −90°C to 650°C continuously; short peaks to ~1200°C. - Density: 160–220 kg/m³. - Hydrophobicity: water-repellent (>95% typically), which reduces corrosion-under-insulation (CUI) risk. - Form: flexible blanket, easy to wrap around valves, flanges, and curved pipes. The trade-off is price: aerogel blankets cost several times more than mineral wool per square metre. They pay back fastest where space is tight, access is difficult, or CUI shutdowns are expensive. For a full comparison, read our Pyrogel vs Mineral Wool Pipe Insulation guide. Microporous — Nano-Scale Pore Insulation Microporous insulation uses a solid matrix filled with pores smaller than the mean free path of air molecules (typically <50 nm, often in the 0.2–2 nm IUPAC micropore range). Because the pores are so small, gas molecules cannot move freely, so heat transfer by convection and gas conduction is suppressed. Key properties: - Thermal conductivity: 0.020–0.040 W/m·K at room temperature; ≤0.065 W/m·K at 1000°C. - Service temperature: roughly −200°C to 1150°C, depending on the chemistry. - Density: 220–350 kg/m³. - Forms: rigid boards, flexible panels, pipe sections, and custom-molded shapes. - Composition: alumina-based, silica-based, or calcium-silicate-based, often with reinforcing fibers. Microporous sits between aerogel and Calsil on the performance/cost map: thinner than Calsil, more mechanically robust than aerogel, and rated for higher continuous temperatures than Pyrogel-type blankets. Comparison Table Property | A1 (fire class) | Calsil | Pyrogel-type aerogel | Microporous | What it is | Fire rating | Rigid calcium silicate | Silica aerogel blanket | Nano-pore rigid/flexible insulation | Max continuous temp | varies by material | 650–1050°C | ~650°C | up to ~1150°C | Conductivity at 25°C | — | 0.048–0.062 W/m·K | ~0.017 W/m·K | 0.020–0.040 W/m·K | Density | — | 170–300 kg/m³ | 160–220 kg/m³ | 220–350 kg/m³ | Compressive strength | — | high (load-bearing) | low | moderate | Flexibility | — | rigid | flexible | board or flexible grades | Hydrophobic | — | water-resistant | hydrophobic | water-resistant | Fire rating | A1 | A1 | A1 | A / A1 | Best for | fire compliance | structural back-up, pipe supports | tight spaces, CUI risk, hot valves | high-temp equipment, thin linings | How to Choose - Need only fire compliance on a budget → A1-rated rock wool board or glass wool. - Need a rigid, load-bearing back-up layer behind the hot face → Calsil board or pipe section. - Space is tight, CUI is a concern, or valves/flanges need frequent access → Pyrogel-type aerogel blanket. - Continuous temperature is above 650°C and you need thinner sections than Calsil → microporous board or flexible microporous panels. In practice, many high-temperature linings are hyid: ceramic fiber or rock wool on the hot face, Calsil or microporous as the structural back-up, and aerogel blankets at critical details like flanges and valves. Related products: Calcium Silicate Pipe, Ceramic Fiber Rope Related applications: Green Building & Retrofit FAQ: Q: What does A1 mean in insulation? A: A1 is the highest fire-performance class under EN 13501-1 and GB 8624-2025. An A1 insulation material is non-combustible, produces no flaming droplets, and has very low smoke development. Rock wool, glass wool, Calsil, and ceramic fiber can all be manufactured to A1. Q: Is Calsil the same as calcium silicate? A: Yes. Calsil is simply industry shorthand for calcium silicate insulation — a rigid board or pipe-section material made from lime and silica. It is valued for its load-bearing strength and service temperatures up to 650°C (standard grade) or 1000–1050°C (high-temp grade). Q: Is Pyrogel a brand or a material type? A: Pyrogel started as a brand name for silica aerogel blanket insulation, but in many industries it is used as shorthand for high-performance aerogel blankets in general. When specifying, it is safer to ask for aerogel blanket performance values (conductivity, density, max temp, water repellency) rather than assuming a single brand. Q: What is microporous insulation used for? A: Microporous insulation is used where very low thermal conductivity is needed at high temperatures — typically −200°C to 1150°C. Common uses include industrial furnaces, ladles, tundishes, reaction vessels, and any equipment where a thinner lining than conventional materials would allow is desirable. Q: Which is better: Calsil, Pyrogel, or microporous? A: There is no universal winner. Calsil wins on rigidity and cost. Pyrogel-type aerogel wins on thinness and water resistance at moderate temperatures. Microporous wins when continuous temperatures exceed roughly 650°C and a thin section is still required. Most industrial linings combine two or more materials. ### Pyrogel vs Mineral Wool Pipe Insulation: Real Comparison URL: https://www.rosetexwool.net/news/pyrogel-vs-mineral-wool-pipe-insulation/ 2026-09-06 | Author: Rosetexwool Editorial | Category: industry insight Summary: Pyrogel vs mineral wool pipe insulation: thermal conductivity, thickness, CUI risk, installed cost, and real payback data for steam and process lines. Quick Answer For industrial piping, the choice between a Pyrogel-type aerogel blanket and a mineral wool pipe section is not about temperature limit — both cover roughly −40 °C to 650 °C continuously. The real differences are thickness, hydrophobicity, and lifecycle cost. - Pyrogel / aerogel wins when space is tight, CUI risk is high, or the line runs hot for long hours. It needs roughly one-third to one-half the thickness of mineral wool and rejects water at the material level. - Mineral wool / rock wool pipe wins on first cost and acoustic absorption. It is still the default for budget-driven, dry-indoor, large-bore steam lines where there is room for the thicker insulation and a reliable vapor barrier. Before comparing products, fix the form: our guide to choosing a pipe insulation type before comparing products sets out preformed sections against wrapped blanket, and single layer against double. A common hybrid is aerogel at valves, flanges, and CUI-critical sections plus mineral wool on straight pipe runs. Core Parameter Comparison Property | Pyrogel-type aerogel blanket | Mineral wool / rock wool pipe section | Continuous service temperature | −40 °C ~ 650 °C | ~650–750 °C (binder degradation starts above ~250 °C; common service 350–450 °C) | Thermal conductivity λ at 25 °C | 0.020–0.025 W/(m·K) | 0.034–0.044 W/(m·K) | Equivalent-insulation thickness | Baseline (1×) | ~2–3× thicker | Density | 150–250 kg/m³ | 80–200 kg/m³ (common 100–150) | Hydrophobic behavior | Inherently hydrophobic and breathable | Hydrophilic unless treated; relies on outer jacket | Compressive strength | Low (~100 kPa); needs load-bearing pads at supports | Higher; rigid pipe section | Flexibility / fittings | Excellent for valves, elbows, flanges | Rigid; fittings need custom cuts | Fire reaction | A-grade non-combustible | A1-grade non-combustible | Typical service life | 20+ years | 5–10 years in wet/cyclic service, 15–30 years in dry service | Material cost | 3–10× mineral wool | Lowest first cost | Key takeaway: mineral wool is cheaper to buy; aerogel is cheaper to own when energy, space, weight, and maintenance are counted. Why Thermal Conductivity Alone Is Misleading Every insulation material gets worse as temperature rises. Solid conduction, gas conduction, and radiative heat transfer all increase. So the number that matters is the thermal conductivity at the pipe's operating temperature, not the 25 °C catalog value. Representative values by mean temperature: Mean temperature | Pyrogel-type aerogel λ | Mineral wool pipe λ | 25 °C | 0.021 W/(m·K) | 0.040 W/(m·K) | 150 °C | 0.030 W/(m·K) | 0.050 W/(m·K) | 300 °C | 0.038 W/(m·K) | 0.065 W/(m·K) | 500 °C | 0.055 W/(m·K) | 0.090 W/(m·K) | The absolute gap narrows at high temperature because radiation becomes dominant in both materials, but the thickness advantage of aerogel stays roughly 1.5–2× even at 500 °C and 2–3× at moderate temperatures. Thickness & Space: The Engineering Difference The table below shows the thickness needed for the same thermal resistance on a typical process pipe: Service condition | Pyrogel-type aerogel | Mineral wool | Medium-temperature pipe (~150 °C) | 3–15 mm | 25–40 mm | High-temperature pipe (~300 °C) | 15–25 mm | 40–60 mm | Cryogenic / chilled pipe | 20–30 mm | Multiple thick layers | Thin insulation creates a chain of benefits: - Tighter pipe racks — more lines in the same corridor - Lower structural load — often 80–90% less insulation weight per meter - Smaller outer jacket — less metal cladding - Easier maintenance — flexible blankets wrap and unwrap faster around valves and flanges The trade-off is compressive strength. Rock wool pipe sections carry their own weight at pipe supports; aerogel needs a load-distribution pad at clamps and saddles. CUI: The Cost Nobody Puts in the First Quote Corrosion under insulation (CUI) is often the largest hidden cost. Standard mineral wool is an open-cell, hydrophilic fiber. If the outer jacket leaks, water is trapped against the steel. A hot carbon-steel pipe plus water plus oxygen produces rapid pitting — often discovered only after perforation. Pyrogel-type aerogel blankets are different: - The silica aerogel structure is inherently hydrophobic, not surface-coated - The material is breathable, so any moisture that enters can evaporate instead of pooling - Performance stays stable after wet–dry cycles That does not mean mineral wool is unusable outdoors. With a robust outer jacket, a vapor barrier, and a corrosion-inhibitor treatment, mineral wool can give acceptable CUI performance. But the system must be designed and inspected; the material alone is not the defense. Cost & Lifecycle Payback Cost driver | Pyrogel-type aerogel | Mineral wool | Material unit price | 3–10× higher | Lowest | Outer metal cladding | Less (thin layer) | More (thick layer) | Pipe support / rack load | Lower | Higher | Labor / installation time | Faster (fewer layers, flexible) | Slower (multiple layers, rigid sections) | Energy loss over 20 years | Lower | Higher | CUI repair / replacement | Rare | Periodic in wet service | Typical payback observed on industrial projects: - Hot steam / process lines: 18–36 months - High-value energy recovery: 6–14 months - Underground / flood-prone valve stations: often under 12 months The premium is recovered through four channels: lower heat loss, less cladding metal, fewer shutdowns for CUI repair, and avoided catastrophic pipe replacement. What Real Projects Show Three patterns appear repeatedly in field reports: - Underground steam distribution A university district heating network replaced mineral wool with aerogel in flooded valve pits. Heat-loss cost per pit dropped by over 90%, and the network avoided installing additional boiler capacity. Payback was under one year. - Delayed coker feed line A refinery had repeated cold spots and frequent pigging on a coker feed line insulated with calcium silicate. After switching to a Pyrogel-type aerogel, pigging frequency fell sharply and annual maintenance savings were roughly USD 600,000. Field measurements showed 50 mm of aerogel delivered equivalent performance to 150 mm of mineral wool. - Alumina plant fire-water pipe rack A 300 °C fire-water line on an exposed rack suffered repeated insulation failure and process trips during rain. After installing an aerogel blanket, the line remained thermally stable in heavy weather and the material was written into the site specification. Note: These cases are drawn from published contractor and end-user reports. Specific site conditions, energy prices, and maintenance practices affect results. Always size insulation with the actual service temperature and lifecycle cost model. Selection Decision Framework Choose Pyrogel / aerogel when - Pipe rack space is constrained (offshore modules, ship engine rooms, dense corridors) — see also rock wool for marine & offshore engineering - CUI risk is high: carbon steel, outdoor/wet cycling, buried or flood-prone valves - The line operates above 300 °C for more than 6,000 hours per year - Frequent access to valves, flanges, and instrumentation is required - Weight savings justify the material premium (LNG modules, retrofit racks) Choose mineral wool / rock wool when - Budget is the primary constraint - The line is indoors, dry, and has plenty of clearance - Acoustic absorption is also required (turbine halls, boiler houses) — see rock wool for power-generation applications - Large-diameter straight runs dominate the scope - A competent inspection and maintenance program for CUI is in place Practical hybrid design - Straight runs: rock wool pipe sections for economy - Valves, flanges, and CUI hotspots: aerogel blankets in removable jackets - Supports and clamps: load-bearing pads under aerogel; calcium silicate pipe or high-density rock wool where compression is unavoidable For the same two materials compared on cost per R-value and lifecycle payback for tanks, vessels and general plant equipment — outside the piping context — see our pyrogel vs mineral wool comparison. Final Take There is no universal winner. Pyrogel-type aerogel is the technical optimum where space, weight, CUI, or energy loss dominate. Mineral wool remains the commercial default where first cost and dry-indoor conditions dominate. The best industrial specs increasingly treat them as complementary: mineral wool for the long straight runs and aerogel for the complex, high-risk, high-value sections. At Rosewool Insulation Refractory Co., Ltd., we manufacture rock wool pipe sections, calcium silicate pipe covers, and nano-aerogel insulation systems for industrial piping. Since 1982, ISO 9001 / CE / SGS certified, exporting to 50+ countries. Contact us for a thickness and payback calculation based on your actual pipe temperature and energy cost. Related products: Rockwool Pipe Insulation for Steam Pipes, Nano Aerogel Insulation Blanket Related applications: Building, Aerospace & Defense, Iron & Steel FAQ: Q: Is Pyrogel the same as aerogel insulation? A: Pyrogel is a well-known trade name for a silica-aerogel blanket used in industrial insulation. In many project specs, 'Pyrogel' is used as shorthand for flexible aerogel pipe wrap, similar to how some product categories become generic terms. The article treats Pyrogel as a representative aerogel blanket. Q: How much thinner is Pyrogel than mineral wool for the same insulation value? A: At moderate temperatures (~150 °C), Pyrogel-type aerogel needs roughly one-third to one-half the thickness of mineral wool. At 300 °C and above, the advantage narrows but still stays around 1.5–2×. Exact thickness must be calculated with the service temperature and the product's λ at that temperature. Q: Can I use mineral wool pipe insulation outdoors without CUI problems? A: You can, but only if the complete system is designed for it: a watertight outer jacket, a vapor barrier, corrosion-inhibitor-treated wool, and periodic inspection. Standard mineral wool alone is hydrophilic and will trap water against the pipe if the jacket leaks. Q: When does Pyrogel pay back compared with rock wool? A: On hot process or steam lines running more than 6,000 hours per year, payback is commonly 18–36 months. Payback is faster where energy prices are high, space is expensive, or CUI repair costs are significant. On short, low-temperature, indoor lines, rock wool usually wins on first cost. Q: Can rock wool pipe and aerogel be used together on the same line? A: Yes. A common hybrid is rock wool pipe sections on straight runs plus aerogel blankets on valves, flanges, and CUI-critical zones. Another hybrid is aerogel as the inner layer and rock wool as the outer layer for combined thermal performance and economy. Q: What is a good pyrogel alternative? A: For the same duty, mineral wool (rock wool) pipe sections are the main budget alternative — they cost far less but need roughly 2–3× the thickness. Rigid calcium silicate pipe is the load-bearing option, and a nano-aerogel blanket is the same-performance-class alternative where space or CUI risk dominates. Q: What is rigid pyrogel? A: Rigid pyrogel-type products are aerogel blankets bonded onto a rigid substrate or supplied as high-density aerogel board. They keep the ultra-low conductivity of the blanket but can bear compression and stand alone, which makes them useful at pipe supports, flanges, and equipment casings where a flexible blanket would crush. Q: How thick is pyrogel pipe insulation? A: For the same thermal resistance, roughly one-third to one-half the thickness of mineral wool: about 3–15 mm on a medium-temperature pipe (~150 °C), 15–25 mm at ~300 °C, and 20–30 mm in cryogenic service. Exact thickness depends on pipe diameter, operating temperature, and the allowed heat loss. ### Refractory Insulation Materials: Types, Ratings & Applications URL: https://www.rosetexwool.net/news/refractory-insulation-materials-types-ratings-applications/ 2026-09-06 | Author: Rosetexwool Editorial | Category: industry insight Summary: Refractory insulation materials explained: ceramic fiber, PCW, calcium silicate, rock wool and microporous grades compared by rating, conductivity and applications. Industrial high-temperature equipment lives in a particular band of temperatures where the insulating material must do two jobs at once — keep the heat inside the process and keep its own shape while doing it. Materials that meet this dual requirement sit in a category the industry calls refractory insulation materials (or, when the dual role is explicit, insulating refractory). This article is a practical map of that category: where the boundary lies between "refractory" and "plain insulation", which families dominate the band between 800 °C and 1,800 °C, how each family is rated, and how engineers actually pick one. 1. What "Refractory Insulation" Actually Means The word refractory has a strict, technical definition. A refractory is a non-metallic material that resists high temperature without melting or deforming under load, usually defined in laboratory pyrometric-cone equivalents (ISO 2245 and ASTM C24 both set the entry bar around 1,500 °C). That is the language used in furnaces, kilns and metallurgical vessels. In industrial insulation practice, the term refractory insulation material is used more loosely to mean a material that is rated for service at or above 800 °C and that also delivers useful thermal-insulation performance — typically a thermal conductivity well below 0.10 W/(m·K). The 800 °C line is a pragmatic threshold used by procurement and engineering teams to separate these "hot-face" grades from regular industrial insulation such as standard rock wool or mineral wool pipe sections. The key point is that the material has to do both jobs: take the heat, and stop the heat moving through it. Traditionally, refractories were dense and load-bearing, made to last at 1,500 °C-plus temperatures in furnaces where they carried structural load. Insulating refractories trade some of that load capacity for low thermal conductivity — they are light, low-density, and sit behind or alongside a denser working lining. 2. The Six Families That Dominate 800 °C and Above Six material families cover almost every practical application in this temperature band. The differences come down to chemistry, maximum service temperature, density and cost. Family | Main chemistry | Long-term limit | Short-term peak | λ at 400 °C (W/(m·K)) | Bulk density (kg/m³) | Dominant uses | Ceramic fiber (aluminosilicate) | SiO₂ 43–55 %, Al₂O₃ 45–57 % | 800–1,260 °C | to 1,430 °C (high-alumina) / 1,600 °C (zirconia-bearing) | 0.035–0.080 | 64–200 | Furnace linings, pipe wraps, reformer tubes | Polycrystalline wool (PCW) | Al₂O₃ 72–97 % | 1,260–1,700 °C | 1,800–1,900 °C | 0.045–0.075 | 80–400 | Petrochemical crackers, ceramic kilns, re-entry hardware | Calcium silicate | CaO + SiO₂ | 800–1,100 °C | – | 0.045–0.065 | 170–1,000 | Cement kilns, glass tanks, fire-rated boards | Microporous calcium silicate | CaO + SiO₂ + opacifiers | 950–1,100 °C | – | 0.020–0.035 | 170–230 | Process piping, distillation columns | Rock wool, high-temperature grade | SiO₂ 44–66 %, Al₂O₃ 15–25 % | 600–800 °C | – | 0.035–0.055 | 40–200 | Industrial pipework, fire walls | Aerogel composite blanket | SiO₂ aerogel + fiber matrix | to ~1,000 °C | – | 0.020–0.025 | 130–180 | Thinnest envelope, retrofit upgrades | Two practical observations follow directly from this table. First, rock wool stops at about 800 °C — above that, ceramic fiber or PCW is the only realistic choice. Second, where the application crosses 1,400 °C in continuous service, ceramic fiber gives way to PCW (or to a layered construction with dense refractories behind). Our PCW modules guide covers the install side of that band in detail. For the 1600 °C-and-above band where even PCW reaches its edge, see our guide to alumina zirconia ultra-high-temperature fiber. 3. "Refractory" vs "Insulation" — Two Functions in One Material The defining feature of the category is the dual function. A traditional dense refractory brick may be excellent at 1,500 °C, but its thermal conductivity is typically 0.8–1.2 W/(m·K) at 400 °C — meaning a lot of heat walks straight through. An insulating refractory in the same temperature bracket may sit at 0.04–0.08 W/(m·K), an order of magnitude lower. Function | Traditional dense refractory | Insulating refractory | Plain industrial insulation | Service temperature | ≥1,500 °C | 800–1,700 °C | up to ~700 °C | Thermal conductivity at 400 °C | 0.8–1.2 W/(m·K) | 0.04–0.10 W/(m·K) | 0.030–0.060 W/(m·K) | Bulk density | 2,500–3,200 kg/m³ | 150–1,000 kg/m³ | 30–200 kg/m³ | Main role | Structural containment + heat | Containment + insulation (no major load) | Insulation only | Typical form | Brick, castable, monolithic | Brick, board, blanket, microporous | Pipe section, blanket, panel | The trade is mechanical strength: insulating refractories are lighter and weaker, so they are usually paired with a denser working lining or with mechanical anchors. The heat-loss saving is large enough that, in almost every retrofit or rebuild, this trade is worthwhile. 4. Rating Systems and How to Read Them Three rating systems appear most often on supplier datasheets, and they answer different questions. - Refractoriness (ISO 2245 / ASTM C24): the pyrometric cone equivalent temperature, in other words the temperature at which a standard sample deforms under its own weight. This is the strict refractory number — almost always ≥1,500 °C for any material sold as a true refractory. - Classification of insulating refractories (ISO 2246 / ASTM C401): groups insulating refractory products by bulk density, thermal conductivity and permanent linear change. This is where you find grades labelled "type 1.0", "type 1.4" and so on, with the number being the nominal density in g/cm³. - Maximum service temperature (manufacturer-rated): the temperature the material can withstand in continuous service while still meeting its published conductivity and shrinkage limits. For ceramic fiber this is usually 1,050–1,260 °C; for PCW it climbs to 1,400–1,700 °C. Industrial procurement usually works to this number, not to the cone equivalent. A practical reading rule: if a datasheet quotes only a cone equivalent but no service temperature, ask before you buy. The cone number tells you the material will not melt; it does not tell you it will keep its thickness or its conductivity at the temperature you actually need. 5. The Selection Decision Matrix A five-step selection usually covers the whole problem. - Working conditions. Maximum continuous temperature, temperature cycling, atmosphere (oxidising, reducing, alkaline, acidic), mechanical load and any vibration. - Material family. Match the temperature band (Section 2) to one of the six families. If the answer is "ceramic fiber", choose between standard, high-alumina and zirconia-bearing grades. If the answer is "PCW", choose between PCW bulk fiber and PCW modules. - Thermal performance. Look at the λ-versus-temperature curve, not just a single-point value. Microporous boards win at moderate temperatures; ceramic fiber wins at 800–1,300 °C; PCW wins above 1,300 °C. - Chemistry. Alkaline environments favour calcium silicate; reducing atmospheres and petrochemical service favour PCW or high-alumina ceramic fiber; aluminium reduction cells (the classic application shown in the image above) are a textbook case for microporous calcium silicate board. - Economy. Balance material cost against energy saved. For a continuous furnace at 1,200 °C, switching from dense firebrick to high-alumina ceramic fiber blanket typically reduces shell losses by 60–80 %. Application | Working temperature | Atmosphere | Recommended family | Typical form | Steel reheating furnace | 1,100–1,350 °C | Oxidising | High-alumina ceramic fiber | Blanket, module, board | Petrochemical cracking furnace | 1,200–1,400 °C | Reducing | PCW or zirconia-bearing ceramic fiber | Module, blanket | Cement rotary kiln (outer layer) | 1,400–1,500 °C | Alkaline | Calcium silicate board | Rigid board | Glass melting tank | 1,500–1,600 °C | Alkaline + carry-over | PCW + calcium silicate composite | Board behind dense lining | Aluminium reduction cell | 950–1,000 °C | Cryolite + fluoride | Microporous calcium silicate board | Rigid board | Power-station boiler (HRSG) | 800–1,100 °C | Oxidising | High-temperature rock wool or microporous | Pipe section, board | Our broader industrial pipe insulation guide covers the system-side questions of where each of these grades sits in a complete pipe or duct assembly. Three mistakes appear repeatedly in refractory insulation specifications and are worth flagging up front. - Quoting the cone equivalent as the service temperature. A refractory with a 1,790 °C cone equivalent can still fail in service at 1,300 °C if it has been rated only for short exposure. Always confirm the maximum continuous service temperature separately. - Mixing chemistries on the same hot face. Zirconia-bearing ceramic fibre and standard aluminosilicate fibre look identical but have different shrinkage behaviour. Use the same family in one lining to avoid differential shrinkage between hot and cold panels. - Ignoring the cold-side skin temperature. The point of an insulating refractory is to keep the shell temperature low enough to touch and to reduce heat loss. If the chosen material does not bring the shell below ~60 °C in the actual ambient, the engineering objective has not been met, regardless of how well the hot face performs. 6. Why Insulating Refractory Matters: Heat-Loss Economics For a continuously operating furnace, the casing heat loss is usually 5–15 % of the heat input when built with dense firebrick. Switching the outer layers to insulating refractories usually drops that figure to 2–5 %, with the exact number depending on the lining thickness and the chosen material. A worked comparison for a 1,200 °C steel reheating furnace (illustrative figures only): Lining construction | Hot-face temperature | Casing temperature | Heat flux through wall | 230 mm dense firebrick only | 1,200 °C | ~180 °C | ~3,500 W/m² | 115 mm dense firebrick + 50 mm high-alumina ceramic fiber blanket | 1,200 °C | ~85 °C | ~1,200 W/m² | The payback on the upgrade typically falls in the 1–3-year range for a continuously operating furnace, with the exact figure driven by fuel cost, hours of operation and the cost of the chosen insulating layer. 7. Forms and Shapes in Practice Within each family the material is supplied in several physical forms, and the choice of form is often as important as the choice of chemistry. - Blanket — flexible, supplied in rolls; used where the surface is irregular or where the installation wraps around ducts and pipework. Anchored with studs and washers, or impaled on existing anchors. - Board — rigid panels cut from the same fibre or from calcium silicate; used where a flat surface is needed, for example behind a brick lining or as a back-up layer in a furnace wall. Which refractory board belongs where is decided less by conductivity than by duty: our furnace lining board selection guide works through position, cycling and chemical exposure in order. - Module — pre-compressed folded or layered fibre blocks, typically 200–300 mm thick, anchored with a built-in ceramic or alloy stud. Common in petrochemical cracker linings because installation speed matters and the post-installation expansion seals the joints. - Microporous board — rigid calcium-silicate-based panels with opacifiers that block radiation at moderate temperatures. Where shell size is tight and the surface temperature must be kept low, this is often the first choice for process piping. - Castables and gunning mixes — monolithic refractories poured or sprayed in place, used where geometry is complex or where the lining has to be repaired without a full shutdown. - Felt and paper — thin flexible sheets for gaskets, expansion joints and small-format insulation in instruments and laboratory equipment. For any form that involves fibre, the installation team needs adequate dust protection, and the supplier should provide a product safety datasheet for the specific grade. Our polycrystalline wool versus standard ceramic fiber comparison explains when PCW's higher temperature rating justifies its higher cost. 8. Health, Safety, and Compliance Refractory ceramic fibres (RCF) and some older alkaline-earth silicate (AES) wools have been classified in some jurisdictions as substances that should be handled with care. Two practical points follow. - Installation dust control. Cutting, machining or gunning fibre products generates airborne dust. Wet cutting, local exhaust ventilation and appropriate respiratory protection are standard practice on industrial sites. These are well-known controls in any high-temperature insulation installation and not unique to one supplier. - Newer low-bio persistence alternatives. Alkaline-earth silicate (AES) wool and certain biosoluble fibre grades are designed to clear from the lung more rapidly than traditional RCF. Where local regulations push in that direction, AES or biosoluble grades can be specified with a thermal-performance penalty that is usually small. Procurement teams should ask for the product safety datasheet, the country-of-origin certification, and confirmation of compliance with REACH (EU) and OSHA occupational exposure limits (US) before placing an order, regardless of which family is selected. On the operational side, three practices are worth standardising in any refractory insulation installation. - Pre-job planning. Confirm the lining drawing, anchor pattern and storage layout before the material arrives on site. Most delays in furnace lining jobs come from missing anchors or from insulation delivered in the wrong thickness. - Air monitoring during work. Personal dust sampling is standard practice on industrial sites for any project that disturbs fibrous insulation. The samples are quick to take and they protect both the workforce and the contractual record. - Lifecycle tracking. Each lining should be tagged with installation date, supplier batch and the operating conditions of the campaign. When the next shutdown arrives, this record is the only reliable basis for deciding whether the lining can be repaired in place or has to come out. 9. Conclusion Refractory insulation materials are not a single product. They are a family of inorganic materials — ceramic fibre, polycrystalline wool, calcium silicate, high-temperature rock wool, microporous boards and aerogel composites — that together cover the temperature band from 800 °C to roughly 1,800 °C. The right pick is rarely "the best insulator"; it is the best match between temperature, chemistry, mechanical load and economics for the specific lining. The selection matrix in Section 5, the top-10 high-temperature insulation materials round-up, and the high-density calcium silicate board properties and uses reference together cover most procurement questions that come up in this band. Rosewool supplies ceramic fibre, PCW, calcium silicate, rock wool and microporous insulation from a single manufacturing base established in 1982, certified to ISO 9001, CE and SGS. For a furnace-zone approach to refractory insulation material selection, see Alumina & AES refractory insulation applications. For a specification matched to your operating temperature, atmosphere and lining geometry, send the project brief to our technical team — typical material recommendation, thickness calculation and quotation are returned within one working day. For product-level specifications and datasheets, see our ceramic fiber bulk, ceramic fiber blanket, PCW fiberboard and calcium silicate insulation board product pages. FAQ: Q: What is a refractory insulation material? A: A refractory insulation material is an inorganic non-metallic product rated for continuous service at or above 800 °C that also delivers useful thermal-insulation performance, usually a thermal conductivity well below 0.10 W/(m·K). It is dual-purpose: it resists high temperature and reduces heat loss at the same time. Q: What is the difference between refractory and insulating refractory? A: A traditional refractory is a dense, load-bearing material rated for very high temperatures (typically above 1,500 °C) and its main job is to contain the heat. An insulating refractory, also called insulating firebrick or IFB, trades some of that load capacity for low thermal conductivity — it is lighter and reduces heat loss, but it is not designed to carry the same structural loads. Q: At what temperature is insulation classified as refractory? A: In strict technical language, refractory materials are defined by pyrometric-cone equivalents at or above 1,500 °C under ISO 2245 and ASTM C24. In industrial insulation practice, however, materials rated for service at or above 800 °C are usually grouped as refractory insulation grades, and that 800 °C threshold is widely used for procurement. Q: What is the maximum service temperature of ceramic fiber insulation? A: Standard aluminosilicate ceramic fibre is rated for continuous service up to about 1,050–1,260 °C depending on the Al₂O₃ content. High-alumina grades reach 1,260–1,350 °C, and zirconia-bearing grades can be used up to about 1,430 °C in continuous service, with short peaks to roughly 1,600 °C. Q: Is polycrystalline wool (PCW) the same as refractory ceramic fiber? A: PCW is a member of the refractory ceramic fibre family but a higher-performance grade. Where standard ceramic fibre is glassy aluminosilicate rated to about 1,260 °C, PCW is a crystalline alumina-mullite composition rated to 1,260–1,700 °C in continuous service, with short peaks to 1,800–1,900 °C. It is more expensive but holds its thickness and conductivity where standard fibre would shrink. Q: What is the best insulation for a petrochemical cracking furnace? A: For ethylene and hydrocarbon cracking furnaces running at 1,200–1,400 °C under reducing atmosphere, the standard choice is PCW modules or high-alumina ceramic fibre blanket, anchored with ceramic or high-temperature alloy studs. PCW modules are typically preferred above 1,300 °C because they resist shrinkage under continuous hot-face load. Q: How do you choose between rock wool and ceramic fiber above 800 °C? A: Above 800 °C, rock wool in its standard grades starts to lose mechanical integrity and to sinter, while ceramic fibre keeps its thickness and low conductivity. The practical rule is: rock wool to about 800 °C; ceramic fibre from 800 °C to about 1,300 °C; PCW or layered systems above 1,300 °C. Q: What is the thermal conductivity of calcium silicate insulation board? A: Standard calcium silicate board sits at about 0.045–0.065 W/(m·K) at 400 °C, with a maximum service temperature around 800–1,100 °C. Microporous calcium silicate board, which adds opacifiers to suppress radiation, drops the conductivity to about 0.020–0.035 W/(m·K) — closer to aerogel than to standard calcium silicate. Q: Are refractory ceramic fibers (RCF) dangerous to install? A: RCF and certain older AES grades have been classified by some regulators as substances that warrant careful handling. With modern controls — wet cutting, local exhaust ventilation, suitable respiratory protection, and following the product safety datasheet — installation is routine on industrial sites. Where local rules encourage it, AES or biosoluble fibre grades are available with similar thermal performance and improved clearance behaviour. Q: What is insulating refractory used for in aluminium smelting? A: Aluminium reduction cells operate at around 950–1,000 °C in a cryolite-and-fluoride atmosphere. Microporous calcium silicate board is the textbook insulating refractory here because it combines low thermal conductivity with resistance to fluoride attack, keeping the cell shell temperature low and protecting the surrounding structure. ### Polycrystalline Fiber Modules: Spec, Installation & Applications URL: https://www.rosetexwool.net/news/polycrystalline-fiber-modules-spec-installation-applications/ 2026-09-06 | Author: Rosetexwool Editorial | Category: industry insight Summary: Polycrystalline fiber modules handle 1400–1700 °C service, shrink less than 3 %, and outlast standard ceramic-fiber modules in severe hot-face duty. Polycrystalline fiber modules (often called PCW modules) are the next step up from standard ceramic-fiber modules when furnace temperatures stay above 1400 °C for long periods. They keep the light weight and easy handling of fiber insulation, but their crystal structure — mullite or alpha-alumina rather than glassy aluminosilicate — lets them survive service temperatures that would rapidly shrink or embrittle ordinary modules. This guide explains what makes a polycrystalline mullite fiberboard module different, how the folded and layered designs work, how to install them, and where they earn their place in high-temperature industry. If you are comparing materials first, our article on polycrystalline wool fiber vs standard ceramic fiber breaks down the microstructure gap in more detail. For a wider temperature-rating map, see high-temperature insulation wool temperature ratings and the top 10 high temperature insulation materials hub. What Makes Polycrystalline Fiber Modules Different Standard ceramic-fiber modules are made from glassy aluminosilicate fibers produced by melt spinning. They are excellent up to about 1260 °C, and zirconia-containing grades reach roughly 1430 °C. Above that, the glassy phase begins to crystallize and the fibers become brittle, shrink, and lose their spring-back. Polycrystalline modules are produced by sol-gel and calcination routes, not melt spinning. The result is a fiber made of true crystalline grains: - Polycrystalline mullite modules — Al₂O₃ content around 72–77 %, long-term service up to 1500–1600 °C, short-term peaks to about 1700 °C. - Polycrystalline alumina modules — Al₂O₃ content above 95 %, long-term service up to 1700 °C, short-term peaks to about 1800 °C and occasionally 1900 °C in laboratory conditions. Because the fibers are already crystalline, they do not undergo the rapid devitrification that weakens glassy fibers. Fiber diameters are typically 5–7 µm, slightly coarser than standard 3–5 µm fibers, and the structure is denser and more resistant to hot-gas erosion. The trade-off is higher density and higher raw-material cost, which is why PCW modules are normally reserved for the hot-face layer rather than the entire lining. Temperature, Shrinkage and Thermal Shock Performance The clearest way to compare modules is by what happens when they stay hot. Property | Standard ceramic-fiber module | Polycrystalline module | Long-term service temperature | 900–1260 °C; zirconia grades to 1430 °C | 1400–1700 °C; high-alumina grades to 1750 °C | Short-term peak | ~1500–1600 °C | 1800–1900 °C (short-duration peak only) | Linear shrinkage at rated temperature | ≤2–3 % at 1100–1260 °C | ≤2–3 % at 1500 °C; ≤2.2 % at 1600 °C | Thermal shock resistance | Good; avoid direct flame impingement | Excellent; tolerates direct flame and rapid cycling | Fiber diameter | 3–5 µm | 5–7 µm | Typical density | 160–220 kg/m³ as module | 400–700 kg/m³ as module | Thermal conductivity at 600 °C | ~0.16–0.22 W/(m·K) | ~0.15–0.20 W/(m·K) | The low shrinkage matters more than it first appears. Standard modules hold dimension well at 1000 °C, but at 1400 °C they can lose several percent in length within weeks. That opens joints, creates hot spots, and shortens lining life. PCW modules stay within a few percent shrinkage even after long exposure at 1500–1600 °C, so the lining remains tight and the shell temperature predictable. Service life in severe hot-face service is typically 10 years or more. For board-form products in the same material family, our guide to polycrystalline mullite boards for ultra-high temperature covers the 1600–1900 °C range in more detail. Folded vs Layered Module Construction Fiber modules are not simple blocks of compressed blanket. They are engineered so that the compressed blanket expands after installation, closing gaps and locking the lining together. Folded modules are made by folding a continuous blanket accordion-style into a block. They are larger and heavier than layered modules — a typical 300 mm thick folded module can weigh 10–15 kg — and they carry higher pre-compression. Installers normally handle them from the back, slide them over the anchor studs, and then cut the retaining bands. Expansion after band removal presses neighboring modules against each other. Layered modules are built from stacked blanket layers. They are lighter, easier to cut on site, and more flexible for complex shapes such as curved kiln walls, nozzles, and transition pieces. Their expansion is distributed through the thickness, which can reduce stress at the anchor points. Both designs rely on the same pre-compression principle: the module is held under compression during manufacture and shipping, then allowed to expand in place. A typical pre-compression ratio is 15 % or more. This expansion compensates for the small long-term shrinkage of the fiber and keeps the hot face sealed. Installation patterns are usually either soldier-course (all modules aligned in the same direction) or herringbone/chevron (alternating directions). Chevron layouts give better mechanical interlock and are preferred for roofs, high-velocity flues, and locations with frequent thermal cycling. Anchor Systems and Installation Sequence The anchor system is the hidden half of module performance. Even the best fiber will fail if the anchors overheat, loosen, or are spaced too far apart. Common anchor styles include: - Butterfly / M anchors — embedded in the back of the module, good for flat walls and roofs. - Corrugated or V anchors — grip the folded layers strongly, often used with folded modules. - L-angle anchors — simple and strong, suitable for thicker modules. - Stud-and-retainer pins — used with layered modules or for repair patches. Anchor material must match the service temperature. General guidelines: - Up to 600 °C: 201 or 304 stainless steel. - 600–1100 °C: 304 or 310S stainless steel. - 1100–1400 °C: 310S or higher nickel alloy. - Above 1400 °C: ceramic or high-temperature alloy anchors, because even the best stainless steels lose strength. Anchor spacing is normally 200–250 mm on centers for roofs and 250–300 mm for walls. The anchor head should sit in the cold half of the module, at least 50–75 mm from the hot face, never more than 100 mm. Anchors placed too close to the hot side oxidize, overheat, and can fall out. A typical installation sequence is: - Clean the steel shell and mark anchor locations. - Weld or thread anchors perpendicular to the shell. - Slide modules over the anchors, starting at the roof and working down the walls. - Tighten the module retainer nuts to the specified torque. - Cut the shipping bands and let the modules expand against each other. - Fill gaps over 5 mm with ceramic fiber compensation blanket. - Trim the surface and inspect for loose anchors or open joints. Because PCW modules are heavier than standard modules, two-person handling or light lifting aids are often needed for large folded blocks. The extra weight is the price of the higher density and temperature rating. Where PCW Modules Are Used The applications divide naturally into two groups: places where temperature exceeds what standard modules can take, and places where thermal cycling or flame impingement would destroy a standard lining quickly. Petrochemical cracking furnaces are the classic example. Radiant sections and transfer-line heaters operate with flame temperatures that can spike above 1400 °C and high-velocity flue gases. PCW modules line the radiant walls, roof, and burner openings. Field reports from ethylene-cracker retrofits consistently show major reductions in shell temperature and fuel use — often 15–25 % lower heat loss compared with old refractory-brick linings. Cement and lime rotary kilns use PCW modules at the burner end and in the calcining zone, where gas temperatures and alkali attack are highest. The modules are sometimes backed by ceramic fiber blanket or standard ceramic fiber modules for a stepped insulation system. The lower thermal mass of fiber modules compared with brick also shortens heat-up time and reduces shell stress during shutdown. Metallurgical furnaces — ladle preheaters, soaking pits, reheat furnaces, and non-ferrous melting furnaces — use PCW modules as the hot-face layer. In aluminum melting and holding furnaces, the non-wetting surface treatment prevents molten aluminum from soaking into the fibers. Glass melting furnaces, ceramic tunnel kilns, and incinerators also use PCW modules where flame impingement, rapid cycling, or high oxygen demand rules out standard fiber. In a tunnel-kiln retrofit, replacing a dense brick lining with fiber modules can cut the lining weight by up to 90 % and reduce heat-up/cool-down time by 30–50 %. Specification and Selection Table Use the table below as a starting point for discussions with your supplier. Exact values depend on density, fiber grade, and surface treatment. Grade | Long-term limit | Density (kg/m³) | Shrinkage (24 h at test temp) | Typical λ at 600 °C | Best suited for | Standard ceramic-fiber module | 1050–1260 °C | 160–220 | ≤2 % at 1100 °C | 0.16–0.22 W/(m·K) | General furnace walls, kilns, boilers | Zirconia-enhanced ceramic-fiber module | up to 1430 °C | 180–240 | ≤2 % at 1260 °C | 0.16–0.20 W/(m·K) | Higher-temperature kilns, non-ferrous melting | Polycrystalline mullite module | 1500–1600 °C | 400–600 | ≤3 % at 1500 °C | 0.15–0.19 W/(m·K) | Cracker radiant walls, kiln hot zone, incinerators | High-alumina polycrystalline module | 1650–1750 °C | 450–700 | ≤2.2 % at 1600 °C | 0.17–0.20 W/(m·K) | Extreme hot face, glass furnaces, special kilns | Note that the high-alumina grade’s short-term peak can reach about 1800 °C, and even 1900 °C in controlled laboratory exposure. Do not design continuous operation at those peak values; use them only to cover brief excursions such as start-up, flame impingement, or emergency overheating. How to Select the Right Module Choosing between standard, zirconia-enhanced, and polycrystalline modules comes down to four questions: - What is the normal operating temperature? If the hot face stays below 1200 °C, standard modules are usually the economical choice. Between 1200 °C and 1450 °C, zirconia-enhanced modules bridge the gap. Above 1450 °C, move to polycrystalline. - What is the peak temperature and duration? A 1350 °C peak for a few minutes is different from 1350 °C continuous. PCW modules tolerate short peaks far above their continuous rating. - Is there direct flame or high gas velocity? Flame impingement and high-velocity flue gases erode standard fibers. PCW modules, with their coarser crystalline fibers and higher density, last much longer. - What is the required lining life? If the furnace campaign must run 8–10 years or longer without reline, the higher first cost of PCW modules is usually recovered by avoiding a mid-campaign shutdown. For the backing layer behind PCW modules, use lower-density ceramic fiber or vacuum-formed boards. The PCW module carries the hot-face duty, while the backup layer provides thermal resistance at a lower cost. Conclusion Polycrystalline fiber modules are not simply hotter versions of standard ceramic-fiber modules. They are a different class of material, built from crystalline oxide fibers that resist shrinkage, thermal shock, and hot-gas erosion at temperatures where glassy fibers fail. Their folded or layered construction, combined with proper anchoring and expansion compensation, creates a lining that stays in place for many years. The decision to use them should be based on real operating conditions: continuous temperature, peak temperature, flame contact, gas velocity, and required campaign life. Where those conditions justify the investment, PCW modules outperform standard modules by a wide margin. When continuous temperature exceeds the PCW module range, the next tier is alumina zirconia ultra-high-temperature fiber. For the companion application guide that maps alumina and AES to furnace zones, see ceramic fiber module applications in alumina/AES linings. Specify the density, fiber grade, and anchor material carefully, and the lining will deliver the long service life and stable shell temperatures that high-temperature plants need. For supplier qualification and a buyer's checklist, see our polycrystalline fiber module supplier guide. Related products: Calcium Silicate Insulation Board Related applications: Cement FAQ: Q: What is a polycrystalline fiber module? A: A polycrystalline fiber module, or PCW module, is a pre-formed insulation block made from crystalline mullite or alumina fibers. It is designed for long-term service at 1400–1700 °C, well above the limit of standard glassy ceramic-fiber modules. Q: How does a PCW module differ from a standard ceramic-fiber module? A: PCW modules use crystalline fibers with higher Al₂O₃ content, so they resist shrinkage, thermal shock, and high-velocity hot gas better. They are denser (400–700 kg/m³), last longer at temperature, and can withstand short-term peaks to 1800–1900 °C. Q: What is the maximum temperature for polycrystalline fiber modules? A: Polycrystalline mullite modules are typically rated for 1500–1600 °C continuous service. High-alumina grades reach 1650–1750 °C, with short-term peaks to about 1800 °C and laboratory peaks near 1900 °C. Do not use the peak value for continuous design. Q: What does folded vs layered module construction mean? A: Folded modules are made by folding a continuous blanket accordion-style; they are larger and stiffer. Layered modules are built from stacked blanket layers; they are lighter and easier to shape around curves and nozzles. Both rely on pre-compression to seal joints after installation. Q: How are polycrystalline fiber modules anchored? A: They are held by stainless-steel or high-temperature alloy anchors embedded in the cold half of the module. Common styles include butterfly, V, L-angle, and stud-and-retainer anchors. At temperatures above 1400 °C, ceramic anchors are preferred. Q: What anchor spacing should be used? A: Typical center-to-center spacing is 200–250 mm for roofs and 250–300 mm for walls. Anchors should be at least 50–75 mm from the hot face, never more than 100 mm, to avoid overheating. Q: Where are PCW modules most commonly used? A: They are used in petrochemical cracking furnaces, cement and lime rotary kilns, metallurgical furnaces, glass melting furnaces, ceramic tunnel kilns, and incinerators — anywhere the hot face exceeds 1400 °C or suffers flame impingement and rapid cycling. Q: What shrinkage can be expected from PCW modules? A: Polycrystalline mullite modules typically show ≤3 % linear shrinkage after 24 hours at 1500 °C. High-alumina grades show ≤2.2 % at 1600 °C. These values are much lower than standard modules at equivalent temperatures. Q: Can PCW modules be used directly against molten aluminum? A: They can be used as the hot-face lining in aluminum melting and holding furnaces when supplied with a non-wetting surface treatment. The treatment prevents molten aluminum from penetrating the fibers. Q: How do I choose between PCW and standard ceramic-fiber modules? A: Use standard modules for continuous temperatures below 1200 °C, zirconia-enhanced modules for 1200–1450 °C, and polycrystalline modules above 1450 °C or where there is direct flame, high gas velocity, or a required campaign life of 8–10 years or more. ### Marine Insulation Materials: Thermal & Acoustic Specifications for Ships & Offshore URL: https://www.rosetexwool.net/news/marine-insulation-thermal-acoustic-specifications/ 2026-09-04 | Author: Rosetexwool Editorial | Category: industry insight Summary: Non-fire marine insulation guide — engine-room & accommodation thickness, condensation control, NRC acoustic, HVAC/cold-room sizing, LNG tiers, IMO/CCS limits. Scope of This Guide Marine and offshore insulation is usually described through its fire-protection role — SOLAS A-class divisions, FTP Code, hydrocarbon curves. That is the largest single chapter, but it is not the only one. This guide covers the equally important non-fire performance of marine insulation: controlling heat loss and surface condensation in engine rooms and accommodation, meeting cabin acoustic targets, sizing HVAC ducts and cold rooms, and specifying materials for LNG low-temperature zones that are below −100 °C and have nothing to do with flammability. Salt-spray corrosion and shipboard vibration durability are included as system-level selection criteria. If you need the fire-rated side (A-60, H-120, class-approval), see our marine fire insulation materials and standards guide and the A-60 marine insulation thickness guide. The material-selection basics for the most common shipboard product — rock wool — are in rock wool marine and offshore applications. Engine Room and Accommodation Pipe Insulation Thickness The two governing variables are operating temperature and ambient conditions. On a ship, the ambient envelope swings from a refrigerated cargo hold to a tropical engine room, often on the same voyage. The table below gives typical first-pass thickness (mm) for clean bare steel pipe at an ambient of about 30 °C, suitable for non-fire zones inside the engine room and accommodation. Operating Temp | Rock Wool (mm) | Glass Wool (mm) | Calcium Silicate (mm) | PU Foam (mm) | 100 °C | 25–30 | 20–25 | 15–20 | 15–20 | 150 °C | 35–40 | 30–35 | 25–30 | 20–25 | 200 °C | 45–50 | 40–45 | 35–40 | 25–30 | 250 °C | 55–60 | 50–55 | 45–50 | 30–35 | 300 °C | 65–70 | 60–65 | 55–60 | 35–40 | Three rules fall out of the table: - Thickness rises roughly linearly with temperature. Every 100 °C step adds about 10 mm for the same pipe at this ambient. - Glass wool is consistently 5–10 mm thinner than rock wool at the same temperature because its conductivity at low mean temperature is slightly lower. - PU foam is the thinnest option for moderate service but should not be used above about 110 °C continuous — it is included here for completeness on chilled-water and HVAC lines, not for engine exhaust. For accommodation cabins the table is usually dialled back to about 80–90 % of the engine-room thickness, balancing heat-loss control with the cabin's own internal heat gains and limited wall depth. On low-temperature cabins the thickness goes the other way — it must be increased to prevent surface condensation. That is the next section. For the underlying material data and conductivity curves used to build this table, see our industrial pipe insulation types guide and the pipe insulation materials page. Condensation Control: Calculation and Worked Example Surface condensation is the most common non-fire failure mode in marine insulation. A cold pipe in a humid cabin sweats, the water pools, corrodes the steel, and drips onto electrical equipment. The cure is a calculation, not a thicker blanket. The condensation-control formula: δ = λ × (Ts − Tf) / (αs × (Ta − Td)) where: - δ = insulation thickness (mm) - λ = thermal conductivity of the insulation (W/m·K) - Ts = required outside-surface temperature (°C); set to Td + 0.3 °C to keep a small safety margin - Tf = process / pipe-wall temperature (°C) - αs = surface heat-transfer coefficient; for still indoor marine air, use about 8.14 W/m²·K - Ta = ambient air temperature (°C) - Td = dew-point temperature (°C), from a psychrometric table for the local (T, RH) Worked example — HVAC duct in a tropical engine room. - Air inside duct: 18 °C - Ambient: 35 °C at 80 % relative humidity - Dew point Td: 28.5 °C - Required surface temperature Ts: 28.5 + 0.3 = 28.8 °C - Insulation: glass wool, λ = 0.040 W/m·K - Diameter: 200 mm (the calculation is per unit area, so size drops out) δ = 0.040 × (28.8 − 18) / (8.14 × (35 − 28.5)) = 0.040 × 10.8 / 52.9 ≈ 8.2 mm For shipboard service add a 15 % safety margin for material aging, salt-spray absorption and seam gaps, giving a design thickness of about 10 mm. Round up to the next available product gauge. This matches the HVAC duct table in the next section. Three correction factors ship designers apply on top of the formula: - Humidity correction — for outdoor decks and high-humidity spaces, add 10–15 % to the calculated thickness. - Wind correction — on open decks the αs value rises sharply with wind speed; use a higher αs and re-derive δ. - Material aging — over a 15–20 year service life, fibrous insulation can absorb 1–3 % moisture by weight, which raises its effective λ. The safety margin covers this. Cabin and Accommodation Acoustic Performance Marine insulation is also the acoustic absorber in most accommodation modules. The metric is the Noise Reduction Coefficient (NRC) — the average absorption at 250, 500, 1000 and 2000 Hz. Typical marine targets: Space | NRC Target | Practical Material | Accommodation cabins | ≥ 0.6 | Glass wool 40–60 kg/m³, 40 mm | Crew mess and corridors | ≥ 0.5 | Glass wool 32–48 kg/m³, 30–40 mm | Engine control room | ≥ 0.4 | Rock wool 40–60 kg/m³, 30–40 mm | Cargo hold | ≥ 0.3 | Mineral wool 24–40 kg/m³, 25–30 mm | A representative composite wall build-up for an accommodation cabin: - Epoxy primer (≈ 50 µm, anti-corrosion) - Glass wool acoustic-thermal layer, 48 kg/m³, 40 mm - Polyurethane damping layer, 10 mm (to break the structure-borne path) - Aluminium vapour barrier, 0.5 mm - Decorative acoustic panel, 5 mm That stack typically delivers NRC ≈ 0.7 and an airborne sound insulation of ≥ 35 dB between 100 and 4000 Hz — the usual spec for a passenger or high-end accommodation cabin. For the acoustic product side, see our rock wool acoustic panels and the glass wool board product page. HVAC Duct and Cold-Room Insulation Marine HVAC and refrigeration lines are the highest-volume insulation application on most vessels. The two design drivers are heat-loss / heat-gain and anti-condensation, and they usually lead to the same thickness number. Typical HVAC duct insulation thickness (chilled air at 7–18 °C, ambient 35 °C, glass wool λ ≈ 0.040 W/m·K): Duct Diameter (mm) | Air 18 °C — Glass Wool (mm) | Air 7 °C — Glass Wool (mm) | 100 | 10 | 20 | 150 | 12 | 25 | 200 | 15 | 30 | 250 | 18 | 35 | 300 | 20 | 40 | For rock wool add 2–3 mm; for PU foam subtract 2–3 mm at the same diameter. Cold rooms go further. Two product families dominate: - PU / PIR foam — λ ≈ 0.022–0.028 W/m·K, closed cell, water uptake < 1 %. The default choice for provision stores at +5 °C down to about −30 °C. - Silica aerogel blanket — λ ≈ 0.018–0.024 W/m·K. Used where the wall cavity is fixed and every millimetre matters, such as reefer container conversions. For very low temperature service (−40 °C and below) PU thickness pushes past 100 mm, at which point designers either accept the wall build-up or switch to a vacuum insulation panel (VIP) with λ ≈ 0.007–0.010 W/m·K. VIPs are excellent thermally but expensive and difficult to replace, so they are usually limited to localised hot spots on an otherwise foam-lined room. For the cryogenic side below −100 °C, the next section applies. LNG Low-Temperature Zones (Non-Fire) LNG carriers and LNG-fuelled vessels carry cargo or bunker tanks at about −162 °C. This is outside the range of conventional pipe insulation and well outside the range of fire-rated marine insulation. Three material families do the bulk of the work: Family | λ (W/m·K) | Service Temp | Typical Thickness | Reinforced PU foam | 0.022–0.028 | −162 °C to +40 °C | 200–250 mm (membrane tank), 450 mm (B-type) | LNG elastic felt (needled glass) | 0.018–0.023 | down to −180 °C | 30–50 mm (pipe fittings) | Low-temperature rock wool / glass wool | 0.022–0.035 | down to −100 °C | 50–80 mm (secondary barrier) | Silica aerogel blanket | 0.018–0.024 | down to −200 °C | 20–40 mm (space-limited) | Vacuum insulation panel (VIP) | 0.007–0.010 | −196 °C to −100 °C | 20–40 mm (space-limited) | Perlite (expanded) | bulk fill | −196 °C to ambient | full secondary barrier fill | Thickness logic: - Membrane containment systems (GTT NO96, Mark III) — about 200–250 mm of PU foam as the primary insulation, often with a perlite or foam-glass secondary barrier. - Independent B-type containment — about 450 mm of PU foam, sized to keep the boil-off rate (BOR) below 0.10 % per day. - Main cargo piping — 50–80 mm PU foam, sometimes with an outer rubber or GRP jacket. - Bends, valves and fittings — 30–50 mm LNG elastic felt, which tolerates thermal contraction without cracking. For vessel-level LNG insulation design, the relevant rule is the IGC Code (IMO) and class society rules (DNV, LR, BV, CCS). This is a different document set from SOLAS Chapter II-2 fire protection. The cryogenic pipe-insulation system for the rest of the plant (not LNG cargo) is covered in our cryogenic pipe insulation guide. IMO and Class-Society Physical-Property Limits (Non-Fire) IMO does not write a single “non-fire marine insulation” standard. Instead, the FTP Code, the IGC Code and the individual class-society rules (DNV, LR, CCS, BV) place indirect physical-property limits on every insulation material that goes on a ship. In practice this collapses to four numbers a buyer should check on the datasheet: Property | Conventional Service | Low-Temp Service | Cryogenic Service | Thermal conductivity λ | ≤ 0.064 W/m·K | ≤ 0.030 W/m·K | ≤ 0.018 W/m·K | Density | 32–80 kg/m³ (±5 %) | 32–80 kg/m³ (±5 %) | 32–80 kg/m³ (±5 %) | Compressive strength | ≥ 15 kPa (general), ≥ 30 kPa (structural) | ≥ 30 kPa | ≥ 50 kPa | Water absorption | ≤ 1 % by volume (with vapour barrier on fibrous types) | ≤ 1 % | ≤ 0.5 % | Adhesives, facings and jacketing are checked separately. A pull-off test of ≥ 50 kPa on the bond to the substrate is the usual minimum, plus a thermal-cycle test (typically 10 cycles between ambient and the design low temperature) with no delamination. For non-fire zones inside accommodation the adhesive also has to meet the IMO FTP Code low-spread-of-flame criteria, even when the insulation itself is not classed as a fire division. Salt-Spray and Vibration Durability A ship is a corrosive, vibrating environment. Two accelerated tests are used to qualify insulation materials for marine service: Salt-spray test (per DNV-CG-0339 and equivalent class-society guidance) - Conditions: 5 % NaCl solution, 35 °C, 95 % RH - Duration: 3000 h standard, up to 5000 h for harsh service - Pass criteria: strength loss ≤ 15 %, mass loss ≤ 10 %, no visible pitting on the metal jacket Vibration test (per CCS materials & welding code and equivalent) - Frequency sweep: 5–30 Hz - Acceleration: 0.05–0.10 g - Cycles: ≥ 10 000 - Pass criteria: fibre shed ≤ 5 %, tensile-strength retention ≥ 90 %, thickness change ≤ 3 % A material that passes both tests is qualified for unrestricted marine service. Fibrous materials (rock wool, glass wool) generally need a vapour barrier and metal jacket to keep salt-laden air out; closed-cell foams and aerogel blankets are hydrophobic enough to pass without an extra barrier, but are still jacketed for mechanical protection on weather-exposed decks. Quick Selection Matrix Zone | Default Material | Typical Thickness | Engine-room pipes (≤ 300 °C) | Rock wool or glass wool with metal jacket | 25–70 mm by temperature | Accommodation thermal | Glass wool 32–48 kg/m³ + acoustic panel | 30–50 mm | Accommodation acoustic | Glass wool 40–60 kg/m³, NRC ≥ 0.6 | 40 mm | HVAC ducts (chilled) | Glass wool with aluminium vapour barrier | 10–40 mm by diameter | Cold rooms (≥ −30 °C) | PU / PIR foam, closed cell | 80–120 mm | Cold rooms (< −30 °C) | PU foam or aerogel blanket | 100–200 mm | LNG cargo (primary) | Reinforced PU foam | 200–450 mm | LNG pipes / fittings | LNG elastic felt | 30–50 mm | Open deck (any service) | Fibrous insulation + metal jacket, qualified to DNV-CG-0339 | project-specific | For the product side, our rock wool blanket, rock wool board, glass wool board and nano aerogel insulation blanket cover the four most-used marine materials; the marine & offshore application page maps them to specific shipboard zones. All materials are produced under ISO 9001 quality management and are supported by EN 13501-1 / IMO FTP Code test data on request. Related products: Calcium Silicate Pipe, Ceramic Fiber Plus Blanket Related applications: Marine & Offshore FAQ: Q: What is the typical pipe insulation thickness for a marine engine room? A: For clean bare steel pipe at 30 °C ambient, plan on 25–30 mm of rock wool or glass wool at 100 °C, scaling up to 65–70 mm at 300 °C. Calcium silicate is 5–10 mm thinner at the same temperature; PU foam is thinnest but is limited to about 110 °C continuous service. Q: How do I calculate insulation thickness to prevent condensation on a marine pipe? A: Use the formula δ = λ × (Ts − Tf) / (αs × (Ta − Td)), with Ts set to dew point Td + 0.3 °C and αs about 8.14 W/m²·K for still indoor air. For outdoor decks, raise αs for wind, and add a 10–15 % safety margin for material aging and salt-spray absorption. A worked HVAC example lands at about 10 mm of glass wool for an 18 °C duct in 35 °C / 80 % RH ambient. Q: What NRC value is required for shipboard cabins? A: Accommodation cabins usually need NRC ≥ 0.6, crew mess and corridors ≥ 0.5, the engine control room ≥ 0.4, and cargo holds ≥ 0.3. A 40 mm glass-wool layer at 48 kg/m³ behind a perforated acoustic panel is the typical way to clear the cabin target. Q: Which insulation material is used in LNG cargo tanks? A: Reinforced PU foam at 200–250 mm for membrane containment systems (NO96, Mark III) and about 450 mm for independent B-type tanks. LNG pipes and fittings use LNG elastic felt at 30–50 mm to handle thermal contraction without cracking. Q: Do IMO rules specify insulation thickness for non-fire zones? A: No single IMO rule fixes a non-fire thickness. Instead, the FTP Code, the IGC Code and class-society rules (DNV, LR, BV, CCS) place indirect physical-property limits — λ ≤ 0.064 W/m·K for conventional service, ≤ 0.030 W/m·K for low-temperature service, ≤ 0.018 W/m·K for cryogenic service — plus density, compressive strength and water-absorption limits. Thickness is then derived from the heat-loss or condensation calculation for the specific zone. Q: What salt-spray test does marine insulation need to pass? A: Per DNV-CG-0339 and equivalent class-society guidance, 5 % NaCl at 35 °C and 95 % RH for 3000 h standard (extendable to 5000 h). Pass criteria are strength loss ≤ 15 %, mass loss ≤ 10 % and no visible pitting on the metal jacket. Q: What vibration test does marine insulation need to pass? A: Per the CCS materials and welding code and equivalent rules, a 5–30 Hz sweep at 0.05–0.10 g for at least 10 000 cycles. Pass criteria are fibre shed ≤ 5 %, tensile-strength retention ≥ 90 % and thickness change ≤ 3 %. Q: Can I use the same insulation in accommodation and on deck? A: You can use the same material, but the build-up changes. Indoor accommodation only needs a vapour barrier and a decorative acoustic panel. On open deck you need a full metal jacket (galvanised steel or aluminium), sealed seams facing down, and the system must be qualified to the salt-spray and vibration tests above. Q: How thick should PU foam be for a marine cold room? A: For a provision store at +5 °C, 80–100 mm of PU / PIR foam is typical. For a reefer room at −30 °C, plan 120–150 mm. Below −40 °C the thickness pushes past 200 mm; in space-limited locations a hybrid build with silica aerogel or vacuum insulation panels is common. Q: Where does aerogel blanket earn its cost on a ship? A: Where the wall cavity is fixed and every millimetre of build-up matters — for example, retrofit acoustic-thermal upgrades inside existing accommodation, or localised hot spots on LNG piping where the conventional foam would be too thick. In open engine rooms the cost is rarely justified. ### Glass Wool Acoustic Insulation: NRC & Application Guide URL: https://www.rosetexwool.net/news/glass-wool-acoustic-insulation/ 2026-09-04 | Author: Rosetexwool Editorial | Category: industry insight Summary: Glass wool acoustic insulation: NRC and αw by density and thickness, mass-spring-mass wall and ceiling constructions, machine-room enclosures, and rock wool acoustic panels compared. Glass wool acoustic insulation is one of the few building materials that simultaneously does two opposite jobs — it absorbs sound and it muffles heat loss — and most of the specification work is getting those two jobs to talk to each other rather than fight. This guide collects the noise-reduction coefficient (NRC) and weighted absorption coefficient (αw) data that actually controls an acoustic bid, the four application constructions that show up in 90% of projects (partition wall, ceiling lining, machine-room enclosure, duct lagging), the points where glass wool gives up and rock wool acoustic panels take over, and the parameter list every acoustic report needs before a project clears review. For the material's thermal properties outside the acoustic context, see our industrial pipe insulation materials hub and the glass wool board applications page — this article stays strictly inside the acoustic frame. What NRC and αw actually tell you Most procurement teams reach for NRC first because it is the only number on the data sheet that combines the four speech-band frequencies (250, 500, 1000 and 2000 Hz) into a single figure. The arithmetic mean is rounded to the nearest 0.05. The range you will see on a glass wool line card is roughly 0.70 to 1.00, but the practical values cluster as follows: Configuration | NRC | αw | Test standard | 50 mm, 24 kg/m³ | 0.85 | 0.75 | ASTM C423 / ISO 354 | 50 mm, 48 kg/m³ | 0.95 | 0.90 | ASTM C423 / ISO 354 | 100 mm, 48 kg/m³ + 100 mm cavity | 1.00 | 0.95 | ASTM C423 / ISO 354 | 25 mm, 32 kg/m³ (direct-mount) | 0.60 | 0.55 | ASTM C423 / ISO 354 | The numbers hide three traps. First, NRC is speech-band only — it says nothing about low-frequency rumble (50–125 Hz), which is exactly where HVAC noise and traffic noise live. Second, αw is the figure you use for international certification (ISO 11654 / EN ISO 11654) because it weights the absorption curve by human-ear sensitivity; a 0.05 difference in αw can swing a project onto the design-corrective-action list. Third, what the suppliers print on a brochure and what a third-party reverberation-room test shows can differ by 0.10 — always ask for the test report, not the brochure. How glass wool absorbs and isolates sound The absorption mechanism is the part that surprises people coming from thermal insulation: it has nothing to do with density per se and everything to do with air friction in micro-channels. Glass fibres typically 5–8 µm in diameter pack into a felt that is 95% air by volume. When a sound wave enters the felt, the air molecules next to each fibre vibrate against the fibre wall, and viscous drag converts that motion into heat. The absorption coefficient therefore rises steeply with thickness (more air column to friction against) and only mildly with density (more fibres per cm³ to friction against), until density crosses about 120 kg/m³ — beyond which the felt becomes acoustically reflective and absorption drops. The isolation mechanism (Rw, sound transmission loss) is a different story. A glass wool batt alone is a terrible sound barrier — at 50 mm and 48 kg/m³ it reaches maybe 18 dB Rw, which is irrelevant next to a 9 dB drop from a single electrical outlet. Real isolation comes from composite systems built on the mass–spring–mass principle: - Mass layer 1 — high surface density (12 mm gypsum ≈ 10 kg/m² ≈ 30 dB by mass law) - Spring layer — air cavity 50–100 mm deep, sometimes with damping material - Mass layer 2 — second gypsum or steel sheet - Absorption cavity fill — glass wool, packed to about 45 kg/m³ to break the cavity resonance without choking the air spring Two 12 mm gypsum boards bracketing a 50 mm glass wool cavity at 48 kg/m³ reach a laboratory STC in the 50–58 dB range. Add a 3 mm butyl-rubber damping sheet between one gypsum face and the studs and the same build can climb to 58–63 dB — a noticeable step change for the marginal cost of one damping sheet. For the broader composite-wall story including the dual-layer layouts that pair glass wool with rock wool acoustic panels, see our rock wool acoustic panels page, which covers the higher-density half of the product range. Partition wall construction The reference partition for residential and office work looks like this, from one face to the other: Face A — 12 mm gypsum board Studs — light-gauge steel C 50 × 30 × 0.6 mm, 400 mm centres, on 5 mm EPDM isolators (decoupled from structure) Cavity — 50 mm glass wool, 48 kg/m³, friction-fit between studs Damping — 3 mm butyl-rubber mass-loaded vinyl (optional) Face B — 12 mm gypsum board Total wall thickness: 130–150 mm. Rw 50–58 dB in lab test (35–45 dB in the field, after electrical outlets and services). The four installation points that decide whether the wall hits the rated value or underperforms by 8–10 dB are: - Stud isolation — studs must NOT touch the surrounding structure. An EPDM strip under the bottom track and a continuous bead of sealant at the head is non-negotiable. - Batt continuity — joints staggered at least 50 mm. Any gap wider than about 5 mm at a panel joint drops the field rating by roughly 10 dB. - Service penetrations — switch boxes back-to-back on the same stud bay are the single most common failure. Offset them by at least one stud cavity. - Damping sheet continuity — if used, the sheet must wrap the perimeter of the partition, not stop short at the corners. The batt at 48 kg/m³ is an acoustic choice, not a thermal one — at lower densities you get the same Rw with thicker material, which trades stud depth for dollars. The glass wool batt for these partitions is supplied in rolls cut to fit a 600 mm stud bay; for the material range see our glass wool blanket product page. For heavyweight venues (recording studios, dubbing rooms, music practice rooms) the same system steps up to 15 mm gypsum both faces, 0.8 mm steel studs at 300 mm centres, 100 mm glass wool at 60 kg/m³, 5 mm damping sheet, and pulls Rw 58–65 dB. Ceiling lining construction Ceiling acoustics usually work against thermal insulation rather than with it: the question is how much sound absorption you can stack over a roof slab without losing the thermal R-value. The reference layering for office and conference-room builds: - 12 mm gypsum board (the finished face) - 50 mm glass wool at 32 kg/m³, with a 50 mm air gap above it - 100 mm thermal glass wool at 24 kg/m³, adhered to the slab soffit The split is intentional: the lower-density felt absorbs (mid–high speech band), the higher-density layer above adds the thermal break. Combined absorption rating sits around NRC 0.85 and αw 0.75 at 100 mm total build. For cinema and auditorium work the layering gets a damping sheet and the construction rises to 100 mm glass wool at 48 kg/m³ in a 100 mm cavity, with NRC above 0.95 and αw 0.90. The construction should be hung on decoupled hangers (spring or rubber-in-shear type, 60–80 cm grid), and any lighting or sprinkler penetrations through the lining must be sealed with non-setting acoustic sealant — a single unsealed down-light can leak 4–6 dB. Machine-room acoustic enclosures Acoustic enclosures around pumps, compressors, gensets and chillers are the place where glass wool earns its keep most decisively, because the noise source has a defined spectrum and a defined surface area. The reference enclosure, for a unit operating at 85–95 dB(A) free-field: Outer skin — 2–3 mm galvanised steel sheet Damping — 2 mm bitumen-based damping mat (loss factor ≥ 0.3) Cavity — 60–100 mm air gap Inner fill — 50 mm glass wool, 48 kg/m³, behind 0.8 mm perforated galvanised steel (perforation 20–30%, hole Φ3 mm) Inner face — perforated steel skin (sound enters, is absorbed, cannot reflect back into the cavity) Insertion loss target — 35–45 dB(A) Three rules determine whether the enclosure meets the rated insertion loss (IL) or merely looks like it does. The leakage area (gaps around doors, pipe penetrations, cable glands) must stay below 10% of the total enclosure surface area; for every doubling of leakage area the IL drops by roughly 3 dB. Every duct into the enclosure needs a flexible connector and an acoustic splitter silencer rated at 25 dB(A) or better. The door should be a double-seal acoustic door with cam-lift hinges — a standard industrial door is the second-largest leak after the ventilation path. For high-temperature enclosures (boiler rooms, exhaust manifolds, furnace plenums) the glass wool has to be the foil-faced high-density variant (80 kg/m³, 80 mm) and the damping mat upgraded to a high-temperature grade rated to at least 500 °C. Rated IL drops to 30 dB(A) but the working life inside the rated temperature window rises to the same 40-year envelope as the industrial insulation stack. Where glass wool's 400 °C ceiling is the binding limit, the enclosure can either step up to a rock wool acoustic panel inner skin or carry a separate thermal barrier outside the acoustic layer. Glass wool vs rock wool acoustic panels When the question moves from "what absorbs" to "what survives", glass wool and rock wool acoustic panels start to diverge: Property | Glass wool | Rock wool acoustic panel | Thermal conductivity (W/(m·K)) | 0.035–0.040 | 0.040–0.045 | Continuous service temperature | ≤ 400 °C | ≤ 700 °C | Fire classification (EN 13501-1) | A1 non-combustible | A1 non-combustible | Mid–high frequency α (500–2000 Hz) | 0.80–0.95 | 0.70–0.85 | Low-frequency α (125 Hz, 50 mm) | 0.20–0.40 | 0.30–0.45 | Hydrophobicity | ≥ 98 % | ≤ 80 % | Chemical stability | pH 7–8, neutral | Slightly alkaline; can corrode unprotected steel | Density range for acoustic use | 24–100 kg/m³ | 40–200 kg/m³ | Cost per acoustic-Rw unit | Lower | 30–60 % higher | The rule of thumb that holds across most projects: glass wool for indoor conditioned space where mid–high frequency absorption is the goal; rock wool where continuous surface temperature exceeds 250 °C, where hydrocarbon or solvent exposure is a possibility, or where mechanical robustness is critical (industrial walls, mechanical-room soffits, plant rooms). The two materials can be combined in a single build — a thin low-density glass wool layer for absorption plus a higher-density rock wool facing for impact and fire — but every combined layer adds labour and the design must show why the combination is worth doing. Acoustics is one of seven decision axes; temperature, fire, density and cost are the others, set out in our glass wool vs rock wool comparison across all six forms. Acoustic-report parameter checklist An acoustic report that gets accepted by a reviewer on the first pass covers five blocks. Skip one and the report goes back for revision: - Material identity — type (glass wool), form (board / blanket / loose fill), density (kg/m³), thickness (mm), fibre diameter (µm), facing (none / foil / glass cloth / VIP), fire classification (EN 13501-1 letter and year), hydrophobicity rating if in service. - Acoustic data — six-band α values at 125, 250, 500, 1000, 2000, 4000 Hz; NRC rounded to 0.05; αw with shape indicator; Rw for any composite system tested as a unit (not for the glass wool alone). - Installation conditions — stud or joist depth and spacing, cavity depth, presence of damping sheet, mounting method (direct / spaced / suspended), any deviation from the tested configuration. - Test provenance — reverberation-room volume (≥ 200 m³ per ISO 354), third-party lab accreditation, date of test, test report number that can be cross-referenced. - Scope of validity — frequency band over which the data is reliable, conditions under which the rating is invalidated (humidity above 70 %, surface temperature outside the rated window, mechanical loading beyond design), and the limit of applicability to similar but not identical builds. For moisture-exposed service, the hydrophobicity rating needs to be > 98 %; the glass wool blanket waterproofing page sets out the testing protocol. For purely thermal context where acoustic is secondary, the glass wool board applications page covers the construction-trade reading. Where glass wool acoustic insulation is the wrong answer Three situations trip up the unwary. Low-frequency-only sources (transformer hum, large compressor pulsation) need a thick cavity and tuned damping — glass wool alone at 50 mm cannot bring a 63 Hz tone below the design threshold. Outdoor service without a vapour-tight facing is a maintenance trap; even at 98 % hydrophobicity, the long-term water-vapour transmission rate will degrade αw by 0.10 over a five-year cycle. Plenum return air in HVAC systems has strict surface-speed limits (around 3–5 m/s for glass wool faced with a glass cloth, lower for unprotected felt) — above those limits fibres shed and the supply stream becomes the indoor air-quality problem. In each of those cases, the engineering fix is not "more glass wool" but a different acoustic strategy: tuned-mass dampers for low frequency, foil-faced hydrophobic batts for outdoor service, and high-density rigid boards for plenum return. The right move is to identify these at specification stage rather than discover them in the post-installation acoustic test. Glass wool acoustic insulation stays the right answer in roughly 80% of indoor commercial builds; the work is choosing the density and thickness that actually reaches the rated NRC and verifying with a third-party test report rather than a brochure number. Quick specification summary A starting configuration that resolves most indoor commercial acoustic bids without further iteration: - Partition wall: 50 mm glass wool at 48 kg/m³ between 50 mm light-gauge steel studs on EPDM isolators, finished both faces with 12 mm gypsum → Rw 50–58 dB. - Ceiling lining: 50 mm glass wool at 32 kg/m³ in a 50 mm air cavity, under 12 mm gypsum → NRC 0.85, αw 0.75. - Machine-room enclosure: 50 mm glass wool at 48 kg/m³ inside a 60–100 mm cavity, behind 0.8 mm perforated steel with 20–30 % open area, plus 2 mm damping mat and 2–3 mm outer steel skin → IL 35–45 dB(A). - Step up to rock wool acoustic panels: surface temperature > 250 °C, hydrocarbon exposure, or mechanical impact is foreseeable. - Always request from supplier: third-party ASTM C423 / ISO 354 test report with six-band α data, NRC rounded to 0.05, and αw with shape indicator. Anything outside that envelope — large low-frequency tones, outdoor service, plenum return air, or a project-specific fire classification — needs its own design pass before the bid locks in. Related products: Glass Wool Board, Glass Wool Blanket Related applications: Building, Green Building & Retrofit FAQ: Q: What NRC should I specify for a glass wool acoustic ceiling? A: For office and conference work the target is NRC ≥ 0.85 with αw ≥ 0.75; for cinemas, auditoria and recording studios it rises to NRC ≥ 0.95 with αw ≥ 0.90. Both are reached at 50 mm and 48 kg/m³, or at 100 mm with a 50 mm cavity behind a perforated facing. Q: Can glass wool replace rock wool acoustic panels in a partition wall? A: Yes, when the surface temperature stays below 250 °C and there is no hydrocarbon exposure; in those conditions glass wool at 48 kg/m³ matches or slightly exceeds rock wool for mid–high frequency absorption. At higher temperatures or where mechanical robustness matters, rock wool remains the better choice. Q: Does 100 mm glass wool beat 50 mm glass wool for soundproofing? A: Doubling thickness from 50 mm to 100 mm typically gains 4–6 dB of Rw in a composite system and shifts the low-frequency absorption edge down by roughly an octave. The exact gain depends on whether the cavity is still air-filled or damped; in a tuned build the difference can be larger. Q: What does αw mean and how is it different from NRC? A: NRC is the arithmetic mean of four speech-band absorption coefficients, reported to 0.05. αw is the weighted sound-absorption coefficient that follows ISO 11654 / EN ISO 11654 and reflects human-ear sensitivity across the spectrum. A material with NRC 0.90 can have αw anywhere from 0.70 to 0.95 depending on the absorption curve shape. Q: How does humidity affect glass wool acoustic performance? A: Above 70 % relative humidity, NRC typically falls by 8 to 12 % because water vapour displaces the air in the felt and changes the viscous damping. For high-humidity service, specify glass wool with a hydrophobicity rating of at least 98 % and a facing that breaks the moisture path. Q: What density of glass wool is best for a partition wall? A: 48 kg/m³ is the working density for most partition walls. Below 32 kg/m³ the cavity resonance grows and Rw drops; above 80 kg/m³ the felt becomes acoustically reflective and mid-frequency absorption falls off. The 48 kg/m³ value is a balance point between cavity filling and acoustic mass. Q: Is glass wool safe to use in a machine-room enclosure? A: Yes, when the surface temperature stays under 400 °C. For pumps and compressors at 85–95 dB(A) free-field, a 50 mm glass wool inner layer at 48 kg/m³ inside a damped steel enclosure reaches 35–45 dB(A) insertion loss and stays within the material's rated temperature window. Q: What fire rating do glass wool acoustic panels need? A: For commercial interior use in most jurisdictions the requirement is EN 13501-1 A1 or A2-s1, d0 (non-combustible or limited combustibility, no smoke, no flaming droplets). Glass wool at 24 kg/m³ and above meets A1 by composition; verify the test report cites a third-party lab and a current standard version. Q: Can I install glass wool acoustic insulation myself? A: For partitions and ceiling linings, yes — batts are lightweight and cut with a long knife. For machine-room enclosures and any composite system that needs to meet a rated IL figure, the installation should be carried out by an acoustic contractor because a 5 mm gap at a stud joint can drop the field rating by 10 dB. Q: Where should I go first when I have a number to hit and a budget to keep? A: Start with the dominant constraint — temperature, frequency band, or Rw value — and pick the configuration from the partition/ceiling/enclosure tables in this guide that meets it. Then verify the supplier test report is current and third-party, and have the installer confirm that gaps, penetrations and damping-sheet continuity are within tolerance. ### High-Density Calcium Silicate Board: Properties & Uses URL: https://www.rosetexwool.net/news/high-density-calcium-silicate-board-properties-uses/ 2026-09-04 | Author: Rosetexwool Editorial | Category: industry insight Summary: HD calcium silicate board offers compressive strength and 1050 °C service temperature. Learn how it differs from standard calsil and where it is used. High-density calcium silicate board (HD calsil) is the workhorse version of standard calcium silicate insulation. Where the standard grade is valued for light weight and easy handling, the high-density grade — including our high-density calcium silicate board — trades a little of that lightness for compressive strength, dimensional stability, and load-bearing capacity at temperatures up to 1050 °C. For plant engineers specifying backup insulation behind refractory linings, pipe supports, kiln casings, and aluminum-cell components, HD board is often the only material that satisfies both the thermal and mechanical requirements in one layer. At Rosetex Wool, we manufacture HD calsil boards from xonotlite-based formulations with glass or mineral-fiber reinforcement, press-formed and autoclave-cured. The result is a rigid, non-combustible board with predictable thermal conductivity, low shrinkage, and enough mechanical integrity to be drilled, sawn, and CNC-machined to close tolerances. This guide explains what "high-density" means in practice, how the properties compare to standard calsil, and where the material pays for itself in metallurgy, cement, and other high-load industries. What Makes a Calcium Silicate Board "High-Density"? In industrial insulation terminology, "high-density" calcium silicate board generally starts at about 240 kg/m³. That is already significantly denser than the lightweight micro-porous calsil used for pipe and equipment insulation (commonly 170–220 kg/m³). However, many load-bearing industrial grades are supplied in the 800–1200 kg/m³ range, and specialized structural boards can reach 1200–1500 kg/m³ when the application calls for high compressive strength rather than minimum thermal conductivity. The density difference is not just about weight. It reflects the crystal structure and the reinforcement strategy: - Xonotlite-based formulations dominate the high-temperature segment because the xonotlite crystal phase remains stable to roughly 1050 °C, whereas tobermorite-based boards are normally limited to about 650 °C. - Reinforcement fibers — glass, mineral, or carbon — increase flexural and compressive strength and reduce cracking during thermal cycling. - Autoclave curing under 0.8–1.1 MPa steam pressure at 160–175 °C produces a denser, more uniform microstructure than atmospheric curing. For buyers, the practical meaning is that HD board can sit directly behind a hot face, support the weight of a refractory lining, or form a load-bearing backup layer without the creep or crushing that would occur with lower-density insulation. Where the question is which board form suits the job rather than which grade — board against panel, tile or sheet, across calcium silicate, rock wool, glass wool and ceramic fiber — see the insulation board and panel forms comparison. Key Physical & Mechanical Properties The exact numbers vary with density grade and reinforcement, but typical industrial HD calsil boards fall within the following ranges: Property | Typical HD industrial grade | Notes | Density | 800–1200 kg/m³ | Structural grades up to 1500 kg/m³ | Compressive strength | 0.5–20 MPa | Carbon/mineral-fiber grades at the upper end | Flexural strength | 0.3–18 MPa | Depends on fiber type and board thickness | Thermal conductivity at 100 °C | ≤0.06 W/(m·K) | Measured to ASTM C335 / EN 12667 | Thermal conductivity at 500 °C | ≤0.115 W/(m·K) | Still competitive versus many alternatives | Maximum service temperature | 650–1050 °C | Xonotlite grades at the high end | Linear shrinkage at 1000 °C × 12 h | ≤2.0 % | Critical for long hot-face service | Moisture absorption | ≤10 % | Lower with hydrophobic surface treatment | Hydrophobicity | ≥98 % | Industrial water-repellent grades | The relationship between density and compressive strength is roughly linear: a 10 % increase in density typically delivers about 15 % higher compressive strength and about 10 % higher flexural strength. That is why a 1000 kg/m³ board can support mechanical loads that would crush a 220 kg/m³ pipe-insulation board. At the same time, thermal conductivity does rise slightly with density. The design trade-off, therefore, is to choose the lowest density that still survives the mechanical and thermal loads — not the highest density available. Moisture & Chemical Resistance HD calsil is an inorganic, asbestos-free material. In its standard form it will absorb some water if directly immersed, but industrial grades are supplied with hydrophobic treatment that achieves ≥98 % water repellency and moisture absorption below 10 % by volume. After drying, the board recovers most of its thermal and mechanical properties, which makes it suitable for humid climates, steam-pipe supports, and outdoor installations with weather protection. Chemical resistance is generally good against neutral and alkaline environments. It withstands the flue-gas atmospheres found in cement and metallurgical plants better than organic insulation, and it does not support mold growth or biological attack. Acidic environments below pH 4 can attack the calcium silicate matrix over time, so concentrated acid service should be checked case by case. High-Density vs Standard Calcium Silicate Board Feature | High-density calsil | Standard calsil | Density | ≥240 kg/m³, often 800–1200 kg/m³ | 170–280 kg/m³ typical for insulation | Max temperature | Up to 1050 °C (xonotlite) | Up to 650–800 °C (tobermorite) | Compressive strength | 0.5–20 MPa | 0.4–0.7 MPa typical | Flexural strength | 0.3–18 MPa | 0.2–0.4 MPa typical | Load-bearing backup | Yes | No | Machining tolerance | ±0.5 mm possible with CNC | Limited by lower strength | Best use | Hot-face backup, kiln casing, supports | Pipe and vessel insulation | The standard grade is the better thermal insulator per kilogram, but it cannot carry structural loads or resist the abrasion and compression that occur behind a refractory lining. HD board fills that gap. In many furnaces and kilns the standard approach is a dual-layer system: lightweight calsil or ceramic fiber next to the shell for low conductivity, and HD board at the load-bearing interface. Industrial Applications Metallurgy: Furnaces, Ladles, and Aluminum Cells In steel and non-ferrous plants, HD calsil is used behind the hot-face refractory in walking-beam furnaces, soaking pits, and ladle backup linings. The board absorbs the mechanical load of the refractory, reduces shell temperatures, and keeps heat inside the process. Typical benefits reported in field installations include 15–20 % lower heat loss and 2–3 years longer campaign life compared with older backup designs. Because this is a back-up position, the board is chosen on load and temperature margin rather than conductivity — the distinction is set out in our refractory board selection guide. In aluminum electrolysis, a specialized non-wetting grade is used around cells and troughs. The surface treatment prevents molten aluminum from wetting or penetrating the board, while the high compressive strength (≥15 MPa in carbon-fiber reinforced grades) supports the cell structure. Cell rebuild intervals can be extended and metal losses reduced. Cement: Rotary Kilns, Preheaters, and Tertiary Air Ducts Cement rotary kilns operate with shell temperatures that stress both insulation and steel. HD calsil is placed between the refractory lining and the kiln shell, or as backup in the preheater tower and tertiary-air ducts. The board's low shrinkage at 1000 °C means the lining does not loosen after the first heat-up cycles, and its rigidity simplifies installation on curved shells when pre-cut segments are supplied. A common cement-plant specification calls for 80–120 mm thickness of 800–1000 kg/m³ HD board behind high-alumina refractory, depending on the target shell temperature and the internal process temperature. High-Load Mechanical Backup Any hot equipment that needs a rigid, machinable backup layer is a candidate: reactor vessel supports, gas-turbine exhaust ducts, incinerator linings, and high-temperature flues. In these applications the board may be drilled for anchors, cut into segmented rings, or laminated into thicker blocks. CNC machining to ±0.5 mm is routine for the denser grades, allowing precise fit-up around nozzles and burner openings. For a broader comparison with other rigid insulation options, see our calcium silicate vs ceramic fiber board guide. Custom Sizes, Shapes, and Surface Treatments One of the practical advantages of HD calsil is the ease of customization. Typical supply formats include: - Flat boards: 600 × 300 mm, 500 × 500 mm, 1000 × 500 mm, 1000 × 1000 mm, with thicknesses from 25 mm to 140 mm. - Pre-cut segments: rings, arches, and curved pieces for kilns and vessels. - Special shapes: nozzles, flow tubes, tap-out cones, and cover boards, machined to drawing. Surface treatments can be specified to match the environment: - Plain / smooth — general backup insulation. - Hydrophobic — ≥98 % water repellency for humid or outdoor service. - Non-wetting — for aluminum and other molten-metal contact zones. - Coated / painted — decorative or additional chemical protection where required. When you request a quote, providing the operating temperature, maximum mechanical load, dimensional envelope, and required surface finish lets the supplier recommend the most cost-effective density and reinforcement. Specification Checklist for Buyers Use this checklist when writing a technical specification for HD calcium silicate board: - Service temperature — confirm whether the peak temperature is continuous or cyclic, and whether it exceeds 650 °C (which normally requires xonotlite rather than tobermorite). - Density / compressive strength — match the mechanical load. Backup behind castable refractory typically needs 800+ kg/m³; lower-load applications may use 240–400 kg/m³. - Thermal conductivity — request values at 100 °C, 300 °C, and 500 °C, not just room temperature. - Linear shrinkage — limit to ≤2 % at the maximum service temperature for long campaigns. - Moisture resistance — specify hydrophobic treatment if rain, steam, or wash-down is possible. - Dimensional tolerance — ±1 mm is standard; ±0.5 mm is achievable with machining. - Fire classification — non-combustible A1 equivalent to EN 13501-1. - Anchoring — plan stainless-steel anchors, studs, or clips compatible with the service temperature and board thickness. If you are new to calcium silicate selection, start with what is calsil, then read our calcium silicate insulation buyer's guide and the density & thermal-conductivity spec guide. Conclusion High-density calcium silicate board is not simply a heavier version of standard calsil. It is a distinct engineering material that combines high-temperature stability, mechanical strength, and machinability in a single rigid board. In metallurgy, cement, and other load-bearing thermal applications, it often replaces multi-layer backup designs and reduces both installation complexity and long-term maintenance. Choosing the right density, reinforcement, and surface treatment for the actual operating conditions is the key to getting the best value. A 1500 kg/m³ structural board is overkill for a low-load pipe support, while a 220 kg/m³ insulation board will fail behind a refractory lining. Match the material to the load and temperature, and HD calsil will outlast and outperform softer alternatives. FAQ: Q: What density counts as high-density calcium silicate board? A: Industrial usage generally labels calcium silicate board as high-density from about 240 kg/m³ upward. Load-bearing grades for furnace backup and high-strength applications are usually supplied in the 800–1200 kg/m³ range, with specialized structural boards reaching 1200–1500 kg/m³. Q: How does high-density calsil differ from standard calsil? A: High-density board has higher compressive and flexural strength, lower shrinkage at temperature, and can carry mechanical loads. Standard calsil is lighter and offers lower thermal conductivity per kilogram, but it is not designed for load-bearing backup layers. Q: What is the maximum temperature for high-density calcium silicate board? A: Xonotlite-based high-density boards are typically rated for continuous service up to 1050 °C. Tobermorite-based boards are generally limited to about 650 °C. Always confirm the crystal phase with the supplier for applications above 650 °C. Q: Is high-density calcium silicate board waterproof? A: Standard grades absorb limited water if immersed, but industrial hydrophobic treatments achieve ≥98 % water repellency and moisture absorption below 10 % by volume. For humid, steam, or outdoor service, specify the hydrophobic version. Q: Where is high-density calsil used most? A: Major applications include metallurgical furnaces and aluminum electrolysis cells, cement rotary kilns and preheaters, high-temperature flues, reactor supports, and any location that needs a rigid, machinable backup insulation layer. Q: Can high-density calcium silicate board be machined to custom shapes? A: Yes. The denser grades can be cut with woodworking tools and machined on CNC equipment to tolerances of ±0.5 mm. Common custom parts include kiln segments, nozzles, flow tubes, tap-out cones, and cover boards. Q: What thickness should I choose for 1000 °C service? A: For 1000 °C service behind a hot-face refractory, backup board thickness is normally 80–120 mm depending on the allowable shell temperature and the thermal conductivity of the specific grade. A heat-loss calculation using ASTM C680 or EN ISO 12241 methods is recommended. Q: How does HD calsil compare to ceramic fiber board? A: Ceramic fiber board is lighter and has lower thermal mass, but it has lower compressive strength and is less rigid. HD calsil is the better choice when the backup layer must support load, maintain precise dimensions, or resist mechanical abuse. Q: Does high-density calsil require stainless steel anchoring? A: Yes, rigid backup boards are normally held by stainless-steel anchors, studs, or clips selected for the service temperature. The anchor pattern and material grade should match the board thickness and the expected thermal movement. Q: What certifications should I request? A: Request a test report covering density, compressive strength, flexural strength, thermal conductivity at multiple temperatures, linear shrinkage, and non-combustibility. Typical norms are ASTM C533 for calcium silicate insulation and EN 13501-1 for fire reaction class. ISO 9001 quality-system certification and CE or SGS factory inspection reports are also standard. ### Glass Wool Board Applications: Rigid Board Selection Guide URL: https://www.rosetexwool.net/news/glass-wool-board-applications/ 2026-09-03 | Author: Rosetexwool Editorial | Category: industry insight Summary: An application-driven guide to rigid glass wool board: building envelope, HVAC ductwork and industrial equipment duties, with density, thickness and facing selection tables. Where Rigid Board Earns Its Place Glass wool board is made from the same melt-spun glass fibre as blanket and roll, bonded into a flat, self-supporting panel. That single change in form factor decides most application choices: board holds its shape inside a framed cavity, takes fixing pressure without collapsing, and gives a flat, clean surface for bonded facings. Blanket and roll, by contrast, drape over irregular geometry and win on large uninterrupted areas where speed of coverage matters more than dimensional stability. In practice, glass wool board is the right call when at least one of these is true. The insulation must stay flat and dimensionally stable in service. It sits inside a framed cavity or behind a finish panel. It needs a bonded facing — foil, tissue or film — for vapour control or appearance. Or it must survive light mechanical load during installation and maintenance. When none of those apply, a flexible form is usually the cheaper answer. Our glass wool board vs blanket vs batt guide sets out the three forms side by side on load, geometry, temperature and fixing. Standard supply covers a density range of 24–100 kg/m³ in rigid board form, 100 % non-asbestos, backed by ISO 9001, ASTM C518, REACH and RoHS documentation. The full range sits on our glass wool board product page. For the fibre itself and how the board is formed, see how centrifugal glass wool is made. If you need the flexible form instead — draped over ductwork, rolled across an attic, or wrapped around large-diameter tanks — our glass wool blanket specifications and buying guide covers that side of the range. Where the duty calls for a heavier, higher-temperature rigid board, rock wool board is the usual alternative, and the two materials are compared in detail in our glass wool vs rock wool comparison. Building Envelope Applications Building work is where rigid board sees the highest volume, and it is where density selection matters most. The pattern is consistent: pick density for how the board is held and handled, then pick thickness for the thermal target. - External walls (ventilated facade, cavity wall, curtain-wall spandrel). Board is friction-fitted between studs or fixed to the substrate behind a rainscreen. Medium density — roughly 48–64 kg/m³ — is the common choice: stiff enough to stay put without slumping over time, light enough not to load the fixing system. Thickness typically runs 50–100 mm depending on the target U-value. On a ventilated facade a reflective foil facing also cuts solar radiant gain into the cavity, which in a cooling-dominated climate is often worth more than the same money spent on extra board thickness. - Roofs and metal decks. Board sits over or under the deck, often in two layers with staggered joints to break thermal bridges. Higher density, 64–100 kg/m³, is used where the roof takes foot traffic during maintenance. Because a roof deck moves, specify water repellency of at least 98 % and an elastic recovery of at least 90 % so the board tolerates small movements without opening joints. - Internal partitions and floors. Here the driver is acoustic, not thermal. Board fitted in stud cavities or beneath a floating floor cuts both airborne and impact noise. Where a decorative acoustic finish is needed, the rock wool acoustic panels range covers dedicated treatments. - Cold storage and refrigerated rooms. Board with an impermeable facing handles low-temperature envelope work, with every joint taped so the vapour barrier stays continuous around the whole envelope. Building application | Density (kg/m³) | Typical thickness | Facing | Additional check | External wall cavity | 48–64 | 50–100 mm | Unfaced or tissue-faced | Compressive strength ≥ 25 kPa | Ventilated facade | 48–80 | 60–120 mm | Black tissue or unfaced | Reflective facing for solar gain | Roof / metal deck | 64–100 | 50–150 mm | Unfaced or bitumen-compatible | Water repellency ≥ 98 %, elastic recovery ≥ 90 % | Internal partition | 32–48 | 50–75 mm | Unfaced | Air gap retained behind board | Cold store envelope | 48–80 | 80–150 mm | Foil or PVC vapour barrier | Barrier continuous, joints taped | HVAC and Ductwork Applications Ductwork is the second large application family, and it is the one where facing selection is decisive rather than optional. - External duct insulation. Board is wrapped and pinned around rectangular duct, then finished with a foil or FSK facing. That facing is not decoration — it is the vapour barrier that stops warm, humid air from reaching a cold duct surface and condensing inside the insulation. - Duct liner. Fitted inside the duct, board acts as an acoustic absorber that cuts fan and airflow noise. A medium-density board with a tough black tissue facing resists the airstream, and all cut edges are sealed to stop fibre erosion. - AHU and plenum casing. Board lines casing panels to deliver thermal and acoustic performance together, which is usually why it is specified over a plain thermal liner. Condensation is the failure mode to design against on any chilled-water or cold supply-air system. Where moisture exposure is a genuine risk, our note on whether glass wool blanket is waterproof sets out what the material does and does not tolerate once wet. Industrial Equipment and Enclosed Systems Rigid board suits flat and gently curved industrial surfaces, where it is usually cut to fit a frame rather than draped: - Equipment casing and panel infill. Cut board fills framed panels on tanks, vessels, precipitator casings and machinery enclosures. - Flat and large-radius surfaces. Board is used where the radius is large enough for the panel to lie without cracking. Below roughly 300–400 mm radius, a flexible or preformed form fits better and avoids a spring-back gap at the joints. - Acoustic enclosures. Perforated facing over board inside an enclosure absorbs machinery noise at source instead of letting it into the workspace. - Hot equipment up to the binder limit. With metal cladding over the top, board handles continuous hot duty to roughly 230 °C, provided the density is high enough — 64–96 kg/m³ — to resist vibration and cladding fixings. For pipe insulation, board is not the usual answer. Preformed pipe sections match the bore correctly and hold their geometry around the circumference; board is used on pipework mainly as flat inserts at pipe supports and as cladding on boxed-in headers. Our industrial pipe insulation materials guide covers that selection properly. On fire performance, unfaced glass wool is non-combustible, while the classification of a faced product depends on the facing. Full detail sits in our dedicated article, is glass wool fireproof. The spec-side reading for rigid board — density classes, lambda, compressive strength and facings — is covered in glass wool insulation board: rigid board selection & spec. Selecting Density, Thickness and Facing Three variables, three different jobs. Keeping them separate prevents most specification errors we see in enquiries. Selection driver | Variable to change | Practical guidance | Thermal performance | Thickness | Set the target U-value first, then read thickness off it — not the other way round | Strength and handling | Density | 24–32 kg/m³ for friction-fit cavities; 48–80 kg/m³ where board is fixed and handled; 80–100 kg/m³ where it carries load | Acoustic absorption | Density + facing | Open or tissue facing absorbs; a sealed foil facing reflects sound back into the space | Vapour and moisture control | Facing | Foil or FSK on chilled systems; black tissue on duct liner; unfaced where the board stays dry | Why Higher Density Is Not Always Better Density drives thermal performance, acoustic performance and strength in three different directions, so there is no single best figure — only a best band for the duty. - Thermal performance peaks in the middle. Across roughly 24–64 kg/m³ the fibre structure holds enough still air to keep conductivity low without creating continuous solid conduction paths. Below about 24 kg/m³ the air pores grow large enough for internal convection to start, and conductivity rises. Above about 64 kg/m³ the fibre pack becomes dense enough that solid conduction through the glass itself begins to dominate, and conductivity rises again. - Acoustic absorption peaks lower still. The most useful absorption band is roughly 32–48 kg/m³. Denser board raises flow resistivity to the point where sound is reflected at the surface instead of entering the panel, so absorption falls off even as the board gets mechanically stronger. - Compressive strength only ever rises with density. Typical figures are around 20 kPa at 24 kg/m³, 40 kPa at 48 kg/m³ and 80 kPa at 96 kg/m³, measured to ASTM C165. This is the one property where buying more density always buys you more. - Cost rises with density, roughly 8–12 % for every additional 20 kg/m³. The practical rule: buy density for strength and handling, and buy thickness for thermal performance. Paying for density to chase a lower U-value is the most common way to overspend on this material. Thermal Conductivity and Temperature For room-temperature design work, declared conductivity for rigid board normally falls in the 0.032–0.044 W/m·K band. Conductivity is not a constant — it rises with mean temperature — so hot-duty figures must be read at the actual operating mean rather than at ambient. If you are insulating a hot surface, state the mean temperature with your enquiry; the declared ambient figure will understate real heat loss. Where sound control is the primary duty, the usual starting point is 32–48 kg/m³ at 50–100 mm, with the facing chosen for absorption rather than vapour sealing. Low-frequency control depends far more on thickness and on the cavity behind the board than on density, so adding density to fix a low-frequency problem rarely pays off. Standard resin-bonded board is rated for continuous service to roughly 230 °C. Above that the binder, not the glass, becomes the limiting factor — the glass fibre itself tolerates far more, but the continuous rating is set by what holds the panel together. A high-temperature bonded grade should be requested at enquiry stage rather than discovered on site. Specification by Application: HVAC and Industrial The building table above covers the envelope. The table below covers the mechanical and industrial duties, where the governing constraint is usually temperature, vibration or facing durability rather than a U-value target. Application | Density (kg/m³) | Thickness | Facing | Governing check | External duct insulation | 32–48 | 30–50 mm | Foil or FSK, all joints taped | Vapour barrier continuity | Duct liner (acoustic) | 48–64 | 25–50 mm | Black tissue, edges sealed | Airstream erosion resistance | AHU and plenum casing | 48–64 | 40–80 mm | Tissue or foil | Thermal and acoustic combined | Equipment casing / panel infill | 64–96 | 50–100 mm | Unfaced or tissue | Vibration and handling load | Acoustic enclosure | 48–64 | 50–100 mm | Perforated facing over board | Absorption at source | Hot equipment to 230 °C | 64–96 | 50–120 mm | Unfaced, under metal cladding | Continuous temperature rating | Installation and Fixing Methods Board performance on site is mostly a fixing question. The failure modes that show up repeatedly are the same four: - Compressed board. Over-tightening banding, or forcing an oversized panel into a cavity, crushes the fibre and raises thermal conductivity. Cut to fit — never compress to fit. - Open joints. Butt joints must be tight, and on multi-layer work staggered between layers. A gap is a thermal bridge on hot work and a condensation path on cold work. - Broken vapour barrier. Every facing joint and every penetration must be taped or sealed. One unsealed seam on a chilled line can wet an entire run. - Unprotected edges. Cut edges on duct liner and exposed board should be sealed or covered to stop fibre release and edge erosion over time. Common fixing methods are impaling pins with self-locking washers on duct and sheet-metal surfaces, adhesive on clean masonry and board-on-board work, and banding or wire on large equipment. Facings are taped after fixing, and the whole assembly is weatherproofed wherever it sits outdoors. Three Details That Decide Long-Term Performance - Grade the density on multi-layer work. On thick or hot build-ups, fit a lower-density inner layer — around 32 kg/m³ — against the substrate and a higher-density outer layer at around 64 kg/m³, with joints staggered between layers. The inner layer does the insulating; the outer layer takes the handling load and gives cladding fixings something solid to bite into. Staggering removes the straight-through path that a single aligned joint leaves behind. - Leave an air gap where sound matters. In stud partitions and acoustic enclosures, a 50–100 mm air gap behind the board improves low-frequency absorption substantially — more than any realistic increase in board density. Do not pack the cavity tight to the structural face if low-frequency control is the goal. - Protect the installer, then the board. Glass wool fibre is mechanically irritating. Cut and fit with gloves, long sleeves and eye protection, and add respiratory protection wherever cutting generates dust in an enclosed space. Board that is cut cleanly and sealed at the edges also sheds less fibre in service. Specification Checklist for Enquiries A clean enquiry gets a clean quote. Have these eight items ready before you send it: - Application — external wall, roof, duct external, duct liner, equipment casing, or cold store - Density required, or the load the board has to carry - Board thickness and the target U-value or R-value - Facing type, or the vapour-control requirement - Maximum continuous service temperature, and the mean temperature if it is a hot duty - Standard the project is certified to — ASTM C612, EN 13162 or GB/T 13350 — so test reports can be matched to the destination market - Panel dimensions and any tolerance limits - Quantity, destination port, and whether acoustic performance is specified Related products: Glass Wool Blanket Related applications: Building, Cryogenic Insulation FAQ: Q: What is glass wool board used for? A: Rigid glass wool board is used across four main application families: building envelope work (external walls, ventilated facades, roofs, internal partitions and cold stores), HVAC ductwork (external duct insulation, duct liner and air-handling unit casings), industrial equipment and enclosures (panel infill, acoustic enclosures and cladding on flat or large-radius surfaces), and cold-service work where a taped vapour barrier is required. Within pipework it has a narrower role — preformed pipe sections are the correct form for the pipe itself, while board is used as flat inserts at pipe supports and as cladding on boxed-in headers. Q: What density glass wool board should I choose? A: Match density to how the board is held and handled rather than to thermal performance. Use 24–32 kg/m³ for friction-fit cavities where the board carries no load, 48–80 kg/m³ where it is fixed and handled during installation, and 80–100 kg/m³ where it must carry load or take maintenance traffic. Thermal performance peaks in the 24–64 kg/m³ band and acoustic absorption peaks around 32–48 kg/m³, so specifying above roughly 64 kg/m³ buys strength, not insulation. Compressive strength rises throughout, at roughly 20 kPa at 24 kg/m³, 40 kPa at 48 kg/m³ and 80 kPa at 96 kg/m³. Q: Is glass wool board suitable for HVAC ductwork? A: Yes, in two distinct roles. As external duct insulation, board is wrapped and pinned around rectangular duct and finished with a foil or FSK facing that acts as the vapour barrier — without a continuous sealed facing, warm humid air reaches the cold duct surface and condenses inside the insulation. As duct liner, board is fitted inside the duct to absorb fan and airflow noise, using a medium-density board with a tough black tissue facing that resists the airstream, with all cut edges sealed against fibre erosion. Q: What thickness of glass wool board do I need? A: Work backwards from the thermal target rather than picking a round number. Set the required U-value or R-value from your energy code, then read the thickness off the board's declared conductivity — remembering that conductivity rises with mean temperature, so a hot-duty figure will be higher than the ambient one. Typical thicknesses are 50–100 mm for external walls, 50–150 mm for roofs, 30–50 mm for external duct insulation and 50–120 mm for hot equipment. Where low-frequency noise is the problem, extra thickness does more than extra density. Q: Can glass wool board be used outdoors? A: Yes, but the board itself is not a weathering layer and must always be protected. Outdoors the assembly needs a continuous vapour barrier on the warm side and a weatherproof cladding or rainscreen over the top. On roofs, specify water repellency of at least 98 % and elastic recovery of at least 90 % so the board tolerates deck movement without opening joints. Unfaced board left exposed to rain will absorb water, lose thermal performance and, on cold service, drive corrosion under the insulation. Q: How is glass wool board fixed in place? A: Method follows substrate. Impaling pins with self-locking washers are standard on ductwork and sheet-metal surfaces. Adhesive works on clean masonry and for board-on-board second layers. Banding or wire secures board to large equipment. On thick or hot build-ups, use two layers with graded density — around 32 kg/m³ inner and 64 kg/m³ outer — and stagger the joints between layers. Cut to fit rather than compressing to fit, and seal every facing joint afterwards. Q: What is the maximum service temperature of glass wool board? A: Standard resin-bonded glass wool board is rated for continuous service to roughly 230 °C. Above that temperature the organic binder, not the glass fibre, becomes the limiting factor — the fibre itself tolerates considerably more, but the continuous rating is set by what holds the panel together. For duties above 230 °C, request a high-temperature bonded grade at enquiry stage. On pipework above roughly 400 °C, rock wool or a calcium silicate build-up is the usual answer rather than glass wool. Q: Which density and thickness should I use where sound control is the main goal? A: Start at 32–48 kg/m³ with 50–100 mm thickness. Absorption peaks in that band: denser board raises flow resistivity until sound reflects off the surface instead of entering the panel, so absorption falls even though the board is stronger. Low-frequency noise responds much better to extra thickness and to a 50–100 mm air gap behind the board than to a density increase, so if the complaint is a low rumble, spend the budget on depth and cavity rather than on a heavier panel. A sealed foil facing will reflect sound back into the room, so choose an open or tissue facing when absorption is the aim. Q: Can glass wool board be used on high-temperature pipework? A: Up to roughly 230 °C the material is fine, but form matters more than temperature. Preformed pipe sections match the bore and hold their shape around the circumference, which board cannot do on small diameters, so board on pipework is normally limited to flat inserts at pipe supports and cladding on boxed-in headers. Above 230 °C, or anywhere the board must carry more than about 60 kPa, specify a high-temperature bonded grade or move to rock wool board. Above roughly 400 °C the usual specification is rock wool or a calcium silicate and aerogel composite build-up. Q: Why is two-layer insulation with staggered joints recommended? A: Because a single layer leaves a straight path for heat at every joint. Two layers let you stagger the joints so no gap runs through the full thickness, and let you grade the density — a lower-density inner layer does the insulating while a higher-density outer layer takes the handling load and gives cladding fixings something solid to bite into. The result is a lower effective conductivity than the same total thickness in one layer, and a build-up that survives maintenance traffic without crushing. ### Aerospace & Nuclear Insulation: Materials for Extreme Environments URL: https://www.rosetexwool.net/news/aerospace-nuclear-insulation/ 2026-09-03 | Author: Rosetexwool Editorial | Category: industry insight Summary: Material families and selection criteria for spacecraft thermal protection and nuclear primary-loop insulation — aerogel composites, porous ceramics, and BPE / HDPE composites. Industrial insulation materials and aerospace & nuclear insulation share the same goal — slowing heat flow — but the two extremes raise the bar to a different universe. Aerospace hardware has to survive re-entry surface temperatures above 3000 °C and shadow-side cold down to -196 °C, while staying extremely lightweight (densities below 0.2 g/cm³) and passing strict vacuum outgassing tests. Nuclear plant insulation must hold dimensional and thermal stability under combined high temperature, high pressure (typically 300–700 °C, >15 MPa) and intense neutron + gamma radiation (10⁶–10⁸ Gy), while in many cases pulling double duty as a radiation shield. This guide maps the materials used for both applications side-by-side, lines up the performance constraints that drive the choices, and gives a selection matrix a procurement or design engineer can actually use. For general industrial pipe and equipment insulation, see our industrial pipe insulation materials guide. For cryogenic pipe work that overlaps with the -196 °C end of the aerospace/nuclear range, see our cryogenic pipe insulation guide. Scope note. This article is about extreme-environment thermal and radiation performance. General fire protection for defense platforms is covered separately in our aerospace and defense thermal insulation materials page; naval fire protection is covered in our marine fire insulation standards page. Both are referenced here only as complementary reading — they are not the subject. Why aerospace and nuclear insulation are not "industrial-plus" Three physical conditions separate these regimes from ordinary industrial insulation: rapid thermal cycling, vacuum or radiation-coupled environments, and zero-tolerance for weight (aerospace) or for activation / degradation over decades (nuclear). Each forces material choices that simply do not exist in petrochemical, cement, or power-plant insulation catalogs. A useful way to frame the difference is by asking what failure looks like. On a satellite, a few extra kilograms of insulation mass directly raises launch cost by roughly $10,000 per kilogram; on a reactor primary loop, a 5% drop in thermal performance over ten years can push a safety-related component past its qualified envelope. Those two failure costs drive very different material solutions. The table below summarises the four constraints that govern almost every selection decision in both sectors: Constraint | Aerospace limit | Nuclear limit | Industrial reference | Service temperature | -200 °C to +3000 °C (gradient inside one vehicle) | -196 °C to +1400 °C | -50 °C to +650 °C | Density | typically < 0.2 g/cm³ for hot structure; < 0.3 g/cm³ for engine | usually > 100 kg/m³ for primary-loop insulation; 1.5–12 g/cm³ for shielding structures | 24–200 kg/m³ | Outgassing / radiolysis | TML ≤ 5 %, CVCM ≤ 1 % (ASTM E595) | H₂ emission < 1 µg/cm²·day; performance decay < 5 % / 10 yr | not qualified | Certification | DO-160G, NASA materials specs, GB/T 34517 outgassing | ASME BPVC Section III (Div. 1, 2, 3, 5), ASME NQA-1, ISO 19443 | GB 8624 fire class, GB/T 4272 | Each constraint is unpacked in its own section below. The aerospace thermal-environment spectrum Four thermal environments dominate spacecraft and launch-vehicle design, and they are different enough that one material rarely covers all four: - Re-entry and rocket-engine plumes. Surface temperatures reach 1500–3000 °C for tens of seconds. Heat-flux density is extreme and convective cooling is essentially absent, so the insulation must carry the entire thermal load through its own heat capacity plus front-face ablation or re-radiation. Carbon-based aerogel composites (density 0.12–0.2 g/cm³, λ 0.044–0.06 W/(m·K)) and reusable high-temperature blankets made from porous oxide ceramics (mullite, magnesium-aluminate spinel) are the workhorses. - Deep-space cold-soak. In shadowed regions of a Mars orbiter or lunar lander, equilibrium temperature can drop to about -196 °C. The requirement here is stable low thermal conductivity rather than high temperature resistance — silica aerogel (λ ≤ 0.020 W/(m·K) at 25 °C) is the standard. - Orbital thermal cycling. LEO spacecraft see ±100 °C swings in minutes as they pass in and out of sunlight. The insulation must survive thousands of these cycles without micro-cracking or delamination — that rules out most rigid ceramic boards unless they are properly cushioned. - Internal fire protection. Crew or payload bays still need fire barriers, typically 3–5 mm flexible composite blankets with a tensile strength around 10 MPa and elongation around 150 % so they can wrap irregular geometry. Across all four environments, the same property shows up: outgassing. Total mass loss (TML) must stay under 5 % and collected volatile condensable materials (CVCM) under 1 % per ASTM E595, with additional project-level limits on water vapour recovery. This is why aerospace grades of familiar materials — silica aerogel, polyimide films, ceramic-fibre textiles — look superficially similar to industrial grades but cost an order of magnitude more per kilogram. The nuclear-environment spectrum Nuclear plant insulation is governed by three overlapping extremes: thermal, mechanical, and radiation. Each component on the primary loop, in the containment, or in the spent-fuel pool sees a different combination. - Primary loop steam and feedwater piping. 300–700 °C surface, high pressure, sustained gamma + neutron flux. The classical choice is microporous calcium silicate (density 100–200 kg/m³, λ 0.044–0.06 W/(m·K)) wrapped with a ceramic-fibre blanket; modern plants increasingly replace that with rare-earth-doped aerogel composites that cut thickness in half while adding neutron-shielding performance. - Reactor vessel and steam-generator enclosures. Shielding plus insulation in one layer: boron-containing polyethylene (BPE) at 0.92–1.2 g/cm³ absorbs thermal neutrons efficiently (≥ 95 % in standard formulations) and is paired with HDPE composites loaded with Sm₂O₃-B₄C or PbWO₄-B₄C when gamma shielding is also needed. Fifteen centimetres of such composite can deliver > 97 % neutron shielding and > 72 % gamma shielding simultaneously. - Containment penetrations and cable rooms. Where weight matters more than temperature, glass foam (closed-cell, A-class non-combustible, near-zero water absorption) remains the default. Service range -196 °C to +650 °C, density 220–300 kg/m³. - Generation-IV high-temperature reactors. Components run near 1400 °C under irradiation. Only a narrow class of materials qualifies; tungsten-carbide / high-entropy-alloy composites (WC-HEA, density 8–12 g/cm³, compressive strength ~34 MPa) are emerging as structural-insulation hybrids. The radiation constraint deserves a separate table because it is what most often disqualifies otherwise excellent industrial insulation: Material | Service under γ + n flux | Typical dose limit | Why it survives | Calcium silicate | acceptable in primary loop | ~10⁶ Gy | inorganic crystalline phase, low hydrogen content | Ceramic-fibre blanket | acceptable | ~10⁷ Gy | aluminosilicate glass is radiation-tolerant | Rare-earth aerogel composite | qualified for primary loop | > 10⁸ Gy | oxide matrix, no organic binder | HDPE-based composites | containment & storage only | ~10⁵ Gy | hydrogen-rich, radiolysis limits lifetime | Steel / WC-HEA structural shielding | reactor internals | > 10⁸ Gy | metallic bonding, no organic phase | Material families used in both sectors Looking at the two regimes together, five material families cover roughly 90 % of qualified selections. They are presented in order of typical use temperature: - Silica aerogel composites. Operating window -200 °C to +1200 °C, λ 0.012–0.020 W/(m·K), density 0.087–0.15 g/cm³. Satellite electronics enclosures, cryogenic fuel tanks, and increasingly nuclear primary-loop retrofits. - Carbon-based aerogel composites. Operating window -200 °C to >3000 °C, density 0.12–0.2 g/cm³, λ 0.044–0.06 W/(m·K). Re-entry thermal protection, rocket-engine nozzle vicinity, hypersonic leading edges. - Porous oxide ceramic insulators. Mullite and magnesium-aluminate spinel fibre boards and tiles, porosity >80 %, density 0.2–0.5 g/cm³. Reusable thermal protection, deep-space thermal control, certain high-temperature reactor components. - Polyimide films and flexible high-temperature composites. Transparent polyimide films (solar transmittance >0.8) for solar array and optical-window protection; flexible fire-insulation composites (10 MPa tensile, ~150 % elongation) for internal compartment fire barriers. - Boron-containing HDPE composites. BPE, Sm₂O₃-B₄C/HDPE, PbWO₄-B₄C/HDPE. Density 0.92–1.2 g/cm³; combine neutron shielding with low thermal conductivity. Reactor containment, fuel-storage containers, cable-penetration shielding. For nuclear-grade piping above 650 °C, calcium silicate and ceramic-fibre blanket stacks remain the workhorse combination, while for cryogenic piping and storage the relevant grade of foam glass is usually combined with an aerogel layer where space is tight. Our nano aerogel insulation blanket is the industrial-bench counterpart of the aerospace aerogel grade. Certification pathways: DO-160 vs ASME BPVC The qualification routes for the two industries are deliberately different. Aerospace insulations are certified under environmental test standards such as RTCA DO-160G (temperature, altitude, humidity, vibration, shock — 18 test sections) plus project-specific NASA material specifications and ASTM E595 outgassing per GB/T 34517-2017. The test programme is short but very wide; failure modes are dominated by thermal cycling, vibration and outgassing. Nuclear-grade insulations are qualified under ASME BPVC Section III (with Divisions 1, 2, 3 and 5 covering different component classes) and the nuclear-quality-assurance programme ASME NQA-1, with ISO 19443 as the international equivalent. The test programme is narrow but very long: irradiations last months, ageing tests run for 40-year design lifetimes, and every supplier must be part of a documented chain of quality control with full traceability to raw material lots. This is why the same chemistry sold into aerospace and into nuclear often costs a different order of magnitude even when the underlying material is identical. Aspect | Aerospace (DO-160 / NASA) | Nuclear (ASME BPVC III / NQA-1) | Test horizon | weeks to a few months | years to decades | Primary failure modes | thermal cycling, outgassing, vibration | irradiation ageing, thermal ageing, corrosion | Documentation focus | per-batch traceability to formula | per-component traceability with 40-year records | Acceptance philosophy | pass/fail on a small set of standard tests | qualified + surveilled throughout service life | Selection matrix by application The matrix below maps the most common qualification cases to the material family that is normally selected. It is not exhaustive; project-specific qualification always overrides generic recommendations. Application | Service temperature | Dominant constraint | Typical choice | Satellite electronics enclosure | -50 °C to +150 °C | outgassing, mass | silica aerogel blanket | Rocket-engine nozzle vicinity | up to +3000 °C | heat-flux, ablation | carbon aerogel composite | Deep-space thermal control | -200 °C to +1400 °C | thermal cycling | porous oxide ceramic tile | Crew / payload fire barrier | -50 °C to +300 °C | fire, flexibility | flexible ceramic-fibre composite | Reactor primary loop | +300 °C to +700 °C | γ + n flux, ageing | calcium silicate + ceramic-fibre wrap, or rare-earth aerogel composite | Containment penetration | < +300 °C | neutron + γ shielding | Sm₂O₃-B₄C / HDPE composite | Spent-fuel storage | < +300 °C | long-term shielding | BPE or PbWO₄-B₄C / HDPE | Generation-IV high-temperature structure | up to +1400 °C | γ + n flux + temperature | WC-HEA composite | For procurement, three questions decide the answer in most cases: (1) what is the maximum and minimum service temperature and how fast does the temperature cycle, (2) is vacuum or radiation present and at what dose rate, and (3) what weight, space or geometry constraints apply. If the answers are uncertain, the safer default in aerospace is the silica aerogel family, and in nuclear it is calcium silicate or BPE depending on whether shielding is required. Boundary with general industrial insulation It is worth being explicit about what this guide does not cover. Petrochemical, cement, power-generation and HVAC insulation — which is what most procurement teams are familiar with — lives in a much narrower window: typically -50 °C to +650 °C, no vacuum, no sustained radiation, no launch-cost penalty per gram. The materials are calcium silicate, rock wool, glass wool, ceramic fibre boards, elastomeric foam, and (more recently) aerogel-enhanced industrial blankets. Our industrial pipe insulation materials page is the entry point for that universe; this article is its upstream cousin for the two extremes where ordinary industrial insulation is either illegal, ineffective or both. For the catalogue view of the high-temperature non-combustible form most often listed in the selection matrix, see our ceramic-fibre blanket product page; the broader aerospace and defence programme context is on our aerospace and defense applications page. See our nuclear power insulation applications for reactor auxiliary and containment insulation systems. Related products: Calcium Silicate Pipe Related applications: Aerospace & Defense FAQ: Q: Are aerogel composites approved for nuclear primary-loop piping? A: Yes, in retrofits and in some Generation-III+ designs. Qualification is done case-by-case under ASME BPVC Section III Division 1 with extended ageing testing, because the operating temperature window is similar to a high-pressure steam line. Q: What is the minimum density currently achievable for an aerospace-grade insulator? A: About 0.087 g/cm³ for pure silica aerogel monoliths; densities in the 0.12–0.2 g/cm³ range are more common for reinforced aerogel blankets that can be handled and installed on a vehicle. Q: How is outgassing measured and what are the limits? A: The standard test is ASTM E595 (also implemented as GB/T 34517-2017): samples are held at 125 °C under high vacuum for 24 hours, then total mass loss must be ≤ 5 %, collected volatile condensable materials ≤ 1 %, and recovered water vapour ≤ 0.1 %. Some programmes impose stricter project limits. Q: Does boron-containing polyethylene actually shield neutrons? A: Yes. A 15 cm thickness of standard BPE or Sm₂O₃-B₄C/HDPE composite absorbs over 97 % of thermal neutrons from a ²⁵²Cf source, and simultaneously contributes roughly 72 % gamma shielding for the Sm₂O₃ formulation. Q: Why is the thermal-shock limit quoted as ΔT > 1000 °C/s for some materials? A: Because re-entry and rocket-engine exposure can impose heating rates of that order on the insulation surface. The material has to survive the gradient without cracking or delaminating, which is verified with flame-shock or laser-shock tests at progressively higher heat flux. Q: How long should a nuclear-grade insulation system last? A: The qualified design life of nuclear-safety-related insulation is typically 40 years, with performance decay below 5 % over that period. This is verified by accelerated ageing tests under combined temperature and irradiation. Q: What is the cheapest way to upgrade an existing nuclear primary loop to better insulation? A: In most plants the cheapest improvement is to retrofit the existing calcium silicate layer with an inner sleeve of rare-earth aerogel composite, which roughly halves the required thickness and lowers the outer surface temperature by 30–40 °C at the same pipe temperature. Q: Does this article overlap with the aerospace-defense fire-protection page? A: They are complementary. Aerospace-defense fire protection covers fire-resistance and impact scenarios in military platforms, while this article covers extreme thermal environments and radiation shielding. The two subjects meet only on internal compartment fire-barrier materials. Q: Can industrial aerogel blankets be used in aerospace applications? A: No. Industrial aerogel blankets are not qualified under DO-160 or NASA material specifications, and they are not covered by the same outgassing documentation. Using one in a flight article invalidates the qualification chain. Q: Where should a buyer start when the specification is uncertain? A: Identify the dominant constraint — temperature, dose rate, or mass — and pick the matching row from the selection matrix above. The material families in this guide then narrow to one or two candidates; project qualification and supplier audit complete the selection. ### Pyrogel Insulation Thickness: Chart & Selection Guide URL: https://www.rosetexwool.net/news/pyrogel-insulation-thickness/ 2026-09-02 | Author: Rosetexwool Editorial | Category: industry insight Summary: A ready-to-use pyrogel insulation thickness chart by temperature and pipe size, plus CUI logic, layering splits and the single-vs-double economic breakpoint. What This Guide Covers Choosing the right pyrogel insulation thickness is mostly a table-lookup plus a quick calculation — not a materials-science debate. This manual gives you a ready-to-use thickness chart by operating temperature and pipe diameter, the calculation method behind it, corrosion-under-insulation (CUI) adjustments, layering logic, and the single-vs-double economic breakpoint. It is written for plant engineers, EPC specifiers and procurement teams who need a defensible number, fast. Note on terminology: "pyrogel" is the phrase most buyers search for, and it correctly describes a family of pyrogel-type aerogel flexible blankets. This guide treats them generically as aerogel-type insulation and does not endorse any single brand. Pyrogel Insulation Thickness Chart Use the table below as a first-pass selection. Values are typical thickness ranges (mm) of aerogel-type blanket needed to hold a target surface temperature on clean, bare pipe. Operating Temp | DN50 (2") | DN100 (4") | DN150 (6") | DN200 (8") | 150 °C | 5–8 | 6–10 | 8–12 | 10–14 | 300 °C | 8–12 | 10–15 | 12–18 | 14–20 | 500 °C | 12–18 | 15–22 | 18–26 | 20–30 | Cryogenic –196 °C | 18–24 | 22–28 | 25–32 | 28–36 | Two rules of thumb fall straight out of the chart: - Thickness rises with temperature. Every 200 °C step adds roughly 4–8 mm for the same pipe. - Thickness falls as pipe diameter grows. A larger pipe has more surface area per unit length, so the same heat-flow limit needs less insulation depth. These are starting points. Always verify against the two hard limits in the next section before you release a specification. How to Read the Chart (and the Two Limits That Override It) The chart assumes a standard target: external surface temperature at or below about 50 °C for personnel protection, and heat loss within the project energy code. - Surface-temperature limit. If the calculated surface runs hotter than 50 °C, add thickness in 2–3 mm steps until it drops below the limit. This overrides the chart. - Energy-code limit. Some projects specify a maximum heat-loss rate (W/m). When that is the binding constraint — common on long, hot lines — the chart value is often too thin and you step up one pipe-size column. For the underlying material-property inputs (conductivity by temperature, density, fire class), see our pipe insulation materials guide. Thickness Calculation Method When you need an exact number rather than a chart estimate, use the thermal-resistance method. For flat surfaces: δ = R × λ For pipes, the resistance of a cylindrical layer is: R = ln((D + δ) / D) / (2π × λ) where: - δ = insulation thickness (m) - λ = thermal conductivity of the aerogel-type material (W/m·K) - D = pipe outer diameter (m) - R = required thermal resistance (m²·K/W), derived from the temperature drop you must achieve Worked example. DN100 pipe (D ≈ 0.11 m), process temperature 300 °C, ambient 25 °C, target surface ≤ 50 °C. With a representative aerogel-type conductivity of about 0.020 W/m·K, the required aerogel-type thickness lands near 10–15 mm — a fraction of the depth a conventional fibrous blanket would need for the same resistance. For the direct side-by-side with mineral wool on pipes, our pyrogel vs mineral wool pipe insulation guide works through the numbers. Keep the comparison clean: this article is a selection manual, not a cost-versus write-up. The broader cost framework sits in our aerogel insulation thickness and cost guide. CUI Thickness Logic Corrosion under insulation is the quiet killer of piping systems in coastal, offshore and chemical plants. Aerogel-type blankets help because they are hydrophobic (water uptake typically well below 1 %) and breathable, so moisture does not pool against the steel. Thickness adjustments for CUI risk: - Add ~30 % to the minimum thermal thickness in high-risk zones (NACE Class 4 — coastal, cyclic-wet, chemical). The extra depth preserves the dew-point margin after any micro-leak. - Vibration and mechanical-load areas (pumps, compressors, supports) take the upper end of the chart range — roughly 10–20 mm — to resist compaction. - No separate vapor barrier is usually required when the aerogel-type layer is hydrophobic and the cladding is intact, which removes a common CUI entry path. The economic upside is large: a hydrophobic aerogel-type system typically needs roughly one-quarter the inspection and re-wrap frequency of a wetted fibrous system over a 15-year life. Multi-Layer Composite Thickness Allocation On most projects the optimum is not "all aerogel" but "aerogel where it earns its cost." Use aerogel-type as the core insulation layer and pair it with a structural, fire-rated conventional layer. Recommended thickness splits (aerogel-type share of total): Outer Pairing | Aerogel-Type Share | Conventional Share | Rock wool | 25–30 % | 70–75 % | Glass wool | 20–25 % | 75–80 % | Calcium silicate | 15–20 % | 80–85 % | The logic is thermal-resistance addition: total R = R_aerogel + R_conventional. You put the thin, low-λ layer on the hot side where it contributes the most resistance per millimetre, and the cheaper layer on the outside for structure, impact resistance and fire rating. Keep the aerogel-type share inside the ranges above; pushing it much higher usually costs more than it saves unless the system is severely space-limited. Example. A DN100, 300 °C line needing total R ≈ 1.05 m²·K/W: ~10 mm aerogel-type (R ≈ 0.50) plus ~40 mm rock wool (R ≈ 0.55) reaches the target. Swapping to 100 % aerogel-type would need ~21 mm — more expensive per metre yet offering little extra resistance once the conventional share is already small. Single-Layer vs Double-Layer Economic Breakpoint Whether to run a single aerogel-type layer or a composite comes down to one number: the aerogel-type share of total thickness at the economic crossover. - High temperature (>300 °C): single-layer aerogel-type wins once its share passes about 30 % of total thickness; below that, a composite is cheaper. - Mid temperature (150–300 °C): the breakpoint is about 25 %. - Low temperature (<150 °C): the breakpoint is about 20 %. Why the breakpoint exists: aerogel-type material costs more per mm than the conventional pairing, but it also costs less to install per mm of equivalent resistance. Above the crossover, the saved installation volume outweighs the higher material price. Below it, adding the conventional layer is the cheaper route to the same R. For the full cost model and payback math, see the aerogel insulation thickness and cost guide. Quick Selection Checklist - Record the operating temperature and pipe outer diameter. - Read the chart for the matching row/column. - Apply the CUI add-on (+30 % in coastal/chemical zones; upper range in vibration areas). - Check the two limits — surface ≤50 °C and energy-code heat loss. Step up if either binds. - Pick single vs composite using the economic breakpoint above. - Confirm the product form — blanket for pipes and irregular shapes, board for flat equipment and walls. Product Forms Pyrogel-type performance is delivered in two main forms on this site: - Nano aerogel insulation blanket — flexible wrap for pipes, valves and complex geometry. - Nano insulation board — rigid panel for equipment casings and flat surfaces. For cryogenic service the same selection logic applies with the bottom row of the chart; our cryogenic pipe insulation guide covers system-level design. Related products: Nano Insulation Board, Nano Aerogel Insulation Blanket Related applications: Cement FAQ: Q: What thickness of pyrogel insulation do I need for a 300 °C pipe? A: For a DN100 pipe at 300 °C with a target surface temperature near 50 °C, plan on roughly 10–15 mm of pyrogel-type aerogel blanket. Larger pipes need slightly less per the thickness chart; add about 30 % in coastal or chemical CUI-risk zones. Q: How do I calculate pyrogel insulation thickness for a specific pipe? A: Use the cylindrical thermal-resistance formula R = ln((D+δ)/D) / (2πλ), solve for δ, then verify against the surface-temperature and energy-code limits. The chart in this guide is the fast approximation of that calculation. Q: Does pyrogel insulation need a vapor barrier in CUI areas? A: Usually not. Pyrogel-type aerogel blankets are hydrophobic (water uptake well below 1 %) and breathable, so moisture does not pool against the steel. An intact cladding plus the hydrophobic layer removes the main corrosion-under-insulation entry path. Q: Is single-layer or double-layer aerogel insulation more cost-effective? A: It depends on the aerogel-type share of total thickness. Above roughly 30 % at high temperature, 25 % at mid temperature and 20 % at low temperature, single-layer wins; below those breakpoints a composite with rock wool or calcium silicate is cheaper for the same resistance. Q: Can pyrogel-type aerogel be used for cryogenic service? A: Yes. The same selection logic applies below ambient — use the cryogenic row of the thickness chart (about 22–36 mm for pipes at –196 °C) and follow the system-level design in our cryogenic pipe insulation guide. ### Combined Cycle & Gas Turbine Power Plant Insulation: Materials & Spec URL: https://www.rosetexwool.net/news/combined-cycle-gas-turbine-power-plant-insulation/ 2026-09-01 | Author: Rosetexwool Editorial | Category: industry insight Summary: Spec guide for combined cycle power plant insulation — gas turbine exhaust, HRSG zone-by-zone materials, pipework thickness calculation, CUI protection, and vibration-zone installation. A combined cycle power plant (also called a CCGT plant or natural gas combined cycle plant) pairs a gas turbine with a heat recovery steam generator (HRSG) and a steam turbine. The gas turbine burns natural gas, the hot exhaust passes through the HRSG to make steam, and the steam turbine produces additional electricity. Insulation is not a finishing touch here — power plant thermal insulation is what decides the heat rate, the casing temperature the operator can touch, and whether the HRSG tubes fail early from corrosion. This guide to combined cycle power plant insulation walks through the specification for a modern combined cycle plant: which material belongs in each temperature zone, how to size pipework insulation for power plants, why corrosion under insulation (CUI) is the dominant reliability risk, and how to install insulation where vibration and thermal cycling are routine. Plant Layout and Temperature Zones A typical 400–800 MW combined cycle plant contains four distinct thermal zones, each with its own insulation requirement. Zone | Component | Operating temperature | Dominant constraint | 1 | Gas turbine combustor | 1600–1800 °C | Not user-insulated; ceramic thermal-barrier coating only | 2 | Gas turbine exhaust / diffuser | 600–700 °C | Lightweight, vibration-resistant lining | 3 | HRSG hot pass / superheater | 500–650 °C | Thermal-shock resistance, hot-face durability | 4 | HRSG economiser, ductwork, stack | 150–500 °C | CUI prevention, operator-touch safety | Insulation choice in zones 2–4 is what determines performance, fuel cost, and unplanned outage frequency. If you are sizing a new build or auditing an existing plant, work zone by zone. A single specification across the whole plant leads to over-specification in cool areas and under-specification at the hot face. For a broader view of insulation across the wider plant — boilers, substations, nuclear auxiliaries, offshore wind — see our guide to rock wool in the power industry and the application hub for power generation insulation. Gas Turbine Exhaust and Diffuser (600–700 °C) The gas turbine exhaust is the most demanding zone that the user actually insulates. Exhaust gas temperature (EGT) is normally 580–620 °C for modern F-class machines, rising to 650–700 °C on hot days or at full load. The exhaust flows through a diffuser and duct into the HRSG inlet, where every degree of heat loss is energy that never reaches the steam cycle. The exhaust diffuser is typically lined with light-weight refractory material — usually a ceramic fiber blanket or module behind a metallic casing. The fibre is chosen for three reasons: - Light weight — adds minimal load to the turbine skid and foundation. - Low thermal mass — survives frequent start-up and shutdown cycles without cracking. - Low thermal conductivity — even a thin layer captures most of the radiant heat in the diffuser. Material specification for this zone usually calls for alkaline-earth silicate fibre (AES) or standard aluminosilicate fibre blanket with a classification temperature of 1260 °C, density 96–128 kg/m³, and shot content below 15 %. The blanket is supported on stainless steel pins welded to the casing, with the cold face protected by a galvanised or aluminium jacket. For very high EGT or cyclic operation, specify higher alumina content fibre (60 % Al₂O₃) or a polycrystalline wool module for additional stability. Behind the diffuser, transition ductwork drops in temperature from ~600 °C at the HRSG inlet toward ~500 °C where the superheater tubes begin. This region is commonly insulated with rock wool blanket (operating cost is lower than ceramic fibre here) faced on the cold side with aluminium to prevent air infiltration. Where the duct passes through personnel-access areas, surface temperature must stay below 60 °C — calculate the required thickness from the duct surface temperature, not from a nominal hot-side number. HRSG High-Temperature Section (500–650 °C) The HRSG high-temperature section is the most material-intensive part of the plant. Hot flue gas leaves the gas turbine at 580–650 °C, passes over the superheater (typically 10–12 m of finned tubing) and reheater, then drops to 350–450 °C before entering the evaporator bank. At this temperature range, the dominant insulation choices are: - Ceramic fibre blanket or board (classification temperature 1260 °C, density 128–160 kg/m³) - High-purity ceramic fibre with 1260–1430 °C grade for cyclic service - Calcium silicate board as a structural backup layer where the casing needs to carry load The hot pass — the section directly above the superheater tubes — is the hardest region. Flue gas temperature here can swing by ±55 °C during load changes, and thermal cycling at every start-up and shutdown drives fatigue. Vacuum-formed ceramic fibre shapes or pre-fabricated modules are preferred because they keep joints closed even after thousands of cycles. For very tight geometries around tube bends, pre-formed ceramic fibre pipe sections reduce installation time and eliminate the gaps that lead to hot spots. Where the casing includes personnel access or walkways, multilayer construction is standard: 50 mm of ceramic fibre on the hot face for thermal resistance, backed with 50–80 mm of rock wool blanket or calcium silicate board for compressive strength and personnel protection. The cold-face layer is the one operators ever touch, so it must be sized for surface temperature, not for thermal loss. For the matching pipework, our calcium silicate pipe section is rated to 1000–1050 °C and gives a rigid, A1 non-combustible outer layer for the superheated-steam lines leaving this zone. HRSG Mid and Low-Temperature Sections (200–500 °C) Below the superheater, temperatures drop into the range where the insulation for power plants spec becomes more about corrosion prevention than thermal performance. The evaporator bank runs at 350–450 °C, the economiser at 200–300 °C, and the air-preheater / stack section at 150–200 °C. In this range, rock wool is the standard choice. Standard density 80–120 kg/m³ rock wool blanket, faced with aluminium or stainless steel cladding, gives a robust, repairable lining that meets personnel-protection surface-temperature limits at typical thicknesses of 80–120 mm. Calcium silicate board can be used where rigidity helps — for example on duct corners, equipment pads, or anywhere the lining needs to support cladding weight without sagging. CUI is the dominant failure mode in this zone. Flue gas carries water vapour, and the casing surface temperature often passes through the dew point during shutdown. Wet insulation in contact with carbon steel casing accelerates external corrosion. Mitigation is built into the specification: hydrophobic rock wool, sealed joints, drained cladding, and an air gap between insulation and casing where geometry allows. More on this in the CUI section below. Hot Pass and Ductwork (500–610 °C) The hot pass region of the HRSG — between the gas turbine outlet and the superheater — deserves special mention because the geometry is unforgiving. Tube bundles, support brackets, headers, and inspection ports create a complex three-dimensional shape. Insulation here must: - Wrap tightly around thousands of finned tubes without leaving exposed hot spots. - Tolerate thermal expansion of the tubes (several millimetres per cycle). - Resist vibration from flue gas pulsation. - Be removable for periodic tube inspection. Vacuum-formed ceramic fibre shapes, pre-fabricated modules, and ceramic fibre blanket with stainless steel wire mesh are the typical solutions. The specification usually calls for stitching the modules to stainless steel anchors welded to the casing, with ceramic fibre paper gaskets at every joint to absorb expansion. Density 160–192 kg/m³, classification 1260 °C, shot content under 12 %. Typical thickness in this zone is 100–150 mm. At those thicknesses, ceramic fibre modules become the most efficient install — they are made to drawing, dropped into position, and compressed 10–15 % against the casing to lock in place. Field cutting is minimised, joint quality is consistent, and the casing can be reassembled in the same configuration at every outage. Pipework Insulation Thickness Calculation Pipework thickness in a combined cycle plant is sized by one of three methods. Economic thickness method balances the capital cost of insulation against the present value of heat loss over the asset life. It applies to all heat-traced and untraced lines carrying hot fluids or steam. δ = √[(h₁ · ΔT) / ((k · ρ · c · ΔT) / (C · P · E · L))] where δ is economic insulation thickness, h₁ is the surface-to-air heat-transfer coefficient, ΔT is the temperature difference, k is thermal conductivity, ρ is density, c is specific heat, C is material cost per kilogramme, P is energy price, E is plant efficiency, and L is asset life. Surface-temperature method limits the outer cladding temperature to 60 °C in operator-access areas or to the dew point in unheated outdoor locations to prevent moisture condensation. Condensation-control method (also called the balance method) prevents condensation on chilled-water and cryogenic lines. It is less relevant for combined cycle steam lines but applies to air-preheater piping and condensate returns. For routine plant work the practical rules are: Service | Pipe size | Recommended insulation thickness | High-pressure steam (450 °C, 100 bar) | DN 100–300 | 80–120 mm ceramic fibre or rock wool | Medium-pressure steam (250–350 °C) | DN 80–200 | 60–80 mm rock wool | Hot water (150 °C) | DN 50–150 | 60–80 mm multilayer | Boiler feedwater (95–105 °C) | DN 50–200 | 40–60 mm rock wool or glass wool | Condensate (60–80 °C) | DN 50–150 | 40–50 mm glass wool | In coastal or high-humidity sites, increase these thicknesses by 10–15 % to keep the cold-face temperature above the dew point and reduce CUI risk. The extra cost is repaid many times over in avoided casing corrosion. A worked example for a typical HRSG high-pressure steam line (DN 150, 450 °C, ambient 25 °C, ceramic fibre with k = 0.04 W/m·K, density 180 kg/m³) gives δ ≈ 70 mm by the economic thickness method. In practice, the installed thickness is 80–100 mm because line geometry, supports, and valve bonnets require local increases to 120–150 mm. For pre-formed pipe sections, our rock wool pipe and calcium silicate pipe products cover the full DN 15 to DN 500 range with single-layer and multi-layer construction. Corrosion Under Insulation (CUI) CUI is the single largest cause of unplanned outages on insulated carbon-steel equipment in power plants. The mechanism is straightforward: water penetrates the insulation, reaches the casing surface, and stays there at 60–150 °C — the ideal temperature range for aqueous corrosion. The risk is highest on equipment that cycles through the dew point: economisers, feedwater heaters, air-preheater casings, and outdoor piping in seasonal climates. Failure modes include pitting, stress-corrosion cracking on austenitic stainless components, and through-wall perforation of carbon-steel casings. The economic cost is severe: a single casing replacement during an unplanned outage can exceed the entire lifetime savings from the insulation. CUI prevention is built into the specification in three places. Material selection. Use closed-cell or hydrophobic insulation where wetness is expected. Hydrophobic rock wool repels water but breathes; calcium silicate is dimensionally stable even when damp. For critical services — offshore platforms, coastal plants, equipment subject to wash-down — specify closed-cell products such as aerogel blanket or foam glass, both with hydrophobicity ≥ 98 %. Structural design. Maintain a 25–50 mm air gap between the casing and the insulation where geometry allows. Drain any condensation to the outside of the cladding. Use sealed lap joints on the cladding, not exposed butt joints. At flanges and valves, use removable insulation boxes that can be lifted for inspection without destroying the permanent lining. Inspection regime. CUI is invisible until it is too late. Specify removable insulation at flanges and inspection points, install tell-tale coupons on critical casings, and add visual inspection points every 5–10 m on long pipe runs. A 30-minute walk-down during a planned outage is far cheaper than a casing replacement. Insulation type | Hydrophobicity | Thermal conductivity @ 25 °C | Service life | Use case | Aerogel blanket | ≥ 98 % | ≤ 0.021 W/m·K | ≥ 10 years | Critical CUI zones, thin-layer retrofits | Foam glass | ≥ 98 % | 0.03–0.04 W/m·K | 15–20 years | Underground piping, cryogenic | Calcium silicate (dry service) | Moderate | 0.055–0.060 W/m·K | 20+ years | Steam piping, dry-service equipment | Rock wool (hydrophobic grade) | ≥ 98 % | 0.034–0.040 W/m·K | 15+ years | Boiler casings, general industrial | Vibration Zones Three regions in a combined cycle plant experience continuous or intermittent vibration that destroys ordinary insulation. Gas turbine exhaust diffuser. Combustion pulsation and thermal expansion drive structural vibration at low frequency but high amplitude. Aerogel blanket or compressed ceramic fibre board, mechanically fixed with stainless mesh and banded in place, is the typical specification. Adhesive-only fixing fails within months; mechanical fixing is mandatory. Steam pipe flanges and valve bonnets. Differential expansion between the pipe and its supports creates cyclic movement at every load change. Removable insulation boxes with inner metallic frames are the only durable solution. The box is held by quick-release straps so it can be lifted in minutes for inspection. Steam turbine inlet piping. High-velocity steam flow induces vibration in the insulation mass itself, leading to settlement, gaps, and hot spots above the pipe. Dense ceramic fibre board (≥ 192 kg/m³) anchored with welded pins is preferred; flexible blankets are unsuitable. At each of these zones the specification adds 10–15 % to the calculated insulation thickness to compensate for loss of effective coverage over time. Where this is done poorly — using the same nominal thickness as static zones — premature failure is the rule, not the exception. Case Studies from Operating Plants Delayed-coker retrofit at a major Chinese refinery. A steam line operating at 480 °C was insulated with 130 mm of alkaline-earth silicate fibre. Surface temperature was 16 °C above ambient and inspection revealed heavy external corrosion on the casing. The line was re-insulated with 70 mm of nanoporous aerogel blanket. Surface temperature dropped to 5 °C above ambient, heat loss fell by about 65 %, and the casing corrosion risk was eliminated by the closed-cell structure. Drying kiln in a chemical plant, northern China. A 30 m rotary kiln shell was running at 190 °C with a traditional mineral wool lining, losing more than 1 M RMB of gas per year per kiln. A 2–3 mm nanoporous aerogel coating replaced the original lining. Shell temperature dropped to 75 °C within hours of application, heat loss fell by 32 %, and the annual gas saving exceeded 0.9 M RMB per kiln. Payback time was less than 12 months. HRSG superheater header, 600 MW combined cycle plant. Field conditions: header at 540 °C, original insulation 130 mm of AES fibre, frequent cracking at inspection-port joints. The header was re-insulated with pre-formed ceramic fibre modules to drawing, density 192 kg/m³, classification 1260 °C. After two years of cyclic operation the modules showed no measurable settlement, hot spots at inspection ports were eliminated, and outage time for boiler inspection fell by 40 %. These are retrofit numbers from real plants. New builds should design for these gains from day one rather than capturing them later. Selection Checklist For an insulation specification on a new combined cycle plant, the following items belong on the datasheet: - Zone-by-zone temperature range (exhaust, hot pass, evaporator, economiser, stack). - Maximum continuous service temperature for each zone, including cyclic peaks. - Insulation type and form for each zone (blanket, board, module, pipe section). - Density, classification temperature, and shot content for ceramic fibre. - Hydrophobicity for any insulation exposed to outdoor or condensing service. - Outer cladding material and joint detail — aluminium, galvanised steel, or stainless steel. - Removable insulation at flanges, valves, and inspection points. - CUI mitigation — air gaps, drainage, sealed joints, inspection access. - Acoustic target for the diffuser and intake (typically 85 dBA at 1 m). - Surface temperature limit in operator-access zones (60 °C in most jurisdictions). The datasheet must be specific to the plant. A spec copied from another project — or from a generic supplier brochure — will fail in the field. Bottom Line Combined cycle and gas turbine power plant insulation is one of the highest-leverage decisions in plant design. Get it right and you keep the heat rate stable, avoid CUI-driven outages, and protect operators from hot surfaces. Get it wrong and you pay for it in fuel cost, maintenance, and unplanned shutdowns for the next 25 years. The specification follows a clear logic: material follows temperature, form follows geometry, density follows mechanical load, and cladding follows environment. Apply that logic in every zone, pay particular attention to CUI prevention and vibration-zone fixing, and the lining will outlast the plant. Rosewool has supplied rock wool pipe, calcium silicate pipe, ceramic fiber blanket and module products for combined cycle plants since 1982, with full ISO 9001, CE, and SGS certification. Contact our engineering team for zone-by-zone datasheets, pipe-thickness calculations, and CUI risk reviews for your specific plant. For detailed pipe-thickness tables on the boiler and steam side of a power plant, see our power plant insulation materials and thickness guide. Related products: Calcium Silicate Pipe, Ceramic Fiber Paper Related applications: Marine & Offshore FAQ: Q: What is combined cycle power plant insulation? A: Combined cycle power plant insulation is the thermal insulation applied to the gas turbine exhaust, the HRSG (heat recovery steam generator), steam piping, and ancillary equipment. Its role is to reduce heat loss, keep surface temperatures safe to touch, and prevent corrosion under insulation (CUI). Q: Which insulation material is used in the HRSG high-temperature section? A: The HRSG high-temperature section (500–650 °C) is insulated with ceramic fibre blanket, board, or pre-formed modules. Classification temperature is typically 1260 °C, with higher-purity grades (1430 °C or polycrystalline wool) used in cyclic or high-EGT service. Q: How thick should pipe insulation be in a combined cycle plant? A: As a working rule, high-pressure steam lines (450 °C, DN 100–300) need 80–120 mm of insulation, medium-pressure steam (250–350 °C) needs 60–80 mm, and hot water (150 °C) needs 60–80 mm. Economic thickness calculation is preferred for final sizing; the values above are field-typical starting points. Q: What is CUI and how is it prevented? A: Corrosion under insulation (CUI) is external corrosion of carbon-steel equipment caused by water trapped against the casing at 60–150 °C. It is prevented by using hydrophobic or closed-cell insulation, an air gap between casing and insulation, sealed cladding joints, drainage paths, and removable insulation at inspection points. Q: Why is aerogel blanket used in some combined cycle retrofits? A: Aerogel blanket has very low thermal conductivity (≤ 0.021 W/m·K at 25 °C) and closed-cell hydrophobic structure. In retrofits it lets designers cut insulation thickness by half while lowering surface temperature, and the closed-cell structure eliminates CUI risk on critical casings. Q: Which insulation material is used in vibration zones? A: Vibration zones — gas turbine exhaust diffuser, pipe flanges, steam turbine inlet piping — require dense ceramic fibre board (≥ 192 kg/m³) anchored with welded pins, or aerogel blanket banded in place with stainless mesh. Adhesive-only fixing is not durable in these regions. ### Offshore Fireproofing: Passive Fire Protection on Platforms URL: https://www.rosetexwool.net/news/offshore-fireproofing-passive-fire-protection-on-platforms/ 2026-09-01 | Author: Rosetexwool Editorial | Category: industry insight Summary: How offshore PFP (passive fire protection) is rated, where it goes on a platform, and what materials actually survive salt, vibration, and jet-fire heat load. Passive fire protection (PFP) is the part of an offshore platform that does nothing all year, then has to hold the steel together when a hydrocarbon fire breaks out. It is what keeps the escape route cold, the structural steel within its strength window, and the emergency shutdown valves working long enough for the crew to muster and the deluge system to open. Offshore fireproofing is not "fire insulation" in the usual building-services sense — it is engineered blast-, salt-, vibration- and jet-fire-resistant protection sized by rating curve and steel section factor. On fixed platforms, floaters, or FPSOs, PFP applies to topsides primary structure, pipe racks, drilling-area risers, and any member that can see a high-pressure hydrocarbon leak. For the broader thermal-insulation side of the same offshore asset — process-pipe heat retention, exhaust and turbine casing work — see our marine and offshore thermal insulation reference. This guide walks through the rating system, the zones that need protection, the materials that actually get specified (intumescent coating vs. fire blanket vs. flexible wrap), and the offshore-specific installation rules that decide whether a PFP system survives a North Sea winter or a warm-water splash zone. The Rating System: H-60, H-120, J-60, J-120 Offshore PFP is specified against two fire curves and two time tiers, giving four rating combinations that turn up in nearly every project specification: Rating | Fire curve | Time | Where it is used | H-60 | Hydrocarbon, ISO 834 | 60 min | Process pipe racks, vessel skirts, secondary structure | H-120 | Hydrocarbon, ISO 834 | 120 min | Compressor decks, large hydrocarbon storage, primary escape-route steel | J-60 | Jet fire, UL 1709 | 60 min | High-pressure hydrocarbon valves, manifolds, hazardous-area pipework | J-120 | Jet fire, UL 1709 | 120 min | Drilling-module risers, wellhead areas, high-consequence jet-fire zones | The core standard is ISO 13702:2024 (fire and explosion control on offshore production installations), with GB/T 20660-2020 covering the equivalent Chinese offshore requirements and API RP 14G supporting the original risk-based design logic. The rating an engineer picks is driven by the section factor of the steel (Hp/A, the heated perimeter divided by cross-sectional area): thinner steel sections heat faster and therefore need more PFP thickness for the same rating. Jet fire is the curve that catches projects off guard. A UL 1709 cell-fire reaches about 1093 °C inside five minutes and delivers roughly 204 kW/m² of incident radiant heat — an order of magnitude beyond what a passive building-services fire rating assumes. Anything that can see a high-pressure leak (ESDV manifolds, blowdown valves, riser isolation) needs J-rating, not H-rating. For the rating-vs-spec layer where PFP meets thermal insulation on risers and process pipework, the A-60 marine insulation guide goes into the bulk heat-balance and casing-temperature side; PFP is the other half of that same wall. For the shipboard side of the same subject — A-class divisions, fire-rated bulkheads and accommodation boundaries — our marine fire insulation guide covers the SOLAS material rules in detail. Where the PFP Goes: Zone-by-Zone Layout A typical offshore platform is divided into PFP zones that line up with — but are not identical to — the process modules and the fire zones. The same fire compartment can carry different PFP ratings on different members depending on what that member does during a fire: - Living-quarter façade facing process — A-rated walls and claddings with PFP on the structural columns and beams of the LQ side. This is also where blast load is layered on top of fire load, so the PFP must be blast-tolerant as well as fire-stable. - Process module primary structure — H-120 on legs and primary beams, H-60 on secondary beams and grating supports. Compressor and pump skids are usually H-120 around the casing, dropping to H-60 on the supporting steelwork. - Pipe racks and ESD valve manifolds — J-60 around the valves and the first 450–500 mm of connecting pipe, dropping to H-60 along the rest of the run. This is the typical "shoulder" transition where engineers get caught using one rating across the whole line. - Drilling and wellhead areas — J-120 on the BOP stack supports, the riser isolation valves, and any structural member within sight of a high-pressure release. - Escape routes — TEMPSC stations, lifeboat embarkation, refuge areas — H-120 on the supporting steel of the muster deck, the route down to the boat deck, and any walkway that is on the only available evacuation path. - Helideck supporting structure — H-60 minimum, often H-120 on primary columns, designed to keep the deck load-bearing under crash-fire fuel-pooling scenarios. Where a process module also carries thermal insulation for heat-rate or anti-condensation reasons — for example the casing of a gas-turbine exhaust or HRSG section piped back to a platform — the combined cycle power plant insulation spec covers the bulk thermal side, and the PFP brings the rating side. The two layers stack on the same steel and must be chemically compatible. Anti-condensation thickness on those lines is calculated from dew point rather than from a fire curve, and the same applies to accommodation acoustics and LNG cold service — our non-fire marine insulation thickness and acoustic targets guide gives the calculation and the tables. Materials: What Actually Goes on the Steel Three PFP families compete for offshore specification. Each has a real niche, none is a universal substitute. Intumescent epoxy fireproofing A two- or three-coat epoxy system that swells into a protective char when heated. It is the default for offshore process modules because it: - Adds the lowest dead-weight per rating point (typically 5–15 mm for H-60, 15–25 mm for H-120 on heavy sections). - Tolerates salt spray when correctly applied over a compatible primer. - Holds blast overpressure up to roughly 1.0 bar without spalling, which matters on living-quarter faces and primary process structure. - Is spray-applied, so it follows complex geometry (valves, brackets, cable-tray penetrations) without joints. Limitations: solvent-borne systems need controlled application conditions; some epoxy intumescents cannot be immersed and must be top-coated in the splash zone. PFP thickness on intumescent coating is calibrated to the section factor — a heavy column will need substantially less coating than a thin hollow brace for the same rating. Modular fire blanket / wrap systems A factory-made blanket of high-temperature fibre (high-alumina or polycrystalline wool, typically 64–128 kg/m³) encapsulated in a foil or glass-cloth facing, supplied as discrete pads, half-shells, or pillow modules that are mechanically banded onto the steel. Used where: - The geometry is too complex for spray application. - Rapid installation on a brownfield project matters (modules go on without surface prep beyond cleaning). - A removable / re-enterable system is needed for inspection of the protected steel. Thickness is selected to hit the rating curve on the section factor; expect 25–75 mm of total blanket for H-60 to H-120 on heavy structural sections. The facing must be sealed at top and bottom of vertical members — unsealed seams are the most common cause of moisture ingress and corrosion under the blanket. Rigid fire-board systems Calcium-silicate board, high-density rock-wool board, or composite boarding used for firewalls, blast walls, escape-route enclosures, and the LQ-facing-process wall. These are mechanically fixed rather than spray-applied. The boards are heavy (calcium silicate at ~200–230 kg/m³), which limits use on elevated decks, but they give a robust, low-water-permeability surface that is easy to inspect and to repair locally. For most platform PFP projects the specification combines all three: intumescent coating on the structural steel, modular blankets on complex pipework and valve manifolds, calcium-silicate or high-density rock wool blanket board on firewalls and escape-route enclosures. Radiant Heat and Jet-Fire Shielding For J-rated zones, the PFP has to defeat a thermal load that does not exist in building-services work. A UL 1709 jet fire reaches 1093 °C in five minutes and 1100+ °C sustained; the incident heat flux on a structure 5–10 m from the leak point is on the order of 100–200 kW/m². Two design strategies are routine: - Thickness selection on section factor. For a given rating the relationship between fire-resistance thickness and Hp/A is published by the PFP manufacturer in the form of design tables. Engineers pick the steel section, read off the required thickness for J-60 or J-120, and add a corrosion / wastage allowance. The reason jet-fire PFP looks "thick" is mostly that — J-ratings require substantially more material than H-ratings on the same member. - Shielding away from the source. Wrapping the first 450–500 mm of pipe leaving a high-pressure valve in a J-rated blanket, while leaving the rest of the line on H-60, produces a workable design without overcoating the whole pipe rack. This is the design philosophy behind ASTM E 1725-tested cable-tray protection, and the same logic applies to instrument tubing and small-bore impulse lines. CFD fire modelling (FLACS-Fire and equivalent) is now the standard way to confirm that a proposed layout meets ALARP — putting PFP only where the radiant heat map says it is required, instead of coating whole modules out of conservatism. The risk of over-application is real: every extra kilogram of PFP adds to topside weight and to blast design load. Where the heat load is also a heat-recovery opportunity — for example the casing of a gas turbine or a waste-heat boiler piped back to the platform — the engineering logic overlaps with offshore thermal insulation work in the power module. The same wall often has to perform both duties. Offshore-Specific Installation Considerations A PFP system that passes a 60-minute jet-fire test in a lab can still fail on platform if the offshore environment is ignored. Four factors dominate: - Salt spray and splash-zone exposure. The transition between atmospheric zone and splash zone is where most coating-based PFP systems fail. The fix is a primer-and-topcoat system from the same manufacturer as the intumescent, with documented compatibility. For blanket systems the fix is full banding of seams and a topcoat that resists UV and salt. Periodic visual inspection — typically annual, with closer review after storms — is mandatory under most classification society rules. - Vibration and mechanical shock. Continuous running of gas turbines, compressors, and drilling equipment vibrates the supporting steel in a 5–50 Hz band. Rigid cementitious PFPs crack; flexible blankets and elastomeric-intumescent coatings survive. Cable penetrations and pipe clamps are the usual failure points. - Weather windows. Offshore spray-applied PFP needs dry steel, controlled humidity, and a window without rain or sea-spray deposition for the full cure of the primer and the intumescent base coat. Logistics around weather windows are often the real schedule driver on offshore PFP projects — coating chemistry is the easy part. - Maintenance access. Anything that needs inspection (manifolds, ESD valves, cable joints) must be re-enterable. Bolted-on blanket pillows, removable calcium-silicate panels, and banded modular wraps are designed for this. Sprayed-on intumescent has to be cut and patched. The installation contractor should hold the manufacturer PFP-application certification, and the field quality plan should record section-factor verification, dry-film thickness on every member, and seam-banding continuity on blanket systems. Selection Checklist A short checklist used by most offshore PFP engineers at spec stage: - Rating for each member: H-60 / H-120 / J-60 / J-120, driven by fire-zone map and ESD valve schedule. - Section factor Hp/A for each member type — drives thickness on intumescent, blanket, and board. - Material family for each zone: intumescent coating, modular blanket / wrap, calcium-silicate or rock-wool board. - Splash-zone treatment at every member crossing the atmospheric / splash boundary. - Blast tolerance on LQ-facing-process steel and primary process columns (1.0 bar minimum). - Cable-tray and small-bore-line shielding length: 450–500 mm from the source valve. - Inspection / re-entry strategy for ESD valves, cable joints, and instrument tubing. - Compatible primer and topcoat supplied by a single PFP manufacturer, not mixed. - Field quality plan: DFT logging, seam-banding photos, third-party inspection at handover. Rosewool supplies modular ceramic fiber blanket and calcium silicate insulation board used in offshore PFP and firewall applications, together with rock-wool and calcium-silicate pipe and board systems for platform process pipework. For offshore fireproofing questions, zone layouts, or thickness calculations tied to your specific fire-zone map, contact our engineering team with your PFP rating schedule and section-factor list. Related products: Ceramic Fiber Rope, Calcium Silicate Pipe Related applications: Marine & Offshore FAQ: Q: What is the difference between H-rating and J-rating offshore? A: H-rating uses the slower ISO 834 hydrocarbon curve and covers general process pipe racks, vessel skirts, secondary steelwork, and escape-route structures. J-rating uses the much faster UL 1709 jet-fire curve and applies to anything that can see a high-pressure hydrocarbon leak — ESD valves, wellhead areas, drilling risers. J-rating typically requires substantially thicker PFP than H-rating on the same member. Q: How long does offshore PFP need to last in a fire? A: Most offshore PFP is rated for either 60 minutes (H-60, J-60) or 120 minutes (H-120, J-120). The specifier chooses based on fire-zone consequence, evacuation time, and structural redundancy. H-120 and J-120 are used on primary process structure, escape-route steel, and high-consequence jet-fire zones; H-60 and J-60 cover secondary pipe racks and less critical members. Q: Can normal thermal insulation act as PFP offshore? A: No. PFP has to be rated against a fire curve (ISO 834 or UL 1709) on a defined steel section factor. Standard process insulation such as rock wool or calcium silicate improves the casing temperature but is not tested as a fire rating. Offshore practice is to combine the two: a thermal-insulation layer sized for heat-rate or anti-condensation, with a separate PFP layer sized for the fire rating — sometimes as one composite system, sometimes as two independent systems on the same steel. Q: What is the most common offshore PFP failure? A: Moisture and salt-spray ingress under the PFP — usually at the unsealed seam of a modular blanket, the cut edge of an applied board, or a damaged intumescent topcoat in the splash zone. The corrosion then proceeds unseen and only surfaces during a scheduled inspection or, worse, during a fire. The second most common is mismatched primer and intumescent from different manufacturers, leading to delamination. Q: Does intumescent coating or fire blanket work better offshore? A: It depends on the geometry and access. Intumescent epoxy is lighter, follows complex shapes well, and is the default for process-module steel. Modular fire blankets win on complex pipework, valve manifolds, and any member that needs to be re-entered for inspection. Most platforms use both — intumescent on the structural steel, blankets on the valve and pipe-work details. Q: What standards govern offshore passive fire protection? A: ISO 13702:2024 is the primary international standard for fire and explosion control on offshore production installations, including PFP zoning and rating logic. GB/T 20660-2020 is the equivalent Chinese offshore standard. API RP 14G supports risk-based design language. UL 1709 governs jet-fire testing, ISO 834 governs the hydrocarbon curve, and ASTM E 1725 governs cable-tray fire protection. ### High-Temperature Insulation Wool: Temperature Ratings & How to Choose URL: https://www.rosetexwool.net/news/high-temperature-insulation-wool-temperature-ratings/ 2026-08-31 | Author: Rosetexwool Editorial | Category: industry insight Summary: Choose the right high-temperature insulation wool: glass wool, rock wool, ceramic fiber, or polycrystalline wool. Compare temperature ratings, purity, and environmental suitability. The phrase "high-temperature insulation wool" covers four very different material families. Picking the wrong one for the temperature or environment is one of the most common causes of lining failure, energy loss, and unplanned downtime. This guide places each wool type on a temperature ladder, explains how purity and impurities affect performance, and gives a practical selection method based on temperature plus operating environment. The Four Temperature Tiers of Insulation Wool Industrial insulation wools are grouped by their maximum continuous service temperature and chemistry. The four tiers are: Tier | Material | Continuous service temp | Fire classification | Typical form | 1 | Glass wool | ≤300–350 °C | A1 non-combustible | Blanket, board, pipe section | 2 | Rock wool (stone wool) | ≤650–750 °C | A1 non-combustible | Blanket, board, pipe, loose | 3 | Ceramic fiber (aluminosilicate wool) | ≤1000–1300 °C | A1 non-combustible | Blanket, board, module, paper, bulk | 4 | Polycrystalline wool | ≤1400–1500 °C | A1 non-combustible | Blanket, board, module | Each step up the ladder increases temperature capability and usually cost. The goal is to match the material to the actual continuous operating temperature, not to overspecify. Tier 1 — Glass wool Glass wool is made from recycled glass and silica sand. It is the lightest and lowest-cost industrial wool, with excellent thermal and acoustic performance at moderate temperatures. It is widely used in HVAC ductwork, building services, and process piping below 300 °C. Above 350 °C, glass wool begins to soften and lose fibre structure. It is not suitable for furnaces, high-temperature kilns, or fire barriers. If you are specifying a lining rather than a wool, our heat-resistant materials for furnace guide ranks every option by temperature tier. For rock wool temperature limits, see what temperature can rock wool withstand. For the rigid board form of glass wool itself — density classes, lambda at 25 °C and 70 °C, compressive strength and facings — see glass wool insulation board: rigid board selection & spec. Tier 2 — Rock wool Rock wool is spun from molten basalt or diabase rock. It handles roughly double the temperature of glass wool and offers higher density and compressive strength. Rock wool is the standard choice for industrial pipe insulation, boiler casings, fire-rated walls, and marine A-60 divisions. Rosewool supplies rock wool blanket, rock wool board, and rock wool pipe sections for these applications. Tier 3 — Ceramic fiber Ceramic fiber — also called aluminosilicate wool or refractory ceramic fiber — is produced by melting alumina and silica and spinning the melt into fine fibres. It is lightweight, flexible, and stable to 1000–1300 °C depending on grade. Standard, high-purity, high-alumina, and zirconia grades cover the range from 1050 °C to 1430 °C classification temperature. Common products include ceramic fiber blanket and ceramic fiber board. The same fiber is also supplied loose as bulk for cavity fill and joint packing; grade selection, installed density, and conversion routes are set out in our ceramic fiber bulk guide. Tier 4 — Polycrystalline wool Polycrystalline wool is made by sol-gel processing and controlled crystallisation. The fibres contain mullite or alpha-alumina crystals rather than a glassy structure. This gives the highest temperature rating and the lowest high-temperature shrinkage. It is used in furnaces, kilns, and processes that run continuously above 1300 °C. For ultra-high-temperature boards, see polycrystalline mullite fiberboard. Our polycrystalline mullite fiber board guide covers grade selection, shrinkage data at 1500-1600 °C, and where the board outperforms standard ceramic fiber. For the fiber tier above polycrystalline wool — AZS and yttria-stabilized zirconia — see our guide to alumina zirconia ultra-high-temperature fiber. Why Purity and Impurities Matter The performance of any high-temperature wool depends heavily on chemical purity. Impurities such as iron oxide, sodium oxide, and potassium oxide form low-melting phases that accelerate shrinkage, raise thermal conductivity, and shorten lining life. Alumina content drives temperature ceiling For ceramic fibres, higher alumina content generally means higher temperature capability: - Standard ceramic fibre: ~43–47 % Al₂O₃, service up to ~1050 °C - High-alumina ceramic fibre: ~55–60 % Al₂O₃, service up to ~1200 °C - Zirconia ceramic fibre: ~39 % Al₂O₃ + 15–17 % ZrO₂, service up to ~1300 °C - Polycrystalline wool: 70–95 % Al₂O₃, service up to ~1400–1500 °C Impurities to control Impurity | Effect at high temperature | Fe₂O₃ | Forms conductive phases; increases thermal conductivity and shrinkage | Na₂O + K₂O | Creates low-melting glass phases; reduces temperature ceiling | CaO + MgO | Can react with sulphur-bearing gases in corrosive environments | Cr₂O₃ | Can destabilise alumina grain boundaries in some polycrystalline fibres | For critical applications, request a chemical analysis and compare it against the supplier's datasheet. A low price is not a bargain if the impurity level shortens the lining life. Selection Guide: Temperature + Environment Use the following matrix to narrow the choice. Continuous temp | Dry / clean | Moist / corrosive | High mechanical load | Rapid thermal cycling | ≤350 °C | Glass wool | Glass wool + facing, or rock wool | Rock wool | Glass wool or rock wool | 350–750 °C | Rock wool | Rock wool + facing | Rock wool | Ceramic fiber | 750–1100 °C | Ceramic fiber | Ceramic fiber + coating | Dense ceramic fiber board | Ceramic fiber module | 1100–1300 °C | High-alumina or zirconia ceramic fiber | Zirconia ceramic fiber | Zirconia or PCW board | Polycrystalline wool | 1300–1500 °C | Polycrystalline wool | Polycrystalline wool + barrier | Polycrystalline wool board | Polycrystalline wool | Temperature is the first filter Always start with the maximum continuous operating temperature, including upset conditions. The classification temperature printed on the datasheet is not the service temperature. For example, a ceramic fibre classified at 1260 °C is usually suitable for only about 1050–1100 °C continuous use. Environment is the second filter - Moisture — glass wool and standard ceramic fibre absorb water; use faced products or choose rock wool / hydrophobic grades. - Sulphur or acid gases — high CaO/MgO rock wool can degrade; choose low-alkali ceramic fibre or protective coatings. - High mechanical load — use rigid board rather than blanket; consider rock wool or dense ceramic fibre board. - Thermal cycling — flexible blankets and modules tolerate expansion better than rigid boards. - Modules above 1400 °C — standard ceramic-fiber modules soften and shrink at the hot face; switch to polycrystalline fiber modules when the lining must run 1400–1700 °C. Common Misuse Cases Using glass wool above its limit Glass wool is sometimes installed on equipment that reaches 400–500 °C because it is cheap and easy to handle. Above 350 °C the fibres soften and mat together, the thermal conductivity rises sharply, and the insulation layer collapses. The fix is to switch to rock wool or ceramic fibre. Confusing classification temperature with service temperature A fibre rated at 1260 °C is not intended for 1260 °C continuous operation. Service temperature is usually 100–200 °C below classification temperature. Running standard ceramic fibre at 1300 °C continuous causes rapid shrinkage and powdering. Ignoring corrosion in flue gas In sulphur-bearing flue gases, alkaline impurities in the fibre react to form sulphates. This is why some boiler and heater linings fail prematurely even though the temperature was within range. Specify low-alkali grades or add a protective coating. Poor installation practice Even the right material fails if it is compressed too tightly, left exposed to airflow, or fixed with the wrong anchors. Ceramic fibre modules need correct compression and spacing; rock wool pipe sections need proper cladding; and all high-temperature linings need expansion joints. For a broader view of material options, see our guide to the top 10 high-temperature insulation materials. Bottom Line High-temperature insulation wool is not one material. It is a family of materials defined by temperature capability, chemistry, and form. The selection process is simple in principle: define the continuous operating temperature, identify the environmental stresses, choose the lowest tier that safely handles both, and verify purity against the application requirements. Glass wool wins on cost and acoustics below 350 °C. Rock wool covers the 350–750 °C range with strength and fire resistance. Ceramic fibre handles 750–1300 °C with low mass and flexibility. Polycrystalline wool takes over above 1300 °C where shrinkage and stability become critical. At Rosewool we supply the full range: glass wool, rock wool, ceramic fiber, and polycrystalline mullite fiberboard. For a graded furnace lining design that places alumina at the hot face and AES in the backup, see Alumina & AES in ultra-high-temperature furnaces. Contact our technical team for grade selection and thickness calculations based on your process conditions. Related products: Refractory Ceramic Fiber Blanket — Ceramic Fiber Blanket Insulation, Rockwool Insulation Blanket (Rock Wool Blanket), Glass Wool Board Related applications: Aerospace & Defense, Building FAQ: Q: What is high-temperature insulation wool? A: High-temperature insulation wool is a group of fibrous insulation materials that includes glass wool, rock wool, ceramic fiber, and polycrystalline wool. They are used at progressively higher temperatures, from about 350 °C up to 1500 °C. Q: What are the temperature ratings of insulation wool? A: Glass wool is rated up to about 300–350 °C continuous, rock wool up to 650–750 °C, ceramic fiber up to 1000–1300 °C depending on grade, and polycrystalline wool up to about 1400–1500 °C. Q: Is rock wool or ceramic fiber better for high temperature? A: Rock wool is better for 350–750 °C applications that need strength, load-bearing, or fire barriers. Ceramic fiber is better for 750–1300 °C applications that need low mass, flexibility, and rapid thermal cycling. Q: Why does purity matter in refractory wool? A: Impurities such as iron oxide, sodium oxide, and potassium oxide form low-melting phases that increase shrinkage and thermal conductivity. Higher-purity fibres, especially high-alumina or polycrystalline wool, last longer at high temperature. Q: What happens if insulation wool is used above its temperature rating? A: Above its rated temperature, the fibres soften, shrink, sinter, or powder. The insulation layer loses thickness and thermal performance, hot spots form, and the lining must be replaced sooner than planned. ### Polycrystalline Wool Fiber vs Standard Ceramic Fiber: What's Different? URL: https://www.rosetexwool.net/news/polycrystalline-wool-fiber-vs-standard-ceramic-fiber/ 2026-08-31 | Author: Rosetexwool Editorial | Category: industry insight Summary: Compare polycrystalline wool fiber and standard ceramic fiber: crystal structure, temperature ratings, shrinkage, thermal shock, cost, and when to upgrade to polycrystalline insulation. Polycrystalline wool fiber and standard ceramic fiber look similar on the shelf. Both are white, lightweight, high-temperature insulation wools. But the difference in crystal structure changes almost everything that matters in service: temperature limit, shrinkage, thermal conductivity, and lifespan. This guide compares polycrystalline wool fiber with standard aluminosilicate ceramic fiber from a materials and purchasing perspective. If you are deciding whether the extra cost of polycrystalline wool is justified for your furnace or kiln, start here. What the Names Mean Standard ceramic fiber is the general name for amorphous aluminosilicate wool — the material most people picture when they hear "ceramic fiber blanket." It is made by melting alumina and silica together and spinning or blowing the melt into fibers. Common grades are classified at 1260 °C, 1400 °C, and 1430 °C depending on alumina content and zirconia additions. Polycrystalline wool fiber is a higher-grade refractory fiber made by sol-gel and controlled crystallisation. Instead of a glassy structure, the fibers contain crystalline phases such as mullite or alpha-alumina. This gives the material a higher use temperature and much lower high-temperature shrinkage. For an ultra-high-temperature board option, see our polycrystalline mullite fiberboard product page. For 1900 °C application guidance, read our guide on polycrystalline mullite boards for ultra-high temperature. Composition and Crystal Structure The core difference is the atomic arrangement. Property | Standard ceramic fiber | Polycrystalline wool fiber | Chemistry | Al₂O₃ + SiO₂ glass | Al₂O₃-rich or mullite crystalline structure | Typical Al₂O₃ | 43–55 % | 70–95 % | Structure | Amorphous (glass) | Polycrystalline | Fiber diameter | 2–5 µm | 3–7 µm | Classification temp | 1260–1430 °C | 1600–1800 °C | Standard ceramic fiber is a frozen liquid. The atoms are arranged randomly, like glass. That makes it flexible and easy to manufacture, but the structure starts to reorganise and shrink above about 1000–1100 °C. Polycrystalline wool fiber is already crystalline. The grains are locked in place, so the fiber stays dimensionally stable at far higher temperatures. How They Are Made Standard ceramic fiber Standard ceramic fiber is produced by melting a mixture of alumina, silica, and sometimes zirconia in an electric arc furnace at around 1800–2000 °C. The molten stream is blown or spun into fibers, then collected as bulk, blanket, board, paper, or module. The process is fast and energy-efficient, which is why standard ceramic fiber is inexpensive. Polycrystalline wool fiber Polycrystalline wool fiber is made by sol-gel chemistry. An aluminium-rich solution is prepared, spun into gel fibers, dried, and then heat-treated at high temperature to crystallise the structure. The process is slower, requires purer raw materials, and uses more energy. That is the main reason polycrystalline wool costs several times more than standard ceramic fiber. Temperature Ratings and Shrinkage Temperature performance is where the difference becomes visible. Property | Standard ceramic fiber (1260 grade) | Polycrystalline wool fiber | Classification temperature | 1260 °C | 1600–1800 °C | Continuous use temperature | ~1000–1100 °C | ~1400–1500 °C | Linear shrinkage at 24 h | 3–5 % at 1260 °C | <1–2 % at 1400 °C | Maximum practical limit | ~1200 °C short term | ~1600 °C short term | The numbers matter for furnace design. A lining rated for 1260 °C classification temperature may only be suitable for 1050 °C continuous operation because of shrinkage and embrittlement. Polycrystalline wool fiber is the next step up when continuous operating temperatures move into the 1300–1500 °C range. Thermal Conductivity and Thermal Shock Thermal conductivity rises with temperature for both materials, but the curves diverge at very high temperature. Temperature | Standard ceramic fiber (1260 grade) | Polycrystalline wool fiber | 400 °C | ~0.09–0.13 W/m·K | ~0.08–0.12 W/m·K | 800 °C | ~0.17–0.23 W/m·K | ~0.13–0.18 W/m·K | 1200 °C | ~0.28–0.35 W/m·K | ~0.18–0.25 W/m·K | At 1200 °C and above, polycrystalline wool fiber retains better insulating value. The lower conductivity becomes important in fuel-fired furnaces and kilns where heat loss directly affects operating cost. Thermal shock resistance is also different. Standard ceramic fiber is generally more flexible and forgiving in cyclic applications because the glassy structure can absorb some strain. Polycrystalline fiber is stiffer. In very rapid thermal cycling, fiber modules may need a different anchoring or compression design, but the material itself resists shrinkage damage far better. Cost Curve: When Is Polycrystalline Wool Worth It? Polycrystalline wool fiber is more expensive than standard ceramic fiber — often several times the price per kilogram. The upgrade pays off when one or more of the following conditions apply: - Continuous operating temperature is above 1200 °C. Standard fiber shrinks too much and loses insulation value. - Furnace uptime is critical. Less shrinkage means longer lining life and fewer rebuilds. - Energy cost is high. Lower thermal conductivity at 1200–1400 °C reduces fuel consumption. - Product contamination must be minimised. Higher purity and lower alkali content reduce contamination risk in glass, ceramics, and metals. - Process temperature is close to the limit. Running 1260-grade fiber at 1200 °C continuous leaves no margin; polycrystalline fiber provides a safety buffer. For temperatures below 1100 °C, standard ceramic fiber is usually the better economic choice. The performance gain from polycrystalline wool is small, and the cost increase is significant. Application Guide by Temperature and Industry Use the following guidance to narrow the choice. Continuous temperature | Recommended fiber | Typical applications | ≤1100 °C | Standard ceramic fiber (1260 grade) | General furnaces, kilns, boilers, petrochemical heaters | 1100–1300 °C | High-alumina or zirconia ceramic fiber | Steel reheating, aluminium holding, glass forehearths | 1300–1500 °C | Polycrystalline wool fiber | High-temperature kilns, diffusion furnaces, crystal growth, ceramic sintering | >1500 °C | Polycrystalline wool fiber or oxide board | Specialty ceramics, aerospace testing, research furnaces | Steel and non-ferrous metals Reheating furnaces and ladle covers in steelmaking often operate at 1200–1300 °C. At the lower end of this range, high-alumina ceramic fiber works. At the upper end or in areas with severe chemical attack, polycrystalline wool fiber is preferred. Glass and ceramics Glass melting and ceramic sintering demand clean, stable linings. Polycrystalline wool fiber is used where purity and low shrinkage justify the cost, especially in continuous production lines where downtime is expensive. Electronics and solar Diffusion furnaces, crystal pullers, and sintering equipment for battery materials and photovoltaic wafers often run at 1300–1500 °C. Polycrystalline fiber is the standard choice in these applications because of its cleanliness and temperature stability. Handling, Health, and Installation Notes Both materials are respirable fiber products and should be handled with appropriate personal protective equipment. Both are classified as articles under most regulatory frameworks when installed, but loose fiber and cutting dust require control measures. Polycrystalline wool fiber is slightly stiffer than standard ceramic fiber. This makes it less forgiving around tight curves, but it machines cleanly and holds shape well in modules and boards. For details on how these modules are built, anchored, and installed, see our guide to polycrystalline fiber modules: spec, installation and applications. Common Mistakes When Specifying - Confusing classification temperature with service temperature. A 1260 °C classification fiber is not designed for 1260 °C continuous use. - Upgrading unnecessarily. Below 1100 °C, the premium for polycrystalline wool rarely pays back. - Ignoring shrinkage. In a 50 mm lining, 4 % shrinkage creates a 2 mm gap and hot spots. At 1400 °C, standard fiber shrinks much more than polycrystalline fiber. - Forgetting the backup layer. A polycrystalline hot face is often backed by standard fiber or rock wool to reduce total cost while keeping the hot-zone performance. For a broader overview of high-temperature options, see our guide to the top 10 high-temperature insulation materials. Bottom Line Polycrystalline wool fiber and standard ceramic fiber serve different temperature regimes. Standard ceramic fiber is the workhorse for furnaces up to about 1100 °C continuous. Polycrystalline wool fiber takes over when continuous temperatures climb above 1200–1300 °C, where shrinkage, conductivity, and lining life become critical. For service beyond the PCW range into the 1500–1700 °C band and above, the selection moves to alumina zirconia ultra-high-temperature fiber. The decision is not about which material is "better." It is about matching the fiber to the temperature, thermal cycling, uptime requirement, and energy cost of the process. At Rosewool we supply both standard ceramic fiber products and polycrystalline mullite fiberboard for high-temperature industrial applications. See how these materials fit into complete furnace systems in our guide to Alumina & AES in high-temperature furnace insulation. Contact our technical team for help selecting the right fiber grade and lining design for your furnace or kiln. For supplier qualification and a buyer's checklist, see our polycrystalline fiber module supplier selection guide. For a dedicated manufacturer and supplier evaluation guide, see our standard refractory ceramic fiber manufacturer guide. Related products: Ceramic Fiber Cloth, Ceramic Fiber Modules, Glass Wool Blanket Related applications: Cement, Environmental & Dust Removal FAQ: Q: What is the difference between polycrystalline wool fiber and standard ceramic fiber? A: Standard ceramic fiber is an amorphous aluminosilicate glass fiber, usually classified at 1260–1430 °C. Polycrystalline wool fiber is made by sol-gel and crystallisation, giving it a crystalline mullite or alumina structure and a higher continuous use temperature of about 1400–1500 °C. Q: What is polycrystalline wool used for? A: Polycrystalline wool fiber is used in high-temperature furnaces, kilns, diffusion furnaces, crystal growth equipment, and ceramic sintering processes where continuous temperatures exceed 1200–1300 °C and low shrinkage is required. Q: Is polycrystalline wool fiber better than ceramic fiber? A: It depends on temperature. Above about 1200 °C continuous, polycrystalline wool fiber has lower shrinkage, better thermal stability, and lower thermal conductivity. Below 1100 °C, standard ceramic fiber is usually more cost-effective and performs well. Q: What is the maximum temperature for polycrystalline wool fiber? A: Polycrystalline wool fiber is typically classified at 1600–1800 °C and can be used continuously at approximately 1400–1500 °C, depending on grade and atmosphere. Short-term exposure can reach 1600 °C. Q: Why does polycrystalline wool fiber cost more than ceramic fiber? A: Polycrystalline wool fiber is made by a sol-gel process that requires high-purity alumina raw materials and controlled high-temperature crystallisation. The process is slower and more energy-intensive than melting and spinning standard ceramic fiber. Q: When should I upgrade from standard ceramic fiber to polycrystalline wool fiber? A: Upgrade when continuous operating temperature is above 1200 °C, when shrinkage and lining life are critical, when energy costs are high, or when product contamination from impurities must be minimised. ### Is Wool Fire Resistant? Sheep Wool vs Mineral Wool Fire Performance URL: https://www.rosetexwool.net/news/is-wool-fire-resistant-sheep-wool-vs-mineral-wool/ 2026-08-30 | Author: Rosetexwool Editorial | Category: industry insight Summary: Sheep wool is naturally flame-resistant, but it is not non-combustible. Compare wool and mineral wool fire performance, ignition temperature, smoke, and where each belongs. Search the term "wool fire resistant" and you will find two very different conversations. One is about sheep wool as a natural, breathable building insulation. The other is about mineral wool — rock wool and glass wool — used in industrial high-temperature insulation. They are both called "wool," but their fire behaviour is fundamentally different. This article clarifies whether wool is fire resistant, how sheep wool compares with mineral wool, and why industrial heat applications must use mineral wool regardless of how well sheep wool performs in a home insulation test. Is Sheep Wool Fire Resistant? Yes — sheep wool is naturally flame resistant, but it is not non-combustible. Sheep wool resists ignition because of its chemistry. Wool fibre is made of keratin, a protein with a high nitrogen content and significant internal moisture. When exposed to flame, wool does not melt or drip. Instead it chars, forming a protective carbonaceous layer that slows further burning. Once the flame source is removed, wool tends to self-extinguish. Typical fire-related properties of sheep wool insulation: Property | Typical value | What it means | Ignition temperature | ~560–600 °C | Higher than many organic fibres; lower than mineral wool | Limiting oxygen index (LOI) | ~24–25 % | Needs a flame to keep burning; will self-extinguish when flame is removed | Melting / dripping | None | Chars instead; no molten drips that spread fire | Smoke | Moderate | More smoke than mineral wool, generally lower toxicity than synthetic foams | Fire classification (treated) | Euroclass B or C | Can reach "difficult to ignite" status with boron or other treatments | Treated sheep wool insulation can meet building-code fire requirements for residential and light commercial use. That makes it a viable option for timber-frame walls, lofts, and breathable construction where the primary goal is thermal comfort rather than industrial fire safety. How Mineral Wool Behaves in Fire Mineral wool — rock wool and glass wool — is an inorganic fibre made from molten rock or glass. It is classified as A1 non-combustible under EN 13501-1, which means it does not burn, does not contribute fuel to a fire, and produces negligible smoke or heat release. Key fire properties of mineral wool: Property | Rock wool | Glass wool | Fire classification | A1 non-combustible | A1 non-combustible | Service temperature | Up to ~650–750 °C | Up to ~300–350 °C | Melting point | >1000 °C | ~650–750 °C (softens above service temp) | Combustibility | None | None | Smoke in fire | Very low | Very low | For our full fire-performance guide, see is glass wool fireproof. For temperature limits, see what temperature can rock wool withstand. Side-by-Side Comparison Feature | Sheep wool | Mineral wool (rock wool) | Material origin | Natural organic protein fibre | Inorganic spun rock fibre | Burns in fire | Chars and can smoulder; self-extinguishes when flame removed | Does not burn | Euroclass rating | B/C with treatment | A1 | Maximum service temperature | ~80 °C long-term | ~650–750 °C | Industrial fire safety | Not suitable | Standard choice | Smoke production | Moderate | Very low | Typical use | Homes, timber frames, breathable lofts | Industrial pipe, vessel, furnace, and fire-rated insulation | The difference is not about marketing. It is about chemistry. Sheep wool is an organic material that can be made fire-resistant through treatment. Mineral wool is inorganic and inherently non-combustible. Why Industrial Heat Applications Must Use Mineral Wool In industrial plants, the fire risk is different from a residential setting. Insulation is often installed near hot pipes, furnaces, exhausts, and process equipment where surface temperatures routinely exceed 100 °C and can reach several hundred degrees. In those conditions, sheep wool fails for three reasons. 1. Temperature ceiling Sheep wool insulation is designed for building-service temperatures. Long-term exposure above ~80 °C degrades the fibre and any treatment. Rock wool is stable to ~650–750 °C and ceramic fibre to 1000 °C and above. 2. Fire classification Most industrial fire-safety standards require A1 or A2 non-combustible insulation for high-temperature and fire-rated systems. Treated sheep wool at best reaches Euroclass B or C. That disqualifies it from process piping, fire barriers, and hazardous-area insulation. 3. Combustibility under sustained heat Even flame-resistant organic materials can smoulder or char when exposed to sustained radiant heat or hot surfaces. Mineral wool does not. In a petrochemical or power-plant fire, the last thing the insulation layer should do is add fuel. For marine, petrochemical, power, and furnace applications, mineral wool is not optional — it is a baseline safety requirement. When Sheep Wool Makes Sense Sheep wool insulation has legitimate advantages in the right place: - Timber-frame and breathable construction — regulates moisture and avoids condensation risk. - Lofts and pitched roofs — comfortable to handle, low irritancy, good acoustic absorption. - Renovation projects — easy to cut and fit between studs and rafters. - Sustainability-focused builds — renewable, low embodied carbon. In these applications, sheep wool can meet the required fire performance with appropriate treatment and installation. The mistake is extending that performance claim into industrial high-temperature environments where only A1 mineral wool belongs. Common Myths to Avoid - Myth: "Wool insulation is fireproof." — Sheep wool is flame-resistant, not fireproof. Mineral wool is non-combustible. - Myth: "Natural wool is safer than synthetic mineral wool in a fire." — Mineral wool produces far less smoke and no combustible gases. - Myth: "If it passes a building fire test, it works in a factory." — Building tests and industrial fire curves are different. Industrial specs require A1 classification and verified service temperature. Bottom Line Sheep wool is naturally flame-resistant, will self-extinguish when the flame source is removed, and can be treated to meet residential fire codes. But it is organic and has a low service-temperature ceiling, so it cannot replace mineral wool in industrial heat applications. For industrial pipe, equipment, furnace, and fire-rated insulation, mineral wool — rock wool, glass wool, or ceramic fibre — is the correct choice because it is A1 non-combustible, high-temperature stable, and produces minimal smoke. At Rosewool we supply A1 non-combustible rock wool blanket, board, and pipe sections for industrial fire and thermal insulation. Contact our technical team for material selection based on your service temperature and fire-classification requirements. Related products: Rockwool Insulation Blanket (Rock Wool Blanket) Related applications: Building, Cement FAQ: Q: Is sheep wool fire resistant? A: Yes. Sheep wool is naturally flame-resistant because keratin contains nitrogen and moisture. It chars rather than melts, and tends to self-extinguish when the flame source is removed. However, it is not non-combustible and has a low service-temperature ceiling. Q: Is wool insulation fireproof? A: No insulation made from sheep wool is fireproof. With treatment it can be flame-resistant and meet some building-code requirements, but it remains an organic material that can char and smoulder. Mineral wool is classified as A1 non-combustible, which is the level often described as fireproof in building standards. Q: What is the ignition temperature of wool? A: Sheep wool typically ignites at around 560–600 °C. By comparison, rock wool does not ignite because it is an inorganic fibre with a melting point above 1000 °C. Q: Why can't sheep wool be used for industrial insulation? A: Sheep wool is limited to roughly 80 °C long-term service temperature and at best reaches Euroclass B or C fire rating with treatment. Industrial high-temperature insulation must be A1 non-combustible and stable to several hundred degrees, which only mineral wool or ceramic fibre can provide. Q: Is mineral wool better than sheep wool in a fire? A: For fire safety in high-temperature and industrial applications, yes. Mineral wool is A1 non-combustible, produces very little smoke, does not burn, and can withstand 650–750 °C or more. Sheep wool is better suited to breathable building insulation where fire requirements are less severe. ### A-60 Marine Insulation: How It Works + Thickness Guide URL: https://www.rosetexwool.net/news/a-60-marine-insulation-how-it-works-thickness-guide/ 2026-08-30 | Author: Rosetexwool Editorial | Category: industry insight Summary: Understand SOLAS A-60 marine insulation: fire ratings, temperature limits, typical steel-mineral-wool construction, thickness guidance by ship location, and IMO FTP Code certification. A-60 is the fire rating that ship designers, builders, and classification societies talk about most. It defines a bulkhead, deck, or enclosure that must stop flames and smoke for 60 minutes while keeping the unexposed side within safe temperature limits. The insulation behind that rating is what makes it work. This guide explains what A-60 marine insulation is, how it works, and how thickness is selected for different shipboard locations. It is written for naval architects, marine engineers, shipyards, and procurement teams who need to specify fire-rated insulation that passes class approval. What A-60 Means Under SOLAS A-60 is a fire-resistance class defined by the International Maritime Organization (IMO) Safety of Life at Sea (SOLAS) Convention and tested under the IMO Fire Test Procedures (FTP) Code. The letter "A" means the division is made of steel or equivalent material and is capable of preventing the passage of smoke and flame for the rated time. The number is the minutes of fire resistance: Class | Fire resistance | Insulation value | Typical use | A-60 | 60 minutes | Yes | Engine room boundaries, accommodation corridors, control stations, fuel-tank boundaries | A-30 | 30 minutes | Yes | Decks and bulkheads separating lower-risk spaces | A-15 | 15 minutes | Yes | Secondary partitions, galley boundaries | A-0 | 0 minutes | No | Non-insulated steel divisions that only need integrity | For A-60, A-30, and A-15 divisions, the FTP Code requires that the average temperature rise on the unexposed side does not exceed 140 °C above the initial temperature, and any single point does not exceed 180 °C. That temperature control is the insulation's job. How A-60 Insulation Works An A-60 rated assembly works through three mechanisms that work together during a fire. Integrity — stopping flame and smoke The division must prevent flames and hot gases from passing through for the full 60 minutes. That depends on: - Steel plating — usually 4.5 mm or thicker on steel ships, providing the primary barrier. - Mineral wool or ceramic fibre insulation — fills the cavity and blocks heat transfer. - Fire-resistant cladding — aluminium or galvanized steel sheets that protect the insulation and hold it in place. - Seals and penetration systems — certified fire stops at joints, cable transits, pipe penetrations, and damper openings. Without proper sealing at penetrations, even the best insulation layer will fail the integrity criterion. Insulation — limiting temperature rise The insulation layer slows heat transfer from the fire-exposed steel to the unexposed side. Mineral wool is the most common core material because it combines low thermal conductivity with a high melting point. Typical marine-grade rock wool has: - Thermal conductivity around 0.035–0.040 W/m·K at room temperature - Service temperature up to approximately 650–750 °C - A1 non-combustible classification under EN 13501-1 - Melting point above 1000 °C In a hydrocarbon fire or very high-temperature zone, ceramic fibre or a composite system may be used instead of, or in addition to, rock wool. Structural stability — staying in place The assembly must not collapse or displace during the fire. Stability comes from: - Mechanical fixing — stainless-steel pins, washers, and support rings spaced according to the approved drawing. - Steel framing — stiffeners and frames that resist deformation under thermal load. - Density and compression — higher-density boards or blankets are used where vibration, impact, or airflow could displace the insulation. Typical A-60 Construction A standard A-60 bulkhead or deck on a merchant vessel usually consists of: - Fire-exposed steel plate — 4.5 mm minimum on steel ships. - Insulation layer — rock wool board or blanket, density 80–150 kg/m³, held by pins and clips. - Vapour-barrier or facing — aluminium foil or glass tissue where moisture control is needed. - Outer cladding — 0.5–1.0 mm aluminium or galvanized steel sheet, mechanically fixed. The total thickness of the insulation depends on the fire rating, the location, the density of the wool, and the tested system. Shipyards do not design A-60 thickness from first principles for each project — they use systems that have already been type-approved by a classification society. A-60 Thickness Guide by Ship Location The table below shows typical thickness ranges used in approved marine insulation systems. These are indicative; the actual thickness must come from an approved system drawing for the specific vessel and class society. Location | Typical insulation | Density | Notes | A-60 deck | 50–60 mm rock wool board | 100–140 kg/m³ | Supports foot traffic and deck loads; often clad with steel or aluminium | A-60 bulkhead | 40–60 mm rock wool board/blanket | 80–120 kg/m³ | Single layer or staggered double layer for joints | Engine room boundary | 60–120 mm rock wool or composite | 120–180 kg/m³ | Higher heat load; may use ceramic fibre at hot spots | Fuel tank boundary | 80–150 mm rock wool or composite | 120–180 kg/m³ | Additional safety margin due to fuel risk | Ventilation duct through A-60 division | 30–50 mm rock wool wrap | 80–120 kg/m³ | Insulation extends 450 mm each side of the division; fire damper required | Pipe insulation (A-60 rated) | 40–60 mm rock wool section | 100–150 kg/m³ | With stainless-steel jacket; often used on exhaust and hot-water lines | Decks A-60 decks must carry personnel and sometimes equipment, so the insulation is usually a rigid rock wool board rather than a flexible blanket. Density is higher to resist compression, and the top surface is protected by steel or aluminium cladding. Bulkheads A-60 bulkheads separating accommodation from machinery spaces are often built with a single layer of rock wool board fixed to steel stiffeners. At joints between boards, a 50 mm minimum overlap is standard practice. Staggered double-layer systems improve joint performance and are common in high-risk boundaries. Engine rooms Engine rooms have the highest heat load and vibration. The boundary insulation is often 60–120 mm thick, sometimes in two layers, and may combine rock wool with ceramic fibre at exhaust casings or turbocharger areas. Steel support framing is heavier, and pins are spaced closer together than in accommodation areas. Fuel tanks and hazardous boundaries Where an A-60 division forms the boundary of a fuel tank or other high-risk space, the insulation thickness is usually at the upper end of the range. The density is also higher to improve structural stability under hydrocarbon fire conditions. Ventilation ducts When a ventilation duct passes through an A-60 division, the duct itself must be insulated for a length of at least 450 mm on each side of the division. A certified fire damper must also be fitted. This prevents the duct from becoming a chimney that carries fire and smoke between spaces. Pipe and cable penetrations Cable and pipe penetrations are among the most common failure points in fire tests. Each penetration must use a certified transit or sealing system: - Cable transits — intumescent or ablative seals that expand under heat. - Pipe penetrations — steel sleeves, mineral wool packing, and approved sealant. - Large ducts — fire-rated collars, dampers, or insulated bulkhead penetrations. Certification: IMO FTP Code and Class Societies A-60 insulation cannot simply be bought "off the shelf" and installed. It must be part of a system that has been tested and approved. IMO FTP Code The IMO FTP Code, adopted by resolution MSC.307(88), defines how fire-resistance tests are carried out. The main parts relevant to A-60 insulation are: - Part 1 — Non-combustibility test for insulation materials. - Part 3 — Fire-resistance tests for A, B, and F class divisions, including the 60-minute standard fire test. - Part 5 — Surface flammability and smoke-toxicity tests for interior finishes. A standard A-60 test exposes the sample to the ISO 834 cellulosic time-temperature curve, which reaches approximately 945 °C at 60 minutes. The unexposed side is monitored for temperature rise, and the sample is checked for integrity. Classification society type approval After IMO FTP Code testing, marine insulation systems are submitted to class societies for type approval. Common approvals include: - DNV — DNV-ST-A-053 and related marine rules - Lloyd's Register (LR) — Marine & Offshore type approval - Bureau Veritas (BV) — NR216 and related rules - ABS — Rules for Materials and Welding - CCS — China Classification Society guidelines The type-approval certificate specifies the exact product, thickness, density, fixing method, and cladding. Any deviation from the approved drawing invalidates the rating. A-60 vs H-120: Different Fire Curves A-60 and H-120 are both fire-resistance ratings, but they are not interchangeable because they use different fire curves. Rating | Fire curve | Peak temperature | Typical application | A-60 | ISO 834 cellulosic | ~945 °C at 60 min | Ship accommodation, machinery spaces, cargo ships | H-120 | Hydrocarbon (HC) or UL 1709 | ~1100 °C within minutes | Offshore platforms, FPSOs, LNG carriers, hydrocarbon-risk areas | The hydrocarbon curve heats up much faster than the cellulosic curve. Materials that pass A-60 may not pass H-120 without additional thickness, ceramic-fibre layers, or intumescent coatings. Offshore projects usually specify H-120 or H-60 for hydrocarbon-exposed areas, while merchant ships use A-60. For more detail on marine fire standards, see our guide to marine fire insulation materials and standards. Material Selection: Rock Wool, Ceramic Fibre, or Composite? For most A-60 applications, marine-grade rock wool is the default. It is cost-effective, widely approved, and easy to install. Ceramic fibre is used where: - Continuous surface temperatures exceed 650–750 °C - Hydrocarbon fire ratings such as H-120 are required - The insulation must be thin but high-performing Composite systems use layers of rock wool and ceramic fibre to balance cost and performance. Rosewool supplies marine-grade rock wool blanket and rock wool board for A-60 divisions, as well as ceramic-fibre products for high-temperature and offshore applications. See our marine & offshore application page for an overview of fire-rated insulation solutions for ships and platforms. All materials are supported by ISO 9001 quality management and tested to marine-market standards. Common Specification Mistakes - ** Designing from first principles instead of using an approved system.** A-60 thickness must match a tested and class-approved system, not a general heat-loss calculation. - Ignoring penetrations. Even perfect bulkhead insulation fails if cable or pipe transits are not certified. - Mixing A-60 and H-120 requirements. Offshore hydrocarbon zones need the hydrocarbon curve, not the cellulosic A-60 curve. - Using non-marine-grade products. Products sold for building HVAC often lack the density, facing, and certification needed for shipboard fire divisions. - Omitting the vapour barrier or cladding. The insulation must be protected from mechanical damage, oil, and moisture for the life of the vessel. A-60 is a fire-resistance rating for an assembly, not a reaction-to-fire class for a material. Where a project also needs the European product classification, see our Euroclass reaction-to-fire classification guide. Bottom Line A-60 marine insulation is a system, not a single product. The rating depends on the steel structure, the mineral-wool or ceramic-fibre layer, the cladding, and the sealing of every joint and penetration. Thickness varies by location: around 40–60 mm for accommodation bulkheads and decks, 60–120 mm for engine-room boundaries, and more for high-risk fuel-tank divisions. Always specify from approved system drawings and class-society type-approval certificates. Fire-rated divisions are only part of a vessel's insulation schedule. Engine-room pipework, accommodation thermal and acoustic linings, chilled HVAC ducts, cold rooms and LNG cargo systems are sized from heat-loss and condensation calculations rather than fire-test data — our marine insulation thermal and acoustic specifications guide works through those calculations and the thickness tables that follow from them. At Rosewool we supply A-60-grade rock wool board and blanket for marine and offshore projects, with technical support for density, thickness, and certification matching. Contact our team for project-specific recommendations. Engine-room-specific A-60 boundary build-ups and material choices are covered in our ship engine room & machinery space insulation guide. Related products: Rockwool Insulation Blanket (Rock Wool Blanket) Related applications: Marine & Offshore FAQ: Q: What does A-60 mean in marine insulation? A: A-60 is a SOLAS fire-resistance rating. It means a bulkhead, deck, or enclosure can prevent the passage of flame and smoke for 60 minutes, and the average temperature rise on the unexposed side does not exceed 140 °C with no single point above 180 °C. Q: What material is used for A-60 insulation? A: A-60 insulation is most commonly made from marine-grade rock wool (mineral wool) board or blanket. In high-temperature or hydrocarbon-fire areas, ceramic fibre or composite rock-wool/ceramic-fibre systems may be used. Q: How thick is A-60 marine insulation? A: Typical A-60 thickness ranges from 40–60 mm for accommodation bulkheads and decks, 60–120 mm for engine-room boundaries, and 80–150 mm for high-risk fuel-tank divisions. Exact thickness must come from a class-approved system drawing. Q: What is the difference between A-60 and H-120? A: A-60 is tested against the ISO 834 cellulosic fire curve, reaching about 945 °C at 60 minutes. H-120 is tested against the hydrocarbon fire curve, which heats much faster and reaches about 1100 °C. H-120 is used for offshore platforms and hydrocarbon-risk areas. Q: What certification does A-60 insulation need? A: A-60 insulation systems must be tested under the IMO FTP Code and approved by a recognised classification society such as DNV, Lloyd's Register, Bureau Veritas, ABS, or CCS. The type-approval certificate specifies the exact product, thickness, density, and installation method. Q: Can rock wool be used for A-60 divisions? A: Yes. Marine-grade rock wool board or blanket is the standard core insulation for A-60 divisions on most merchant vessels, provided it is part of a class-approved system with the correct density, thickness, cladding, and sealing details. ### Centrifugal Glass Wool: How It's Made & Why It Matters URL: https://www.rosetexwool.net/news/centrifugal-glass-wool-how-its-made/ 2026-08-29 | Author: Rosetexwool Editorial | Category: industry insight Summary: Centrifugal glass wool manufacturing explained: raw materials, melting, fiber spinning, curing, and why the centrifugal process produces better thermal and acoustic insulation. Centrifugal glass wool is the form of glass wool most commonly used in industrial and building insulation. It is made by melting glass-forming minerals and spinning the molten glass into fine fibres with a high-speed centrifuge. The result is a lightweight, low-density mat with excellent thermal resistance and sound absorption. This article walks through the manufacturing process, explains why the centrifugal method dominates the market, and shows where centrifugal glass wool blanket and board fit in industrial insulation. What Is Centrifugal Glass Wool? Glass wool is a fibrous insulation material made from recycled glass, sand, limestone, and other glass-forming minerals. The fibres trap air, which gives the material its low thermal conductivity. Centrifugal glass wool is produced by a dry mechanical process rather than a wet slurry process, so the fibres are finer, more uniform, and bonded without excess water or energy-intensive drying. The typical end products are rolls, blankets, boards, and pipe sections used for: - HVAC ductwork and equipment - Industrial pipe and vessel insulation - Power plant steam and process lines - Cold storage and chilled-water systems - Acoustic lining and sound attenuation For a comparison of glass wool with rock wool, see our guide on glass wool vs rock wool. Raw Materials and Batch Composition A standard centrifugal glass wool batch contains: - Silica sand (10–40 %) — main glass former - Recycled cullet /碎 glass (15–60 %) — reduces raw material use and melting energy - Limestone / dolomite (7–15 %) — adds durability and chemical resistance - Soda ash (7–15 %) — lowers melting temperature - Borax (2–10 %) — improves fibre quality and moisture resistance - Small amount of thermosetting resin binder — locks fibres together during curing Modern plants increasingly use recycled glass because it lowers melting energy, reduces quarrying, and keeps production cost stable. The binder is typically a phenolic or bio-based thermosetting resin. Formaldehyde-free options are available for applications where indoor air quality matters. The Centrifugal Manufacturing Process The process runs in four main stages. 1. Batch preparation and melting Raw materials are crushed to 5–10 mm, mixed to the target chemistry, and fed into an electric or gas-fired melting furnace. The batch melts at 1300–1500 °C over 1–2 hours. Operators control temperature, redox, and homogeneity because any inconsistency affects fibre diameter and final product strength. 2. Fibre formation by centrifuge Molten glass flows through a rotating spinner with thousands of peripheral holes. Centrifugal force throws glass streams outward, and a high-velocity gas stream attenuates them into fibres typically 5–8 µm in diameter. This is the key difference from older blown-fibre or flame-attenuation processes: Process | Typical fibre diameter | Fibre uniformity | Energy use | Centrifugal spinning | 5–8 µm | High, uniform mat | Lower | Blown / steam attenuation | 8–15 µm | More variable | Higher | Finer, more uniform fibres create smaller air pockets, which reduces thermal conductivity and improves acoustic absorption. 3. Binder application and collection As the fibres form, a spray system applies the thermosetting binder. The fibres are then drawn onto a perforated collection conveyor by negative pressure. The collected web is compressed to the target thickness and density. Density can range from 10 kg/m³ for lightweight rolls up to 96 kg/m³ for heavy-duty boards and pipe sections. 4. Curing, cutting, and finishing The mat passes through a curing oven at 100–250 °C, where the binder cross-links and sets the product thickness. After curing, the product is slit, cut, and optionally faced with aluminium foil, glass tissue, or black glass cloth for moisture resistance, clean handling, or acoustic tuning. The final products are packed in polyethylene or shrink wrap to protect against moisture until installation. Why the Centrifugal Process Matters The centrifugal route has become the industry standard for several reasons. Lower thermal conductivity Finer fibres trap smaller pockets of still air. Typical centrifugal glass wool thermal conductivity at 25 °C is 0.032–0.040 W/m·K. At 50 °C mean temperature it is usually 0.035–0.045 W/m·K, competitive with other fibre insulations in the same density range. Better acoustic absorption The fine fibre structure absorbs mid- and high-frequency sound efficiently. Glass wool blankets and boards commonly achieve noise reduction coefficients (NRC) of 0.85–1.0 depending on thickness and facing. Lower embodied energy Centrifugal production is a dry process. It avoids the water-based slurry, drainage, and drying steps used in some alternative processes, which reduces energy use and emissions per kilogram of product. Consistent thickness and density Controlled collection and compression give uniform density across the roll or board. This matters for thermal calculations and for predictable acoustic performance. Typical Properties and Performance Property | Typical value | Notes | Density | 10–96 kg/m³ | Blankets 10–32; boards 48–96 | Thermal conductivity @ 25 °C | 0.032–0.040 W/m·K | Lower is better | Service temperature | −30 °C to +300 °C long-term; short peaks to 400 °C | Above 350 °C consider rock wool | Fire classification | A1 non-combustible (unfaced) | EN 13501-1 | Acoustic absorption | NRC 0.85–1.0 | Thickness-dependent | Water absorption | <1 % by volume for hydrophobic grades | Faced products lower | These numbers explain why centrifugal glass wool is the default choice for building services, process piping below 300 °C, and acoustic treatment. Where Centrifugal Glass Wool Is Used HVAC and building services Duct lining, air-handling units, and chilled-water pipes use glass wool blanket or board because it combines thermal insulation with sound attenuation. Foil-faced products also act as a vapour barrier. Industrial pipe and equipment For process lines operating up to 250–300 °C, glass wool pipe sections and boards insulate effectively at lower weight than mineral wool. The lower density reduces support load. Power generation Steam lines and auxiliary equipment operating below 300 °C are often insulated with glass wool blanket or board for thermal efficiency and personnel protection. Cold storage and cryogenic support Hydrophobic glass wool grades are used in cold-storage walls and chilled-water systems because they resist moisture uptake better than some competing materials. Acoustic enclosures The high NRC of glass wool makes it a standard fill for acoustic panels, silencers, and machinery enclosures. When to Choose Glass Wool vs Rock Wool Centrifugal glass wool and rock wool overlap in some applications but differ in temperature ceiling and density. A simple rule: - Below 300 °C, with weight or acoustic priority → centrifugal glass wool blanket/board - 300–750 °C, fire barrier, or high humidity/abrasion → rock wool - Above 750 °C → ceramic fiber Rock wool has a higher melting point and better fire-barrier performance, but glass wool is lighter, easier to cut, and has lower thermal conductivity at moderate temperatures. Specification Tips When buying centrifugal glass wool, ask for: - Mean-temperature thermal conductivity across your service range, not just the 25 °C value - Density matched to the mechanical load and support spacing - Facing — plain, aluminium foil, glass tissue, or black acoustic facing - Fire classification — A1 for most industrial applications - Hydrophobic treatment if the product will see condensation or outdoor exposure - Binder type — standard phenolic or formaldehyde-free for indoor air quality Bottom Line Centrifugal glass wool dominates building services and moderate-temperature industrial insulation because the manufacturing process produces fine, uniform fibres at controlled density. That combination gives low thermal conductivity, high acoustic absorption, and easy handling. The process also keeps energy use lower than alternative fibre-forming methods by avoiding wet slurry steps. If your application stays below 300 °C and you need thermal, acoustic, and moisture performance in one lightweight material, centrifugal glass wool is usually the right choice. At Rosewool we supply centrifugal glass wool blanket and board in densities from 10 to 96 kg/m³, with plain, foil, and tissue facings. All products are ISO 9001, CE, and SGS certified. Contact our technical team for density, thickness, and facing recommendations for your project. Related products: Glass Wool Board, Glass Wool Blanket Related applications: Green Building & Retrofit FAQ: Q: What is centrifugal glass wool? A: Centrifugal glass wool is a fibrous insulation material made by melting glass-forming minerals and spinning the molten glass into fine fibres with a high-speed centrifuge. It is supplied as rolls, blankets, boards, and pipe sections for thermal and acoustic insulation. Q: How is centrifugal glass wool made? A: The manufacturing process has four stages: raw-material batching and melting at 1300–1500 °C; centrifugal fibre formation where molten glass is spun into 5–8 µm fibres; binder application and collection on a perforated conveyor; and curing, cutting, and finishing. Q: Why is the centrifugal process better than blown fibre? A: Centrifugal spinning produces finer, more uniform fibres with less energy than blown or flame-attenuation processes. The result is lower thermal conductivity, better acoustic absorption, and more consistent product density. Q: What is the maximum service temperature of glass wool? A: Standard centrifugal glass wool is rated for continuous service up to about 300 °C, with short-term peaks to 400 °C. Above 350–400 °C continuously, rock wool or ceramic fiber is usually the better choice. Q: Is glass wool fireproof? A: Unfaced centrifugal glass wool is classified as A1 non-combustible under EN 13501-1. It does not contribute to fire spread, although organic facings can change the fire classification of the finished product. Q: What is the thermal conductivity of centrifugal glass wool? A: At 25 °C, typical thermal conductivity is 0.032–0.040 W/m·K. At 50 °C mean temperature it is usually 0.035–0.045 W/m·K. Always size insulation using the mean-temperature value for your actual service range. ### Ceramic Fiber Blanket vs Board vs Paper vs Cloth: Which Form When? URL: https://www.rosetexwool.net/news/ceramic-fiber-blanket-vs-board-vs-paper-vs-cloth/ 2026-08-29 | Author: Rosetexwool Editorial | Category: industry insight Summary: Choose the right ceramic fiber form for your application: blanket, board, paper, cloth, rope, tape, or bulk. Compare density, temperature, thermal conductivity, and typical industrial uses. Ceramic fiber is sold in more shapes than most engineers realise. The same alumina-silica material can be needled into a flexible blanket, pressed into a rigid board, vacuum-formed into thin paper, woven into cloth, twisted into rope, or supplied as loose bulk. Each form solves a different problem, and choosing the wrong one usually means poor insulation, faster wear, or a difficult installation. This guide compares the main ceramic fiber forms — blanket, board, paper, cloth, plus rope, tape, and bulk — so you can match form to function. How the Forms Are Made The manufacturing process decides the final structure. All ceramic fiber forms start from melt-spun or blown alumina-silicate fibres, but the post-processing is different. Our rope, tape, cloth and paper buying guide takes the same forms from the procurement side — sizing, reinforcement temperature limits and what to put in an enquiry. Form | Manufacturing route | Fiber structure | Main characteristic | Blanket | Needle-punching layers of fiber | Random 3D mesh | Flexible, compressible, excellent thermal shock resistance | Board | Slurry + vacuum forming + pressing | Layered / compressed | Rigid, self-supporting, flat surface | Paper | Wet-lay vacuum forming | Dense, aligned sheet | Thin, lightweight, easy to die-cut | Cloth | Weaving with reinforcement yarn | Woven grid | Strong, flexible, abrasion-resistant | Rope | Twisted / braided fibres | Twisted strand | Round or square cross-section for seals and packings | Tape | Woven strip, often with reinforcement | Woven band | Edge-stable strip for flange and door seals | Bulk | Loose fibre, no binder | Loose random | Filling, blowing, mixing into other products | The key point is that chemistry can be identical, yet the engineering behaviour is completely different. A 1260 °C blanket and a 1260 °C board contain similar fibres, but one drapes over a pipe and the other supports its own weight on a furnace wall. That split begins at the forming step — needling against vacuum forming — and our ceramic fiber bulk, blanket and board explained guide follows the fibre from the melt line through both routes. Temperature Classes: What the Numbers Mean Ceramic fiber products are grouped by classification temperature — the temperature at which the fibre retains a defined percentage of its original properties after 24 hours. Classification temperature is not the same as continuous service temperature. Grade | Classification temp | Typical continuous service | Fibre chemistry | Standard | 1050 °C (1922 °F) | ≤ 900 °C | Aluminosilicate | High-purity | 1200 °C (2192 °F) | ≤ 1050 °C | Higher alumina | High-alumina | 1350 °C (2462 °F) | ≤ 1200 °C | High alumina | Zirconia | 1430 °C (2606 °F) | ≤ 1300 °C | Alumina-zirconia-silica | Polycrystalline | 1600 °C+ (2912 °F+) | ≤ 1500 °C | Mullite / alumina | In oxidising atmospheres, continuous service temperature is usually 100–150 °C below classification temperature. In reducing or vacuum furnaces the gap can be 200–400 °C. Always specify by continuous service temperature, not the catalogue classification number. Density, Strength and Thermal Conductivity Form has a bigger effect on density and mechanical strength than most buyers expect. The table below shows typical industrial ranges. Form | Bulk density | Typical thickness | Compressive / tensile | Thermal conductivity @ 400 °C | Blanket | 96–160 kg/m³ | 6–50 mm | Low tensile (~0.04 MPa) | 0.09–0.13 W/(m·K) | Board | 220–400 kg/m³ | 10–100 mm | Rigid, compressible | 0.10–0.15 W/(m·K) | Paper | 180–250 kg/m³ | 0.5–10 mm | Low, tearable by hand | 0.08–0.12 W/(m·K) | Cloth | 400–600 kg/m³ | 2–5 mm | High tensile, reinforced | 0.10–0.14 W/(m·K) | Rope | ~300–500 kg/m³ | 6–50 mm dia. | Flexible, compressible | Similar to blanket | Tape | ~400–600 kg/m³ | 2–5 mm thick | High edge strength | Similar to cloth | Bulk | ~60–100 kg/m³ | Loose fill | N/A | Lowest, but settles | Blankets and boards are the workhorses of furnace insulation. Paper and cloth are specialists. Rope and tape solve sealing problems. Bulk is used for filling, repairs, and as raw material for module production. Thermal Shock and Handling Behaviour Thermal shock resistance matters when equipment cycles quickly. A furnace that heats to 1200 °C and cools to ambient every shift will destroy a rigid board faster than a flexible blanket. Form | Thermal shock resistance | Handling notes | Blanket | Excellent — fibres move with expansion | Cuts cleanly, low dust, wraps around curves | Board | Moderate — can crack under rapid cycling | Machines and saws like wood; produces dust | Paper | Moderate | Clean edges, easy to punch; tears if mishandled | Cloth | Good | Drapes well; reinforced edges resist tearing | Rope | Excellent | Compresses into gaps; easy to pack | Tape | Good | Stays flat; good for flange covers | Bulk | Excellent as fill, poor as surface | Requires containment; can settle over time | Which Form for Which Application Furnace linings and hot faces For the hot face of industrial furnaces, kilns, and heaters, the choice is usually between blanket and board. - Blanket is preferred when the lining must conform to a curved shell, absorb thermal expansion, or tolerate thermal cycling. It is installed in layers and held by anchors or modules. - Board is preferred for flat walls, doors, and baffles where a rigid, abrasion-resistant surface is needed. Boards are also common as backup insulation behind castable or brick hot faces. For very high temperatures or severe chemical attack, polycrystalline fibre board or modules are the next step up. The full property set — 1600-1700 °C continuous service, ≤0.5 % shrinkage at 1500 °C, and the 2-8 MPa strength range — is covered in our polycrystalline mullite fiber board guide. Seals, gaskets and expansion joints Where the job is to stop hot gas leakage or fill a moving joint, flexible forms win. - Rope is the default for door seals, ladle lids, and expansion joints in round grooves. - Tape is used for flanges, door edges, and straight-run seals. - Paper is ideal for thin gaskets, sight-glass seals, and precision-cut shims. - Cloth is used for curtains, blankets, and removable insulation pads that see handling. Our ceramic fiber rope sealing guide covers rope and tape selection in more detail. Pipe, duct and vessel wrapping For cylindrical equipment, blankets and cloth are the natural choices. - Blanket is wrapped around pipes and vessels in specified thicknesses, then banded or wired in place. - Cloth is used for removable wraps, pipe penetration seals, and cable protection where abrasion resistance matters. Filling, blowing and repairs Bulk fibre is the right form when the insulation must be poured, blown, or packed into irregular cavities. It is also the raw material used to manufacture folded modules. Because it has no binder, it keeps full temperature rating, but it needs containment and may settle if not packed correctly. Packing density and shot content govern how it performs once installed — see our ceramic fiber bulk grades and application guide for target densities, grade selection, and the blown-versus-spun choice. Selection Decision Tree Use the following questions to narrow the choice. - What is the continuous operating temperature? - Above 1300 °C continuously → zirconia grade or polycrystalline - 1000–1300 °C → high-alumina or zirconia grades - Below 1000 °C → standard or high-purity grades - Does the surface need to support itself? - Yes, flat self-supporting wall → board - No, wraps around a shell → blanket or cloth - Fills a gap → rope, tape, paper, or bulk - Will the equipment cycle rapidly? - Frequent thermal cycling → blanket, cloth, rope, or bulk - Steady-state operation → board or paper - Is abrasion or mechanical handling expected? - High abrasion → board or cloth - Occasional handling → cloth or rope - Static insulation → blanket, paper, or bulk - What is the installation environment? - Clean room, low dust → paper or pre-cut cloth - Field cutting acceptable → blanket or board - Confined space → blanket, rope, or tape Industry-Specific Quick Guide Industry | Common forms | Typical grades | Steel — reheating furnaces, ladles | Board backup, blanket modules, rope seals | 1260–1430 °C | Petrochemical — reformers, crackers | Blanket modules, board hot face, rope seals | 1260–1430 °C | Cement — kilns, preheaters | Blanket, board, bulk fill | 1200–1400 °C | Aluminium — melting and holding | Blanket, board, cloth covers | 1200–1260 °C | Power — boilers, ductwork | Blanket, board, paper gaskets | 1000–1260 °C | Ceramics — kilns and kiln cars | Board, blanket, bulk | 1200–1430 °C | Common Specification Mistakes - Confusing classification temperature with service temperature — a 1430 °C classification fibre may only be rated for 1250–1300 °C continuous service depending on atmosphere. - Using board where blanket is needed — rigid boards crack in highly cyclic furnaces. - Ignoring density tolerance — a "220 kg/m³" board with ±10 % tolerance can vary from 198 to 242 kg/m³. - Choosing paper for load-bearing seals — paper is a gasket material, not a structural seal. - Forgetting reinforcement in cloth — cloth strength comes from the glass or stainless-steel reinforcement yarn; check the reinforcement temperature rating. Bottom Line Ceramic fiber blanket, board, paper, cloth, rope, tape, and bulk are the same material family in different engineered forms. Blanket handles curves and thermal shock. Board provides rigid, self-supporting insulation. Paper solves thin-seal problems. Cloth and rope handle seals, curtains, and removable pads. Bulk fills cavities and feeds module production. The right choice depends on temperature, mechanical load, thermal cycling, and installation constraints. In most plants, several forms are used together — board for the wall, blanket for the lining, rope for the door seal, and paper for the gasket. At Rosewool we supply ceramic fiber blanket, board, paper, cloth, rope, tape, and bulk in standard, high-purity, high-alumina, and zirconia grades, certified to ISO 9001, CE, and SGS. Contact our technical team for form and grade selection based on your furnace or process conditions. Related products: Ceramic Fiber Modules Related applications: Cement FAQ: Q: What is the difference between ceramic fiber blanket and board? A: Ceramic fiber blanket is a flexible, needled material that drapes around curved surfaces and absorbs thermal expansion. Ceramic fiber board is a rigid, pressed product used for flat, self-supporting walls and baffles. Blankets handle thermal shock better; boards resist abrasion and hold their shape without support. Q: When should I use ceramic fiber paper instead of cloth? A: Use ceramic fiber paper for thin, precision gaskets, sight-glass seals, and die-cut shims where low thickness and clean edges matter. Use ceramic fiber cloth for applications that need strength, abrasion resistance, or repeated handling, such as curtains, removable pads, and cable protection. Q: What is ceramic fiber rope used for? A: Ceramic fiber rope is used for round-section seals, expansion joints, door and lid packings, ladle seals, and gland packing. It compresses into grooves and tolerates movement better than rigid boards or papers. Q: What is the maximum temperature for ceramic fiber blanket? A: Standard ceramic fiber blankets are rated for continuous service up to about 900–1050 °C, depending on grade. High-alumina grades reach 1200 °C, zirconia grades about 1250–1300 °C, and polycrystalline fibre blankets can exceed 1400 °C. Continuous service temperature is usually 100–150 °C below the catalogue classification temperature. Q: Can ceramic fiber board be used as a hot face lining? A: Yes, ceramic fiber board can be used as a hot face lining in steady-state furnaces with low abrasion and limited thermal cycling. In furnaces with rapid heating and cooling cycles, a fibre blanket or module lining usually performs better because it resists thermal shock cracking. Q: What is ceramic fiber bulk used for? A: Ceramic fiber bulk is loose fibre used for filling irregular cavities, blown insulation, repair packing, and as the raw material for folded modules. It has no binder, so it retains full temperature rating, but it must be contained and may settle if not packed correctly. Q: How do I choose the right ceramic fiber form? A: Start with continuous service temperature, then decide whether the surface needs self-support. Use board for rigid flat walls, blanket for curved or cyclic surfaces, paper for thin seals, cloth for handled covers, rope and tape for seals and packings, and bulk for filling. Also consider installation access, abrasion, and whether the equipment cycles. Q: Is ceramic fiber the same as glass wool or rock wool? A: No. Ceramic fiber is an alumina-silica refractory fibre designed for temperatures from 1000 °C up to 1600 °C. Glass wool is used up to about 350 °C, and rock wool up to about 650–750 °C. For a detailed comparison, see our guide on high-temperature insulation materials. ### Calcium Silicate Board: Density, Thickness & Thermal Conductivity — Spec Guide URL: https://www.rosetexwool.net/news/calcium-silicate-board-density-thickness-thermal-conductivity-spec-guide/ 2026-08-28 | Author: Rosetexwool Editorial | Category: industry insight Summary: Spec guide for calcium silicate insulation board: density grades 170–270 kg/m³, thickness selection 25–140 mm, thermal conductivity curves, and how to specify size/tolerance for industrial projects. Calcium silicate insulation board is specified by three numbers: density, thickness, and thermal conductivity. Get any one of them wrong and the board either fails mechanically on site, overheats in service, or costs more than the application needs. This guide gives procurement and engineering teams the data they need to specify calcium silicate insulation board correctly. It covers density grades, thickness ranges, how thermal conductivity changes with temperature, and the checklist that turns a generic inquiry into a clear purchase order. Why Density, Thickness & Conductivity Are Linked Density controls mechanical strength. Thickness controls total thermal resistance. Thermal conductivity tells you how much heat passes through each millimetre. These three parameters are not independent choices: - A low-density board insulates better per millimetre but cannot carry load. - A thicker board increases R-value but adds weight and support cost. - Conductivity rises with temperature, so a value that looks good at 100 °C may be unacceptable at 600 °C. The right specification finds the intersection of temperature, mechanical load, energy loss target, and budget. For a broader overview of calsil grades and forms, see our Calcium Silicate Insulation Buyer's Guide (2026). For the wider picture on the material itself — composition, the two temperature grades and where calcium silicate insulation sits against the flexible wools — start with our calcium silicate insulation overview guide. Density Grades: Type I, Type II & Industrial Classes Calcium silicate boards are grouped by maximum service temperature and bulk density. Temperature classes Class | Max continuous temp | Typical crystal phase | Best for | Type I | 650 °C (1200 °F) | Tobermorite | Steam systems, boiler casings, building services | Type II | 1000–1050 °C (1830–1920 °F) | Xonotlite | Furnace backup, cement kiln transitions, petrochemical heaters | Within each temperature class, density determines strength. Industrial practice commonly uses three density grades, even though national standards label them differently. Industrial density grades Grade | Bulk density | Compressive strength (10 %) | Flexural strength | Best for | Light | 170–200 kg/m³ | ≥ 0.40 MPa | ≥ 0.30 MPa | Low-load pipe and duct insulation | Standard | 200–240 kg/m³ | ≥ 0.50 MPa | ≥ 0.35 MPa | General industrial pipe and equipment | High-density (HD) | 240–270 kg/m³ | ≥ 0.60 MPa | ≥ 0.40 MPa | Kiln car decks, ladle covers, load-bearing pads | Type II high-density grades are sometimes called HCS-220 or HCS-270 in supplier catalogues. The numbers refer to nominal density. A high-density calcium silicate board should always be ordered with a density tolerance, for example 220 ± 10 % or 270 ± 10 %, and a certified compressive-strength test report. The grades above stop roughly where most general industrial board ranges stop. Where a spec genuinely depends on carrying load — kiln car decks, ladle covers, aluminium cell components — density runs well past 270 kg/m³, into 800–1200 kg/m³ load-bearing grades and up to 1500 kg/m³ structural grades, and the strength-versus-conductivity trade-off changes shape along the way. Our high-density calcium silicate board properties and uses guide covers that upper range, including why the crystal phase sets the temperature ceiling rather than the density. Thermal Conductivity: The Temperature Curve Matters Calcium silicate conductivity increases almost linearly with temperature. Do not specify from a single room-temperature brochure value. The typical relationship is: λ = λ₀ + 0.00011 × t Where λ is the thermal conductivity in W/m·K, λ₀ is the room-temperature baseline, and t is the mean temperature in °C. Conductivity by grade and temperature Grade | λ₀ @ 25 °C | @ 100 °C | @ 300 °C | @ 600 °C | @ 1000 °C | Light (170 kg/m³) | ≤ 0.048 | ≤ 0.059 | ≤ 0.081 | ≤ 0.114 | — | Standard (220 kg/m³) | ≤ 0.050 | ≤ 0.061 | ≤ 0.083 | ≤ 0.116 | ≤ 0.166 | High-density (270 kg/m³) | ≤ 0.056 | ≤ 0.067 | ≤ 0.089 | ≤ 0.122 | ≤ 0.166 | All values are typical maximums in W/m·K. Always ask the supplier for the mean-temperature curve across your actual service range, not a single point. For high-temperature design, engineers usually size thickness using the conductivity at the mean temperature of the hot and cold faces. Using the 25 °C value on a 900 °C process line will undersize the insulation and lead to excess heat loss. Thickness Range & Thermal Resistance Industrial calcium silicate boards are commonly supplied in thicknesses from 25 mm to 140 mm. Standard board sizes include 600 × 300 mm, 1000 × 500 mm, 1200 × 600 mm, and 1200 × 2400 mm. Custom thicknesses down to 10 mm and special formats are available on request. Thermal resistance R = δ / λ Where δ is thickness in metres and λ is the mean thermal conductivity. The table below shows typical R-values for common thicknesses. Thickness | Light grade R-value | Standard grade R-value | HD grade R-value | 25 mm | 0.42 m²·K/W | 0.40 m²·K/W | 0.36 m²·K/W | 50 mm | 0.85 m²·K/W | 0.81 m²·K/W | 0.73 m²·K/W | 80 mm | 1.36 m²·K/W | 1.29 m²·K/W | 1.16 m²·K/W | 100 mm | 1.70 m²·K/W | 1.61 m²·K/W | 1.45 m²·K/W | 120 mm | 2.04 m²·K/W | 1.94 m²·K/W | 1.75 m²·K/W | 140 mm | 2.38 m²·K/W | 2.26 m²·K/W | 2.03 m²·K/W | R-values are calculated at a mean temperature of approximately 200 °C using typical maximum conductivity values. Your project calculation should use the supplier's certified curve. Layering rule: when total thickness exceeds 80 mm, install in two or more layers with staggered joints. This avoids through-joints and reduces thermal bridging. A common build-up is 80 mm + 40 mm rather than a single 120 mm layer. Thickness Selection by Application The right thickness depends on hot-face temperature, target surface temperature, allowable heat loss, and structural constraints. The examples below are typical industrial starting points. Cement plant Location | Hot-face temp | Suggested grade | Suggested thickness | Cyclone cone / cylinder | 750–950 °C | Type II, 220 kg/m³ | 100–115 mm | Tertiary air duct | 750–950 °C | Type II, 220 kg/m³ | 80–120 mm | Kiln transition zone | 1000–1050 °C | Type II, 270 kg/m³ | 120–140 mm | Steel and metals Location | Hot-face temp | Suggested grade | Suggested thickness | Reheating furnace wall | 1000–1050 °C | Type II, 270 kg/m³ | ≥ 120 mm | Annealing furnace | 800–950 °C | Type II, 220 kg/m³ | 80–100 mm | Hot blast pipe | 500–700 °C | Type I/II, 220 kg/m³ | 60–80 mm | Petrochemical Location | Hot-face temp | Suggested grade | Suggested thickness | Ethylene cracking furnace | 900–1000 °C | Type II, 270 kg/m³ | 80–120 mm | Hydrotreater | 700–800 °C | Type II, 220 kg/m³ | 60–90 mm | FCC unit | 600–750 °C | Type II, 220 kg/m³ | 70–100 mm | Power and boiler Location | Hot-face temp | Suggested grade | Suggested thickness | Boiler casing / duct | 300–500 °C | Type I, 170–220 kg/m³ | 50–70 mm | Steam pipe | 300–600 °C | Type I/II, 220 kg/m³ | 60–100 mm | These are starting points. Final thickness should be calculated using the project's heat-loss target, for example GB/T 4272-2024 or equivalent plant standards that limit surface temperature to ≤ 50 °C and heat loss to ≤ 80 W/m². Board Size, Tolerance & Finish A complete order specification should state: - Board dimensions: length × width × thickness, for example 1200 × 600 × 50 mm - Density grade: 170, 220, or 270 kg/m³, with tolerance, for example 220 ± 10 % - Temperature class: Type I (650 °C) or Type II (1000–1050 °C) - Dimensional tolerance: typically ±2 mm on thickness, ±5 mm on length/width for machined boards - Edge finish: square, bevelled, or tongue-and-groove - Facing: plain, aluminium foil, or glass tissue - Marking: batch number, density grade, production date, and certificate reference on each pack For pipe sections, specify inner diameter, segment length, and whether the inside diameter is based on nominal bore or outside diameter including any existing coating. How to Specify: A 7-Point Checklist - Maximum continuous operating temperature — choose Type I or Type II; account for upset peaks - Peak mechanical load — specify HD grade (≥ 240 kg/m³) for walkable, bolted, or vibration-loaded surfaces - Thermal conductivity curve — require values at 100 °C, 200 °C, 400 °C, 600 °C, and 1000 °C as applicable - Thickness and layering — calculate from heat-loss target, not from a catalogue thickness - Dimensions and tolerances — state length, width, thickness, ID/OD for pipes, and acceptable tolerances - Certification — request A1 non-combustible report, asbestos-free declaration, ISO 9001, CE or SGS marks - Batch traceability — require mill test certificates tied to the production batch Missing one of these is a common reason for rejected deliveries or costly field changes. Common Specification Mistakes - Using room-temperature conductivity for hot-face design — always use the mean-temperature curve - Ordering standard density for a walkable platform — HD grade is needed for point loads and foot traffic - Single-layer thick boards — above 80 mm, layer in two stages with staggered joints - Ignoring tolerance on density — a 220 kg/m³ board with ±10 % tolerance can range from 198 to 242 kg/m³; this affects strength calculations - No batch testing — rely on supplier type tests plus project-specific sampling for critical jobs Bottom Line Specifying calcium silicate board comes down to matching density, thickness, and thermal conductivity to the real operating conditions. Start with temperature to choose Type I or Type II, then use mechanical load to select the density grade, then calculate thickness from the certified conductivity curve and the project's heat-loss target. Always require batch traceability and A1 / asbestos-free certification. At Rosewool we supply calcium silicate insulation board and high-density calcium silicate board in densities from 170 to 270 kg/m³ and thicknesses from 25 mm to 140 mm, certified to ISO 9001, CE, and SGS. Contact our technical team for thickness calculations, density selection, and project-specific specifications. Related products: Calcium Silicate Insulation Board Related applications: Cement, Cryogenic Insulation FAQ: Q: What is the standard density of calcium silicate board? A: The most common industrial density for calcium silicate board is 220 kg/m³, with a typical tolerance of ±10 %. Light grades are 170–200 kg/m³ for better insulation on low-load surfaces. High-density grades are 240–270 kg/m³ for load-bearing or walkable areas. Q: What thickness does calcium silicate board come in? A: Calcium silicate board is typically supplied in thicknesses from 25 mm to 140 mm. Common sizes are 25, 40, 50, 65, 80, 100, 120, and 140 mm. Custom thicknesses down to 10 mm and special formats are available on request. Q: How does thermal conductivity of calcium silicate change with temperature? A: Thermal conductivity increases roughly linearly with temperature. A typical relationship is λ = λ₀ + 0.00011 × t, where λ₀ is about 0.048–0.056 W/m·K at room temperature. At 600 °C, conductivity can be roughly double the room-temperature value, so designs must use the mean-temperature curve. Q: What is the thermal resistance of 50 mm calcium silicate board? A: A 50 mm calcium silicate board has a typical thermal resistance of 0.73–0.85 m²·K/W, depending on density. Lower-density boards have slightly higher R-values because their conductivity is lower. Q: When should I specify high-density calcium silicate board? A: Specify high-density calcium silicate board (≥ 240 kg/m³) when the surface must carry load, support foot traffic, accept bolt-through fixings, or resist vibration. Typical uses include kiln car decks, ladle covers, equipment pads, and furnace components. Q: What is the maximum temperature for Type II calcium silicate board? A: Type II calcium silicate board is rated for continuous service up to 1000 °C, with some high-density formulations reaching 1050 °C. Above 1050 °C continuously, switch to ceramic fiber or polycrystalline mullite insulation. ### Calsil vs Cal-Sil vs Calcium Silicate: Are They the Same Thing? URL: https://www.rosetexwool.net/news/calsil-vs-cal-sil-vs-calcium-silicate-same-thing/ 2026-08-28 | Author: Rosetexwool Editorial | Category: industry insight Summary: Calsil, cal-sil, and calcium silicate are the same rigid, high-temperature insulation material. Learn why the names differ and how to read spec sheets without confusion. If you have ever seen calsil, cal-sil, and calcium silicate on the same spec sheet and wondered whether they are different products, you are not alone. Engineers, procurement teams, and contractors use all three names — sometimes on the same project. The short answer is: they are the same material. The differences are only in spelling and naming convention, not in chemistry or performance. This article explains where each name comes from, what the standards say, and how to make sure you are ordering the right product when the label changes from one document to the next. The Short Answer: Same Material, Three Names Calcium silicate is the standard chemical name. It describes an inorganic, rigid insulation material made mainly from calcium oxide (lime) and silica, cured under high-pressure steam to form crystalline calcium silicate hydrates. Calsil and cal-sil are simply shortened commercial spellings of the same name. They are not separate product categories. If a supplier sells "calsil board," the material still has to meet the same ASTM, EN, or GB standards as "calcium silicate board." Think of it as the difference between "aluminium" and "aluminum" — spelling and regional preference, not a different metal. Once the naming is settled, the next question is what the material actually does: our calcium silicate insulation grades, forms and specification guide walks through it. Why Do the Names Differ? There are three reasons the same material ends up with three labels: - Chemical vs commercial naming - Calcium silicate is the precise chemical name used in standards, contracts, and technical reports. - Calsil is a common commercial abbreviation used in product catalogues, bills of material, and site shorthand. - Cal-sil is another way to write the abbreviation, usually with a hyphen for readability. - Regional habits - North American specs and insulation schedules often use "calsil" or "cal-sil." - European and international documents more often use the full "calcium silicate" name. - Some Asian export catalogues use both spellings interchangeably depending on the target market. - Historical shorthand - "Calsil" has been used in industrial insulation schedules for decades as a quick way to write the material on piping lists and isometric drawings. None of these spellings changes the composition of the board or pipe section you receive. What the Standards Say International standards use the full chemical name, but they cover all common abbreviations because the material is identical. Standard | Name used | Scope | ASTM C533 | Calcium silicate block and pipe insulation | United States industrial specification | EN 14306 | Calcium silicate products | European industrial insulation standard | ISO 8142 | Preformed insulation dimensions | International reference for dimensions | GB/T 10699 | Calcium silicate insulation products | Chinese national standard | When a product is certified to ASTM C533 or EN 14306, it does not matter whether the label says calsil, cal-sil, or calcium silicate. The certificate refers to the material chemistry and physical properties, not the spelling. For a deeper look at how to specify the material, see our Calcium Silicate Insulation Buyer's Guide (2026). Same Properties, Whatever the Name The table below shows typical values for the same calcium silicate insulation, regardless of how it is abbreviated on the drawing. Property | Typical value | Notes | Bulk density | 170–270 kg/m³ | Light to high-density grades | Maximum service temperature | 650 °C (Type I) / 1000–1050 °C (Type II) | Type II uses xonotlite crystal phase | Compressive strength (10 %) | 0.4–0.6 MPa (light) / ≥ 1.0 MPa (HD) | Higher density = higher strength | Thermal conductivity @ 200 °C | 0.055–0.065 W/m·K | Ask for the mean-temperature curve | Fire classification | A1 non-combustible | EN 13501-1 | Water absorption | Low; water-resistant, not waterproof | Protect with cladding outdoors | If a supplier quotes different thermal conductivity or temperature limits just because the name is spelled differently, ask for the test certificate. The name alone should never change the performance numbers. How to Read a Spec Sheet Without Confusion When you see "calsil" or "cal-sil" on a document, treat it as a label check, not a material check. Confirm these four items: - Standard reference — Does it say ASTM C533, EN 14306, GB/T 10699, or equivalent? - Density grade — Is it 170, 220, 270 kg/m³, or another value? This affects strength and conductivity. - Temperature class — Is it Type I (650 °C) or Type II (1000–1050 °C)? - Form — Is it board, pipe section, block, or custom shape? For board specs, see our Calcium Silicate Board Spec Guide. If the document answers these four questions clearly, the spelling of the name does not matter. Watch Out for Other "Sil" Materials The only real risk in naming confusion comes from materials that sound similar but are completely different. Do not mix up calcium silicate with these: - Silica board / silica fiber — Based on silicon dioxide, not calcium silicate. Often much higher temperature, but different chemistry. - Aerogel / silica aerogel — A nanoporous, flexible blanket with extremely low conductivity. It is a different material family, though sometimes used alongside calsil in composite systems. - Silicone foam — An elastomeric foam, usually for low-temperature gasketing. Not a high-temperature insulation. - Silicate cement — A bonding or finishing material, not the insulation itself. If the spec uses only the word "sil" without the full material name, ask for clarification before ordering. Quick Buyer Cheat Sheet You see | It means | What to check | Calcium silicate | Standard chemical name | Density, temperature class, form | Calsil | Abbreviation of calcium silicate | Same as above | Cal-sil | Hyphenated abbreviation | Same as above | Cal sil insulation | Insulation made of calcium silicate | Standard reference and density | Silica / aerogel / silicone | Different material family | Do not substitute without engineering approval | Bottom Line Calsil, cal-sil, and calcium silicate are the same rigid, high-temperature insulation material. The different spellings come from naming habits, regional preferences, and decades of site shorthand. What matters is the standard the product meets, its density grade, its temperature class, and its form — not whether the label has a space or a hyphen. At Rosewool we supply calcium silicate insulation board, calcium silicate pipe, and high-density calcium silicate board certified to ISO 9001, CE, and SGS. Whether your drawing calls it calsil, cal-sil, or calcium silicate, we can match the spec. Contact our team for density selection and project-specific quotations. Related products: Calcium Silicate Insulation Board Related applications: Cement, Iron & Steel FAQ: Q: Is calsil the same as calcium silicate? A: Yes. Calsil is simply an abbreviation of calcium silicate. It is the same rigid, high-temperature insulation material made from lime and silica, cured under high-pressure steam. Q: What does cal-sil mean? A: Cal-sil is a hyphenated commercial abbreviation for calcium silicate. It is used in product catalogues, bills of material, and site drawings. The material is identical to calsil and calcium silicate. Q: Are calsil and cal-sil the same material? A: Yes. Both are shortened names for calcium silicate insulation. The spelling difference has no effect on chemical composition, density, temperature rating, or mechanical properties. Q: Why are there different names for calcium silicate insulation? A: The names come from three sources: the full chemical name used in standards, common commercial abbreviations used in catalogues, and decades of site shorthand on piping and insulation schedules. Regional preferences also play a role. Q: How do I know a product is real calcium silicate? A: Check the standard reference — ASTM C533, EN 14306, or GB/T 10699 — and verify density, temperature class, and compressive strength. A genuine calcium silicate product will list these properties on its certificate, regardless of whether it is called calsil or cal-sil. Q: Is calsil the same as silica or aerogel? A: No. Silica board and silica aerogel are different material families. Calsil is calcium silicate, while aerogel is a nanoporous silica-based blanket. They have different chemistry, density, and handling properties. ### Glass Wool vs Rock Wool: 7 Differences That Decide the Spec URL: https://www.rosetexwool.net/news/glass-wool-vs-rock-wool-7-differences/ 2026-08-27 | Author: Rosetexwool Editorial | Category: industry insight Summary: Glass wool or rock wool? Compare the six forms of each, then temperature, density, fire rating, acoustics, water resistance, conductivity, cost and installation speed. Glass wool and rock wool are both mineral-fiber insulants, both A1 non-combustible, and both widely used in industrial and building applications. But they are not interchangeable. The wrong choice can mean melted insulation, sagging blankets, or money spent on performance you do not need. This guide compares the two materials across the seven differences that actually matter when you write a spec — and, before that, sets out the types of glass wool and the types of rock wool you are really choosing between. Both are family names, not products, and most specification errors start with picking the right material in the wrong form. If you are deciding between a glass wool blanket and a rock wool blanket, start here. Most glass wool vs rock wool comparisons stop at a property table; the form you specify usually decides the outcome first. Quick Decision Table If your project needs... | Choose | Why | Continuous service above 400 °C | Rock wool | Glass wool softens and degrades above ~350–400 °C | Maximum sound absorption (NRC) | Glass wool | Finer fibers absorb mid-to-high frequencies better | Lightest weight on steel roof decks | Glass wool | Density roughly 24–64 kg/m³ vs 80–150 kg/m³ | Fire barrier / fire isolation zone | Rock wool | Higher density and melting point give longer fire resistance | Fast, large-area roll-out | Glass wool | Supplied in long rolls; covers more area per man-hour | Damp or freeze-thaw exposure | Either, with treatment | Both reach ≥ 98 % water repellency when treated | Lowest material cost | Glass wool | Lower raw-material and processing cost | Large-diameter vessel or drum | Rock wool | Supplied as lamella mat that bends without compressing the fibre | Standard stud or joist cavity | Either, as batts | Friction fit at standard centres; form, not fibre, decides | Types of Glass Wool: Six Forms and Where Each Fits "Types of glass wool" is one of the most common queries in this subject area, and the honest answer is that the material barely changes between them. What changes is the form it is delivered in — and that choice is driven by geometry, load and handling, not by chemistry. Every form of glass wool insulation starts from the same base: molten glass spun into fibres of roughly 4–9 µm, bonded with a thermosetting resin, and cured into a stable mat. Our walkthrough of how centrifugal glass wool is made covers the production line step by step. What matters here is what happens after the curing oven. 1. Blanket and roll. The default form, and the one most people mean when they say glass wool. Supplied compressed in long rolls at roughly 10–48 kg/m³, it is unrolled across roof decks, laid over ductwork and draped over irregular plant. It is the fastest form to install per square metre and generally the cheapest per unit of thermal resistance. It carries no load and needs support or cladding. Specification detail sits in our glass wool blanket buying guide. 2. Batt. Pre-cut lengths, friction-fitted between studs, joists or purlins. Same material as blanket, but the dimension is fixed to a standard frame spacing, which removes cutting waste on repetitive work. Where the cavity is regular — partition walls, ceiling grids — batts beat rolls on labour even at identical material cost. 3. Rigid board. The same fibre pressed to a higher density, typically 24–100 kg/m³, with enough rigidity to hold an edge, accept a bonded facing and resist fixing pressure without slumping. This is the form to specify whenever the insulation has to be dimensionally stable or has to carry a finish. The density classes and what each one buys you are set out in our rigid board selection and spec guide, and the application split in where glass wool board earns its place. 4. Pipe section. Pre-formed half-shells or full-round sections sized to a nominal pipe diameter. Density runs higher than roll form, because a curved segment has to hold its geometry against banding pressure and thermal movement without opening at the seam. For hot and cold process pipework this is usually the only sensible form — a blanket wrapped around a pipe compresses on the inside of the curve and loses most of its thickness where it matters most. 5. Loose-fill and blowing wool. Unbonded fibre blown or poured into irregular cavities, lofts and voids where no cut product can be fitted. It has the lowest installed density of the six and no shape of its own, so it is entirely dependent on containment and will settle in an open cavity. 6. Faced and composite variants. Any of the above with a factory-applied facing — foil, Kraft paper, glass tissue, or a reinforced foil scrim. The facing is not decoration. It controls vapour drive, protects the fibre from mechanical damage and air erosion, and on ductwork it doubles as the air-stream surface. Choosing the wrong facing causes more field failures than choosing the wrong density. Two points are worth stating plainly, because they shorten most specification arguments. First, the form does not change the temperature ceiling. A rigid board and a roll from the same line share the same binder and the same upper limit. If the duty is 500 °C, no glass wool form will survive it. Second, the conductivity differences between forms are second-order compared with getting thickness and installed density right. Form is a geometry and handling decision; performance lives in the spec. Types of Rock Wool: The Parallel Family Rock wool is made from basalt and dolomite rather than recycled glass, melted at a higher temperature and spun into coarser, denser fibre. The family runs parallel to glass wool, with two forms that glass wool does not normally offer. Blanket and roll — denser and heavier than the glass wool equivalent, typically 80–150 kg/m³, chosen where temperature and fire rating govern rather than weight. Board — the workhorse form for fire-rated walls, facades and industrial equipment, and the one to specify when the insulation has to survive handling on site. Pipe section — pre-formed for process pipework, and the standard answer above the glass wool temperature ceiling. Loose fill — for cavity and void filling where settlement is acceptable. Wired mat — fibre stitched to a galvanised wire mesh. This is a rock wool form with no common glass wool equivalent: it exists because high-temperature pipework and vessels need a product that can be sewn around a curve and pinned without tearing. Lamella mat — narrow slabs of fibre oriented perpendicular to the facing and bonded to a foil or mesh backing, so the product bends around large-diameter pipe and vessel shells without compressing the fibre on the inside of the curve. That last pair is why rock wool dominates above 400 °C in a way no property table captures. It is not only the melting point — it is that rock wool is supplied in forms designed for hot, curved, mechanically pinned service. Form-by-Form: Which Type Wins Where Read a glass wool vs rock wool comparison form by form rather than property by property, and the answer usually appears faster — most jobs carry a geometry constraint that already rules out half the options. Job | Glass wool form | Rock wool form | Why | Long roof deck runs, light load | Blanket / roll, 16–24 kg/m³ | Blanket, 80–100 kg/m³ | Glass wool covers faster and loads the structure less | Partition or ceiling cavity on standard centres | Batt | Batt | Friction fit either way; form, not fibre, decides | Dimensionally stable, faced, mechanically fixed | Rigid board, 48–100 kg/m³ | Board | Both work; rock wool carries more load | Process pipe below 350 °C | Pipe section | Pipe section | Glass wool is cheaper; rock wool has headroom | Process pipe above 350 °C | — | Pipe section or wired mat | Glass wool binder is out of range | Large-diameter vessel or drum | — | Lamella mat | Bends without compressing the fibre | Fire-rated wall or penetration seal | — | Board | Density and melting point | Irregular void or loft | Loose fill | Loose fill | Containment decides, not the fibre | 1. Service Temperature Temperature is the single most important difference, and it is the one that eliminates a material outright rather than ranking it. - Glass wool: typically rated for –50 °C to 350 °C, with some industrial grades reaching ~450 °C for short periods. Above this the binder begins to degrade and the fibres lose their spring, which is why a glass wool layer that has been overheated looks intact but has lost most of its thickness. - Rock wool: typically rated for –50 °C to 650 °C, with some high-duty grades reaching ~750 °C. The basalt-based fibres have a higher melting point and hold their structure at temperatures where glass wool would slump. The failure mode is worth understanding. It is rarely a dramatic melt — it is binder burn-out followed by gradual compaction. Glass wool insulation that has been overheated stays in place, the cladding still looks fine, and the surface temperature creeps up over months. By the time anyone notices, the layer has lost a third of its design thickness. If your process runs above 350 °C continuously, rock wool is the safer spec. For the exact rock-wool ceiling, see our guide on what temperature rock wool can withstand. 2. Fire Performance Both materials are classified A1 non-combustible under EN 13501-1. Neither will propagate flame or produce significant smoke. The difference shows up under prolonged direct flame or when the material is asked to act as a fire barrier rather than simply not burn. Rock wool's higher density and melting point make it the preferred material for fire-rated walls, fire-stop collars, penetration seals and fire isolation zones. Glass wool provides excellent fire safety for ducts, partitions and ceilings where the temperature stays within its service range, but it is not normally chosen as a primary fire barrier. The practical distinction is integrity time — how long the layer stays in place and continues to insulate the protected side. A non-combustible material that softens and falls out at 500 °C is not a barrier, however good its classification looks on paper. For a deeper look at glass-wool fire behaviour, read is glass wool fireproof. 3. Density & Compressive Strength Density follows directly from the fibre diameter and production process. Material | Typical density | Compressive behaviour | Glass wool blanket | 24–64 kg/m³ | Soft, conformable, low compressive strength | Glass wool board | 24–100 kg/m³ | Rigid, holds an edge, takes fixing pressure | Rock wool blanket | 80–150 kg/m³ | Firmer, higher compressive strength, less sag under load | Rock wool board | 100–200 kg/m³ | Dimensionally stable, used where load or impact matters | The higher density of rock wool makes it better for applications where the insulation must support its own weight over long spans, such as large steel-framed roofs or vertical wall cavities. Glass wool's lower density reduces structural load and makes it easier to cut and fit around services. On long roof runs that is usually decisive: glass wool roof insulation in blanket form adds a fraction of the dead load of a rock wool layer at the same thermal resistance, which is why it is the default on lightweight steel decks. A useful rule: specify the lowest density that survives installation. Insulation is compressed by banding, by cladding fixings and by foot traffic during maintenance, and every kilogram per cubic metre above what the job needs is spent on a property nobody asked for. 4. Thermal Conductivity At room and moderate temperatures, glass wool usually has a slight edge. Both materials follow the same pattern — conductivity rises with mean temperature as radiation across the pore structure becomes a larger share of total heat transfer. Mean temperature | Glass wool | Rock wool | 25 °C | 0.032–0.040 W/(m·K) | 0.035–0.045 W/(m·K) | 100 °C | 0.040–0.050 W/(m·K) | 0.044–0.055 W/(m·K) | 200 °C | 0.055–0.070 W/(m·K) | 0.058–0.072 W/(m·K) | The gap narrows as temperature rises. More importantly, rock wool keeps its conductivity stable at temperatures where glass wool would be degrading. Specifying insulation by a single low-temperature conductivity value is a common mistake: always check the mean-temperature curve across the actual service range, and check it at the hot-face condition rather than at ambient. 5. Acoustic Performance Glass wool's fibres are finer and more uniform, giving it excellent sound absorption across mid and high frequencies. It is the usual choice for acoustic ceilings, duct liners, plant rooms and building partitions where speech and machine noise dominate. Rock wool absorbs sound well, especially at lower frequencies, and its higher mass improves airborne sound insulation. It is often used in cinemas, studios and industrial enclosures where low-frequency energy is the problem. On the numbers that actually decide an acoustic bid — noise reduction coefficient and weighted absorption coefficient — the two sit close together at equal thickness, and rock wool's advantage comes mostly from mass rather than from the absorption mechanism itself. Our glass wool acoustic insulation guide sets out the NRC and αw data, the partition and ceiling constructions that reach them, and the cases where glass wool is the wrong answer. For rigid board applications, compare glass wool board and rock wool board against the project's acoustic target rather than its thermal target — the density that optimises one is rarely the density that optimises the other. 6. Water Resistance & Moisture Behavior Both materials can be supplied with water-repellent treatment, typically reaching ≥ 98 % water repellency. Untreated, the behaviour differs: - Glass wool drains water relatively well after short-term wetting and dries faster because of its open, fine-fibre structure. However, prolonged soaking collapses the blanket and destroys thermal performance. - Rock wool absorbs less water by mass but can hold moisture in its denser fiber matrix. Once saturated, it takes longer to dry. In practice, both materials should be protected with a vapor barrier or cladding in wet locations. The choice between them should be driven by temperature and mechanical loads, not by small differences in water absorption. The real risk is not the water itself but what it does to the thermal calculation. A wet insulation layer conducts several times better than a dry one, and the loss is invisible until the surface temperature or the energy bill moves. Our guide on whether glass wool blanket is waterproof covers where the treated grades genuinely hold and where they do not. 7. Cost & Installation Speed Glass wool is generally the lower-cost option, both in material and labour for large areas. Long rolls can be unrolled quickly across roof decks and ductwork. Rock wool is more expensive per square metre and is often supplied in boards or shorter rolls that require more cutting. The trade-off is durability and temperature headroom. Factor | Glass wool | Rock wool | Material cost | Lower | Higher | Roll length / coverage | Longer rolls, faster coverage | Shorter rolls or boards, more cuts | Cutting | Easy with knife | Denser; requires saw or insulation knife | Labour speed on large areas | Faster | Slower | Lifetime in harsh service | Good | Better at high temperature and load | How to Choose: A 5-Step Framework Use this sequence when writing the spec — the order matters, because each step eliminates options rather than ranking them. - Check the temperature. If continuous service is above 350 °C, eliminate glass wool unless the hot face is protected by a higher-temperature material. - Check the load and span. If the insulation must carry its own weight over a wide cavity or roof span, favour rock wool's higher density — or move from blanket to rigid board. - Pick the form, not just the fibre. Blanket, batt, board, pipe section, loose fill or faced composite. On a pipe, a wrapped blanket loses thickness on the inside of the curve; a pre-formed section does not. - Check acoustic and budget priorities. For maximum sound absorption at the lowest cost, glass wool wins. For fire barriers and high-temperature duty, rock wool wins. - Check the facing and the weather. Facing, vapour control and cladding decide service life more often than the fibre does. Common Mistakes - Specifying glass wool on a 500 °C steam pipe — the binder burns out and the blanket compacts. - Using rock wool for light acoustic ceiling tiles — heavier, harder to handle, and more expensive than necessary. - Wrapping blanket around small-bore pipe instead of using a pre-formed section — the insulation compresses exactly where the geometry works against it. - Ignoring facing and cladding — both materials need protection from weather and liquid water, regardless of water-repellent treatment. - Comparing only material price — installation labour, longevity and reline frequency often outweigh the per-metre cost difference. - Assuming the form changes the rating — a board and a roll from the same line share the same temperature ceiling. Once the material choice is made, the buying decisions take over. For supplier audit, density selection and the enquiry checklist that settle a purchase, see our glass wool supplier selection guide. Bottom Line Glass wool and rock wool solve different problems. Glass wool is the lighter, more acoustically absorbent, lower-cost choice for temperatures up to about 350 °C. Rock wool is the higher-temperature, higher-density, fire-barrier choice for service up to 650–750 °C. Within each family, the form does most of the work. Getting the types of glass wool straight — blanket, batt, board, pipe section, loose fill and faced composite — usually settles the specification faster than any property comparison, and the same logic runs through the rock wool family on the other side of the temperature line. Glass wool insulation is the right answer up to roughly 350 °C; above that the question stops being about properties at all. A glass wool vs rock wool decision that never gets past the property table tends to produce the right material in an unbuildable form. At Rosewool we manufacture both glass wool blankets and boards and rock wool blankets, boards, and pipes since 1982, with ISO 9001, CE, and SGS certification. Contact our team for a spec matched to your temperature, acoustic, and fire requirements. Related products: Calcium Silicate Insulation Board, Glass Wool Board Related applications: Building, Cement FAQ: Q: What are the main types of glass wool? A: Six forms cover practically every job: blanket and roll for large-area coverage, batts for standard stud and joist cavities, rigid board where dimensional stability or a bonded facing is needed, pipe sections for process pipework, loose fill for irregular voids, and faced or composite variants where vapour control or an air-stream surface matters. The fibre is the same in all six — the form decides how it is installed and what it can carry. Q: Which type of glass wool is best for pipe insulation? A: A pre-formed pipe section. Wrapping blanket around a pipe compresses the fibre on the inside of the curve, so the layer loses thickness exactly where the thermal path is shortest. Pipe sections are supplied denser than roll form and sized to nominal pipe diameter, which also makes banding and cladding straightforward. Q: What is the difference between glass wool blanket and glass wool board? A: Blanket is a flexible roll at roughly 10–48 kg/m³ that drapes over irregular shapes and covers large areas quickly. Board is the same fibre pressed to 24–100 kg/m³ so it holds an edge, accepts a facing and resists fixing pressure. Choose blanket for coverage speed and board whenever the insulation has to stay flat, carry a finish or keep its thickness under load. Q: Is glass wool or rock wool better for sound absorption? A: Glass wool absorbs more at mid and high frequencies because its fibres are finer and more uniform, which is why it dominates acoustic ceilings and duct liners. Rock wool's advantage comes from mass: at equal thickness the absorption coefficients are close, but the heavier product insulates better against airborne low-frequency energy. For speech and machine noise, glass wool. For studios and heavy plant enclosures, rock wool. Q: Can glass wool be used at 400 °C? A: Only briefly. Standard glass wool is rated for continuous service to about 350 °C, and while some industrial grades tolerate short excursions to roughly 450 °C, sustained operation at 400 °C burns out the binder and the layer compacts. Above 350 °C continuous, rock wool is the correct specification. Q: Are both glass wool and rock wool non-combustible? A: Yes. Both are classified A1 non-combustible under EN 13501-1 and neither propagates flame or generates significant smoke. The distinction is integrity under fire rather than combustibility: rock wool's higher melting point and density keep it in place far longer, which is why it is the material specified for fire barriers, penetration seals and fire isolation zones. Q: Which is cheaper, glass wool or rock wool? A: Glass wool, on both material and installed cost for large areas. It is lighter to handle, supplied in longer rolls and cuts with a knife. Rock wool costs more per square metre and needs more cutting time, but it lasts longer in high-temperature and high-load service, so the lifecycle comparison narrows considerably on hot plant. Q: Does the form change the temperature rating of glass wool? A: No. A rigid board and a roll from the same production line share the same binder and the same upper limit, roughly 350 °C continuous for glass wool. Changing the form changes handling, dimensional stability and load capacity — not the temperature ceiling. Q: Can I use glass wool instead of rock wool? A: Only if the service temperature stays within the glass wool limit and the application does not require high compressive strength or fire-barrier performance. For continuous temperatures above 350 °C, rock wool is the safer choice. Q: Which is more water resistant, glass wool or rock wool? A: Both can be treated to reach ≥ 98 % water repellency. Untreated glass wool drains and dries faster but is easily damaged by prolonged soaking. Untreated rock wool absorbs less water by mass but dries more slowly. Both should be protected with cladding or a vapor barrier in wet locations. ### Calcium Silicate Insulation: The Complete Buyer's Guide (2026) URL: https://www.rosetexwool.net/news/calcium-silicate-insulation-buyers-guide-2026/ 2026-08-27 | Author: Rosetexwool Editorial | Category: industry insight Summary: 2026 buyer's guide to calcium silicate insulation: temperature ratings, density, thermal conductivity, forms, and how to specify calsil for industrial projects. Calcium silicate insulation — also called calsil or cal-sil — is a rigid, asbestos-free, inorganic material used to insulate pipes, vessels, and equipment from roughly 650 °C up to 1050 °C. It is the material engineers turn to when a lining must stay flat, carry load, and survive high humidity or occasional water contact without slumping. This guide is written for procurement and engineering teams who need to specify calcium silicate in 2026. It covers what the material is, how the grades differ, which form to order, and the checklist that separates a successful specification from a site problem. What Is Calcium Silicate Insulation? Calcium silicate insulation is manufactured by reacting lime (calcium oxide) and silica under high-pressure steam in an autoclave. The reaction forms crystalline calcium silicate hydrates — mainly the tobermorite phase in standard boards and the xonotlite phase in many high-temperature grades. These crystal structures give calsil its low thermal conductivity, dimensional stability, and rigidity. The manufacturing sequence matters for buyers because it explains why calsil behaves differently from fibrous insulants. A slurry of lime, silica, and reinforcing fiber is cast or pressed into shape, then cured under saturated steam at temperatures typically between 170 °C and 210 °C. The result is a pre-crystallized, load-bearing solid rather than a bonded mat of fibers. Because the structure is crystalline, it does not soften or lose strength at its rated service temperature. Unlike flexible mineral-wool blankets, calcium silicate is a rigid board or pipe section. It does not rely on a binder to hold its shape, so it keeps its dimensions after repeated heating and cooling cycles. Modern formulations are reinforced with non-asbestos fibers for handling strength and are classified as A1 non-combustible under EN 13501-1. For a shorter introduction to the material, see our article on what is calsil (calcium silicate) insulation. Temperature Ratings: Standard Grade vs High-Temperature Grade The first specification decision is temperature class. Calcium silicate products fall into two broad groups: Grade | Max continuous service temp | Typical crystal phase | Common uses | Standard | 650 °C (1200 °F) | Tobermorite | Steam pipes, boiler casings, HVAC ducts, fire-rated walls | High-temp | 1000–1050 °C (1830–1920 °F) | Xonotlite | Furnace backup linings, cement kiln transitions, petrochemical heaters | A common mistake is to size calsil for a 650 °C average when the skin temperature spikes above 1000 °C during upset conditions. If the continuous operating temperature is above 650 °C, specify the high-temperature grade. If the temperature is above 1050 °C continuously, switch to ceramic fiber blanket or polycrystalline mullite fiberboard. High-temperature grades achieve their extra headroom through higher xonotlite content and tighter process control during autoclaving. They cost more than standard grades, but they eliminate the risk of shrinkage, cracking, and loss of compressive strength in hot zones. For buyers, the safest rule is: size for the peak continuous temperature, not the average. Density, Thermal Conductivity & Mechanical Strength Density is the next filter after temperature. Higher density means higher compressive strength and slightly higher thermal conductivity at low temperatures, but better durability and load-bearing capacity. The table below shows typical industrial grades. Density grade | Bulk density | Compressive strength (10 %) | Thermal conductivity @ 200 °C | Best for | Light | 170–200 kg/m³ | 0.4–0.6 MPa | ≤ 0.055 W/m·K | Low-load pipe and duct insulation | Standard | 200–240 kg/m³ | 0.6–1.0 MPa | ≤ 0.060 W/m·K | General industrial pipe and equipment | High-density (HD) | 240–300 kg/m³ | ≥ 1.0 MPa | ≤ 0.065 W/m·K | Load-bearing pads, kiln car decks, heavy equipment | At higher temperatures, thermal conductivity rises. A board rated at 0.050 W/m·K at 100 °C may read 0.110–0.130 W/m·K at 600 °C. Always ask suppliers for the mean-temperature curve across the full service range, not a single room-temperature value. Designing from a single low-temperature conductivity number is one of the most common causes of under-specified insulation thickness on hot process lines. Mechanical strength is just as important as thermal performance in many applications. Standard calcium silicate can support light foot traffic and cladding loads. High-density boards can support structural loads such as kiln car decks, ladle covers, and equipment pads. If your application involves bolt-through fixings, point loads, or vibration, specify compressive strength explicitly and confirm the test method. Forms: Board, Pipe, Block & Custom Shapes Calcium silicate is supplied in four main forms. Choosing the right one reduces field cutting, improves joint quality, and shortens installation time. Board Flat rectangular boards are the most common form. Standard dimensions are often 1200 × 2400 mm or 1000 × 2000 mm, with thicknesses from 10 mm to 100 mm. Boards are used for: - Furnace and kiln backup linings - Fire-rated wall and ceiling cores - Boiler and duct casings - Equipment pads where a flat, structural surface is needed For high-load areas, specify high-density calcium silicate board. Pipe sections Pre-curved segments match common pipe diameters and are supplied in halves or segments for easy fitting. They are widely used in: - Power plant steam and hot-water lines - Petrochemical process piping - Refinery heaters and transfer lines See the full calcium silicate pipe range for diameter and thickness options. Block & custom shapes Thicker blocks and engineered shapes are used for kiln car decks, ladle covers, and furnace components where standard boards would require too many joints. Custom shapes are normally CNC-machined or cast to drawing. Calsil vs Rock Wool vs Ceramic Fiber Calcium silicate is often compared with rock wool and ceramic fiber. The choice depends on temperature, form, and whether the surface must carry load. Property | Calcium silicate | Rock wool | Ceramic fiber | Max continuous temp | 650–1050 °C | ~750 °C | up to 1430 °C | Form | Rigid board / pipe | Flexible blanket / board / pipe | Flexible blanket / module / board | Compressive strength | High (load-bearing) | Low | Very low | Water resistance | Low uptake, dimensionally stable | Repels water if treated; can sag if saturated | Poor — absorbs water and loses insulation value | Handling dust | Minimal | Fibrous | Fibrous (PPE required) | Relative cost | Mid | Low | Higher | Decision rule: use calcium silicate insulation board where rigidity, dimensional stability, or load-bearing matters; use rock wool blanket for curved or irregular surfaces on a budget; use ceramic fiber blanket when temperatures exceed 1000 °C continuously. For a deeper look at the rock-wool temperature ceiling, read our guide on what temperature rock wool can withstand. Where Calcium Silicate Insulation Is Used Calsil appears wherever a rigid, high-temperature insulant is required. Typical 2026 applications include: - Power generation — boiler casings, steam piping, flues, and ductwork. The rigid pipe sections stay in place on long horizontal runs without sagging. - Petrochemical — heater and reformer backup linings, pipe supports, and hot process piping. The material resists hydrocarbon exposure and supports cladding. - Cement & lime — kiln transition zones, preheater towers, and cooler roofs. High-temperature grades handle the cyclic thermal shock of kiln rotation. - Metals — reheating furnace backup, ladle covers, and tundish linings. High-density boards carry the mechanical loads of molten-metal handling equipment. - Marine & offshore — A-60 fire-rated bulkheads and deckheads. Calsil's A1 rating and low smoke emission make it ideal for SOLAS fire divisions. - Building services — fire-rated walls, smoke-extract ducts, and penetration seals. Boards provide a flat, stable substrate for cladding systems. In composite linings, calsil usually sits on the cold side as a structural backup, while ceramic fiber or rock wool handles the hot face. This combination gives the hot-face temperature resistance of fiber and the structural integrity of a rigid board. Global Standards & Certifications Industrial calcium silicate is covered by several standards. Specifying the correct standard avoids mismatched test methods and false claims. Standard | Region | Scope | ASTM C533 | United States | Calcium silicate block and pipe thermal insulation | EN 14306 | Europe | Calcium silicate products for industrial installations | GB/T 10699 | China | Calcium silicate insulation products | ISO 8142 | International | Reference for preformed insulation dimensions | For export projects, CE marking and SGS test reports are usually required. For fire-critical applications, request an A1 non-combustible classification report to EN ISO 1182 and EN ISO 1716. An asbestos-free declaration should be on the supplier's letterhead, not just a generic material safety data sheet. Procurement Checklist: What to Specify A complete calcium silicate specification should include the following items. Missing any of them is a common cause of rejected deliveries or field delays. 1. Temperature class State the maximum continuous operating temperature and any upset or cyclic peak. Use 650 °C standard grade or 1000–1050 °C high-temp grade accordingly. If the peak exceeds 1050 °C for more than a few hours per year, consider ceramic fiber or mullite instead. 2. Density and mechanical strength Define the required density range and compressive strength at 10 % deformation. For walkable or load-bearing surfaces, specify high-density board ≥ 240 kg/m³ with compressive strength ≥ 1.0 MPa. For simple pipe insulation, 200–240 kg/m³ is usually sufficient. 3. Dimensions and tolerances List board size, thickness, pipe nominal diameter, segment length, and acceptable dimensional tolerance. For pipe sections, confirm whether the inner diameter is nominal bore or outer diameter. Tolerances of ±2 mm on thickness and ±5 mm on length are common for machined boards. 4. Thermal conductivity curve Require thermal conductivity values at 100 °C, 200 °C, 400 °C, and 600 °C minimum. A single-point value is not enough for design calculations. Request the curve at mean temperatures that cover your actual service range. 5. Fire and environmental certification Ask for: - A1 non-combustible test report (EN ISO 1182 / EN ISO 1716) - Asbestos-free declaration - ISO 9001 quality management certification - CE or SGS marks for export projects 6. Batch testing and traceability For large projects, require mill test certificates tied to the production batch. Consider third-party sampling for density, conductivity, and compressive strength before acceptance. Marking each pack with batch number, production date, and density grade is the minimum traceability requirement. 7. Facing and finish Specify whether boards need a facing (aluminum foil, glass tissue, or none) and whether edges should be square, beveled, or tongue-and-groove. Foil facing can reduce dust during installation and act as a vapor barrier; un-faced boards bond better with high-temperature cements. Common Specification Mistakes to Avoid Even experienced buyers can mis-specify calcium silicate. The most frequent errors include: - Mixing up standard and high-temp grades — a standard 650 °C board placed in a 900 °C zone will shrink and crack within months. - Designing from a single conductivity value — insulation thickness must be calculated from the mean-temperature curve, not the room-temperature brochure figure. - Ignoring compressive strength — walking on or bolting through a low-density board causes crushing and hot spots. - Wrong pipe ID — pipe sections sized by nominal bore may not fit over the actual outer diameter including existing insulation or coating. - No batch testing — relying solely on the supplier's initial type-test report instead of per-batch certificates invites out-of-spec material. Installation & Handling Notes Calcium silicate is easy to handle but brittle. Follow these practices on site: - Storage — keep boards and pipe sections dry and off the ground. Calsil is water-resistant, not waterproof; prolonged soaking can weaken surface layers. - Cutting — use a fine-tooth saw or carbide-tipped cutter. Wear a dust mask even though the material is low-dust. - Fixing — boards can be mechanically fixed with studs and washers or adhered with compatible high-temperature adhesives. Pipe sections are usually wired or banded in place. - Joints — stagger board joints between layers. Fill gaps with compatible calcium silicate cement or insulating filler. - Protection — finish with aluminum, galvanized steel, or stainless-steel cladding in outdoor or wash-down areas. For multi-layer systems, the outer layer should overlap the joints of the inner layer by at least 100 mm. On vertical pipes and vessels, install sections from the bottom up so that each upper section overlaps the one below, preventing water ingress. Cost, Service Life & ROI Calcium silicate costs more per square metre than rock wool but less than ceramic fiber or aerogel. Its value comes from longevity and low maintenance. In high-temperature industrial service, a correctly specified calsil lining can last 15–30 years with minimal degradation. Energy savings from reduced heat loss usually repay the material cost within 2–4 years on hot process lines. The bigger payback often comes from avoided downtime: a rigid, dimensionally stable lining does not slump or hot-set like some flexible materials, so reline cycles are longer and emergency repairs are fewer. When evaluating quotes, compare total installed cost rather than material price alone. Calsil's rigidity can reduce support steel, cladding complexity, and labor hours on pipe runs. On equipment pads and kiln cars, the higher compressive strength of high-density boards reduces creep and extends service life. Bottom Line Calcium silicate insulation is the right choice when your application needs a rigid, load-bearing, high-temperature insulant that stays dimensionally stable in humid or cyclic conditions. Start with the temperature class, then select density and form. Specify the full thermal conductivity curve, confirm A1 non-combustible and asbestos-free certification, and tie acceptance testing to the production batch. At Rosewool we have manufactured calcium silicate boards, pipes, and custom shapes since 1982, supplying power, petrochemical, cement, and marine projects with ISO 9001, CE, and SGS certified materials. Contact our engineering team for density selection, thickness calculations, and project-specific specifications. Manufacturer & Supplier of Calcium Silicate Insulation A calcium silicate insulation supplier is only as good as the dimensional stability and batch consistency of the boards and pipe sections it ships. When you shortlist a calcium silicate board manufacturer, confirm the mill can hold flatness, edge squareness and the declared density across the full 1000–1100 °C temperature class — not just on a sample panel. What to verify before you order - Independent test reports covering thermal conductivity, compressive strength and A1 non-combustible classification - ISO 9001, CE and SGS certification scoped to the actual product line being quoted - Density and thickness tolerances tied to the production batch, with traceability to raw material - Capacity to supply board, pipe sections and custom shapes from one source Product forms we supply - Calcium Silicate Pipe — pre-formed sections for steam and process lines - Calcium Silicate Insulation Board — rigid load-bearing panels for furnaces and vessels - Calcium Silicate Insulation hub for grades, sizes and project data A bulk calcium silicate pipe covering insulation distributor should show mill-direct origin and batch certificates; Rosewool manufactures these shapes in-house and has done so since 1982, serving power, petrochemical, cement and marine projects worldwide. Contact our engineering team for density selection and thickness calculations. Related products: Calcium Silicate Insulation Board Related applications: Cement FAQ: Q: What is calcium silicate insulation used for? A: Calcium silicate insulation is used for high-temperature pipe, vessel, and equipment insulation where rigidity and dimensional stability matter. Common applications include steam piping, boiler casings, furnace backup linings, cement kilns, petrochemical heaters, and A-60 marine fire barriers. Q: What is the maximum temperature for calcium silicate insulation? A: Standard calcium silicate insulation is rated for continuous service up to 650 °C. High-temperature grades reach 1000–1050 °C. Above 1050 °C, ceramic fiber or polycrystalline mullite boards are the better choice. Q: Is calcium silicate insulation waterproof? A: Calcium silicate is water-resistant, not waterproof. It has low capillary absorption and stays dimensionally stable if it gets wet, but prolonged immersion should be avoided. Outdoor or wash-down applications should be protected with metal cladding. Q: How does calsil compare to rock wool? A: Calsil is rigid and load-bearing, rated to 650–1050 °C, and holds its shape under compression. Rock wool is flexible, lower cost, and rated to about 750 °C. Use calsil for structural, rigid surfaces; use rock wool for curved or irregular surfaces on a budget. Q: What density calcium silicate board should I specify? A: For general pipe and equipment insulation, 200–240 kg/m³ is standard. For load-bearing surfaces such as kiln car decks or walkable platforms, specify high-density board at 240–300 kg/m³ with compressive strength ≥ 1.0 MPa. Q: Is calcium silicate insulation asbestos-free? A: Yes. Modern calcium silicate insulation is made from lime, silica, and non-asbestos reinforcing fibers. It contains no asbestos and is safe to handle with normal site PPE. ### Top 10 High-Temperature Insulation Materials (2026) URL: https://www.rosetexwool.net/news/top-10-high-temperature-insulation-materials-2026/ 2026-08-26 | Author: Rosetexwool Editorial | Category: industry insight Summary: 2026 buyer's guide to the 10 best high-temperature insulation materials — mullite, ceramic fiber, aerogel, calcium silicate — with temperature limits and uses. Choosing high-temperature insulation comes down to three numbers: the maximum continuous service temperature, the thermal conductivity, and the form factor that fits your equipment. This 2026 roundup ranks the ten materials our engineering team specifies most often for furnaces, kilns, boilers, and process equipment above 1000 °C — with honest temperature ceilings and where each one earns its place. How We Ranked the Top 10 The list is ordered by maximum continuous service temperature, because that is the first filter any high-temperature spec must pass. (If you are lining a furnace specifically, our heat-resistant materials for furnace guide organises the same materials by duty rather than by temperature ceiling.) A material rated for 1700 °C continuous outranks one rated for 1000 °C, regardless of cost. We then note conductivity and typical use so you can trade temperature headroom against thickness and budget. # | Material | Max continuous temp | Typical use | 1 | Polycrystalline mullite fiberboard | 1600–1700 °C | Hot-face furnace & lab linings | 2 | Refractory ceramic fiber blanket | 1260–1430 °C | Furnace, kiln, boiler linings | 3 | Refractory ceramic fiber board | 1260–1430 °C | Rigid hot-face & backup boards | 4 | Ceramic fiber modules | 1260–1430 °C | Quick furnace wall lining | 5 | Ceramic fiber paper | 1260 °C | Gaskets, seals, wrapping | 6 | Ceramic fiber rope | 1050–1260 °C | Door & expansion-joint seals | 7 | Ceramic fiber bulk | 1050–1430 °C | Loose-fill & feedstock | 8 | Nano insulation board (microporous) | 1000–1200 °C | Thin-wall high-temp insulation | 9 | Nano aerogel insulation blanket | up to 1000 °C | Space-limited retrofit | 10 | Calcium silicate insulation board | 1000–1050 °C | Pipe & equipment insulation | 1. Polycrystalline Mullite Fiberboard — 1600–1700 °C Polycrystalline mullite fiberboard is the only fibrous board on this list rated for continuous service above 1600 °C. Its fully crystalline mullite structure gives it low shrinkage and high purity that standard glass-phase ceramic fiber cannot match. - Best for: hot-face linings in steel reheating furnaces, heat-treatment furnaces, ceramic and glass kilns, laboratory and tube furnaces, and semiconductor crystal-growth hot zones. - Key limit: the "1900 °C" figure is a short-term survival peak, not a continuous rating. Size it for 1600–1700 °C service. - See the full polycrystalline mullite board guide for grade selection. 2. Refractory Ceramic Fiber Blanket — 1260–1430 °C Refractory ceramic fiber blanket (RCF blanket) is the workhorse of high-temperature insulation. Standard grades serve to 1260 °C; high-purity and zirconia-containing grades reach 1430 °C. - Best for: furnace and kiln linings, boiler and duct insulation, expansion-joint packing, and backup behind dense refractory. - Form factor: rolls and blankets, easy to cut and anchor; also available as ceramic fiber plus blanket for higher density. - Safety note: RCF is classified as a substance of concern above 1000 °C; use proper PPE and prefer encapsulated or low-bio-persistence alternatives where regulations require. 3. Refractory Ceramic Fiber Board — 1260–1430 °C Refractory ceramic fiber board is the rigid cousin of the blanket. It holds a flat shape, machines cleanly when cold, and serves as a self-supporting hot-face or backup board. - Best for: burner blocks, sight-hole covers, kiln car decks, and baffles where a rigid shape is needed. - Pair with: ceramic fiber board alternatives for non-RCF options. 4. Ceramic Fiber Modules — 1260–1430 °C Ceramic fiber modules are pre-compressed blanket blocks with integral anchors, engineered for fast furnace-wall lining. They cut installation time versus laying blanket row by row. - Best for: new furnace linings and rapid relines of existing furnaces and heaters. 5. Ceramic Fiber Paper — 1260 °C Ceramic fiber paper is a thin, flexible sheet made from refined ceramic fibers. It is the go-to gasket and seal material in high-temperature joints. - Best for: gaskets, flame curtains, wrapping heating elements, and separation layers. - Related forms: ceramic fiber cloth for woven fabrics and ceramic fiber tape for narrow sealing strips. 6. Ceramic Fiber Rope — 1050–1260 °C Ceramic fiber rope is braided or twisted fiber used for sealing and gasketing. It conforms to irregular gaps that rigid boards cannot. - Best for: furnace and kiln door seals, expansion-joint packing, and boiler manhole gaskets. - Shaped parts: ceramic fiber special-shaped parts for custom seals. 7. Ceramic Fiber Bulk — 1050–1430 °C Ceramic fiber bulk is the loose, un-bonded raw fiber. It is used as loose-fill insulation, as feedstock for vacuum-formed shapes, and for packing hard-to-reach cavities. - Best for: void filling, crucible wrapping, and as the base material for boards, papers, and modules. - Grade map: 1050 / 1100 / 1260 / 1430 °C grades by alumina content. 8. Nano Insulation Board (Microporous) — 1000–1200 °C Nano insulation board uses a microporous structure to approach the theoretical conductivity limit of still air. At the same temperature it is a fraction of the thickness of fibrous insulation. - Best for: where wall thickness is fixed and you need maximum insulation in minimum space — furnace doors, ladle covers, and heat-treatment equipment. - Background: see our insulation glossary for how microporous ("Pyrogel-class") materials work. For the full specification picture — the 0.016–0.030 W/(m·K) conductivity range, the ISO 18959:2025 temperature classes, and where ultra-thin board actually pays back — see our nano microporous insulation thickness and conductivity guide. To see how this family stacks up against aerogel and vacuum panels on conductivity, temperature and cost, read our ultra-thin insulation comparison across all three families. 9. Nano Aerogel Insulation Blanket — up to 1000 °C Nano aerogel insulation blanket combines silica aerogel with a fiber carrier for the lowest thermal conductivity of any flexible blanket we supply. It is the retrofit king where space is tight. - Best for: space-limited retrofits on pipes, vessels, and furnaces; compare it directly in our aerogel vs traditional insulation guide. - Tradeoff: higher cost per mm than ceramic fiber; use it where thickness is the constraint. 10. Calcium Silicate Insulation Board — 1000–1050 °C Calcium silicate insulation board is a rigid, water-resistant board with excellent dimensional stability and low creep under load. It is the standard for high-temperature pipe and equipment insulation. - Best for: steam pipes, heaters, and process equipment where rigidity and load-bearing matter. - Variants: high-density calcium silicate board for higher strength, and calcium silicate pipe for pre-formed pipe sections. Also see composite silicate plate. How to Choose the Right Material By service temperature - Above 1600 °C — polycrystalline mullite fiberboard only. - 1260–1430 °C — RCF blanket, RCF board, ceramic fiber modules. - 1000–1200 °C — microporous board, aerogel blanket, calcium silicate board. - Below 1000 °C — rock wool and glass wool remain the cost-effective choice (see the full catalog below). By application - Furnace / kiln hot face — RCF blanket or board; mullite for the hottest zones. - Pipe & equipment — calcium silicate board/pipe; aerogel where space is tight. - Seals & gaskets — ceramic fiber rope, paper, cloth, tape. - Rapid reline — ceramic fiber modules. Complete Product Catalog For the full range, browse every high-temperature insulation product we manufacture: Ceramic fiber family - Refractory Ceramic Fiber Blanket - Ceramic Fiber Plus Blanket - Refractory Ceramic Fiber Board - Ceramic Fiber Board Alternative - Ceramic Fiber Modules - Ceramic Fiber Bulk - Ceramic Fiber Rope - Ceramic Fiber Paper - Ceramic Fiber Cloth - Ceramic Fiber Tape - Ceramic Fiber Special-Shaped Parts Ultra-high-temperature & nano - Polycrystalline Mullite Fiberboard - Nano Insulation Board - Nano Aerogel Insulation Blanket Calcium silicate - Calcium Silicate Insulation Board - High-Density Calcium Silicate Board - Calcium Silicate Pipe - Composite Silicate Plate Rock wool (up to ~750 °C, for lower-temperature duty) - Rockwool Insulation Blanket - Rock Wool Board - Rockwool Pipe Insulation - Rock Wool Strips - Rock Wool Acoustic Panels - Rock Wool Blanket with Glass Fiber Mesh - Rock Wool Wired Insulation Blanket Glass wool (up to ~450 °C) - Glass Wool Blanket - Glass Wool Board For how these same materials are selected across a whole process site — distillation, cracking, storage and traced lines — see our petrochemical insulation guide by process unit. Bottom Line There is no single "best" high-temperature insulation — only the right one for your service temperature, space, and load. For continuous duty above 1600 °C, polycrystalline mullite fiberboard is the answer. From 1260–1430 °C, refractory ceramic fiber in blanket, board, or module form covers most furnaces and kilns. Below that, microporous board, aerogel, and calcium silicate win on thickness and rigidity. At Rosewool we have manufactured high-temperature insulation since 1982, with ISO 9001, CE, and SGS certification across the full product range. Contact our engineering team for material selection and thickness recommendations matched to your exact service temperature and cycle profile. Related products: Calcium Silicate Insulation Board, Ceramic Fiber Bulk, Ceramic Fiber Paper Related applications: Building, Green Building & Retrofit, Marine & Offshore FAQ: Q: What is the highest-temperature insulation material? A: For continuous service, polycrystalline mullite fiberboard leads at 1600–1700 °C. Short-term exposure up to ~1900 °C is possible in mullite and oxide-fiber systems, but sustained operation above 1700 °C requires ultra-high-purity alumina or zirconia-based boards. Q: What is the difference between ceramic fiber blanket and board? A: They share the same aluminosilicate fiber and the same 1260–1430 °C rating. The blanket is a flexible roll; the board is the same fiber needled and bonded into a rigid, machinable shape that can stand on its own as a hot-face or backup board. Q: Is aerogel better than ceramic fiber for high-temperature use? A: Not automatically. Aerogel has the lowest conductivity of any flexible blanket but is capped near 1000 °C. Ceramic fiber serves to 1430 °C (blanket/board) and mullite to 1700 °C. Choose aerogel when thickness is the constraint and the temperature stays under 1000 °C; choose ceramic fiber when the temperature is higher. Q: What insulation is used above 1000 °C? A: Refractory ceramic fiber in blanket, board, or module form covers 1260–1430 °C. Polycrystalline mullite fiberboard covers 1600–1700 °C. Between 1000–1200 °C, microporous board, aerogel blanket, and calcium silicate board are common choices. Q: Is ceramic fiber safe to handle? A: Refractory ceramic fiber (RCF) is classified as a substance of concern above 1000 °C. Use PPE (gloves, respirator, eye protection) when cutting or installing, and prefer encapsulated or low-bio-persistence grades where local regulations require them. ### Ceramic Fiber Rope: Sealing & Gasketing Applications URL: https://www.rosetexwool.net/news/ceramic-fiber-rope-sealing-gasketing-applications/ 2026-08-26 | Author: Rosetexwool Editorial | Category: industry insight Summary: Ceramic fiber rope is a flexible, asbestos-free solution for high-temperature seals, expansion joints and gaskets. Compare types, reinforcements, installation rules and industry applications. Ceramic fiber rope has become the default flexible sealing material for industrial equipment operating above the practical limit of rubbers and compressed-fiber sheets. It handles continuous temperatures that would destroy most organic seals, remains chemically stable in many process environments, and contains no asbestos — a combination that has made it the replacement of choice for legacy asbestos rope in furnaces, boilers, kilns and engine compartments. This article explains what ceramic fiber rope is, how the different constructions and reinforcements affect performance, how it should be installed, and where it delivers the strongest results across cement, power generation, marine, chemical and metals-processing plants. 1. What Is Ceramic Fiber Rope? Ceramic fiber rope is a flexible cord or braid made from aluminosilicate ceramic fibers, usually combined with a reinforcement yarn. Ceramic fiber rope is supplied as round braid, square braid, twisted rope, twisted tape or hollow sleeve, and it is used to seal doors, expansion joints, flanges, valve stuffing boxes and other gaps that see high temperature, thermal cycling or limited mechanical movement. For side-by-side form selection, sizing rules and reinforcement temperature limits across rope, tape, cloth and paper, see our ceramic fiber forms buying guide. The base fiber is the same family found in ceramic fiber bulk and ceramic fiber blanket products, so the rope inherits the same non-combustible, low-conductivity chemistry. The difference is the textile construction, which gives the material conformability and allows it to be stuffed, wrapped or braided into joints. 2. Key Material Properties Temperature Range The working limit depends on fiber grade and reinforcement: Grade | Continuous Temperature | Short-Term Peak | Standard aluminosilicate | 1,000 °C | 1,260 °C | Zirconia-containing (high purity) | 1,350 °C | 1,430 °C | This range covers most industrial furnace, boiler and exhaust applications. Above 1,260 °C continuous, advanced products such as polycrystalline mullite or alumina fiber become necessary. Thermal Conductivity At 1,000 °C, typical ceramic fiber rope conducts in the range of 0.15–0.18 W/(m·K) — lower than traditional refractory brick and significantly lower than metal gaskets. The low conductivity keeps outer surfaces cooler, reduces heat loss and improves personnel safety. Chemical Stability Ceramic fiber rope tolerates most industrial atmospheres: - pH 4–14 media, excluding strong alkalis such as sodium or potassium hydroxide and strong acids such as hydrofluoric or phosphoric acid. - Oil, water vapor and many hydrocarbons. - Intermittent contact with molten aluminum and zinc in well-designed seals. For severely corrosive environments, zirconia-containing grades or stainless-steel-reinforced constructions are normally specified. Mechanical Properties The textile construction determines the balance between sealability and elasticity: - Round and square braided ropes are dense (typically 550–700 kg/m³), with higher compressive strength and lower recovery. They suit static seals up to about 0.6 MPa. - Twisted ropes and tapes are lighter (380–500 kg/m³) and more elastic, making them ideal for expansion joints and doors that move during heating and cooling. - Hollow sleeve rope is the lightest construction (around 300 kg/m³) and is often used for cable and pipe wrapping where both fire protection and thermal insulation are needed. Typical tensile strength is ≥0.8 MPa. Ropes above 50 mm diameter are usually reinforced with metal wire or high-temperature glass yarn to prevent stretching or structural collapse in service. Health and Environmental Notes Ceramic fiber rope is asbestos-free. During the first heat-up, any organic binder or processing aid carbonizes and may produce a short period of light smoke. This is normal and does not indicate failure. Once the organic fraction has burned out, the rope consists only of inorganic ceramic fibers and remains stable and non-irritating under normal handling conditions. 3. Product Types and Constructions Type | Cross-Section | Density (kg/m³) | Typical Use | Round braided rope | Circular | 550–700 | Static seals, door seals, stuffing boxes | Square braided rope | Square / rectangular | 550–700 | Flange and groove packing | Twisted rope / tape | Circular or flat | 380–500 | Expansion joints, frequent thermal movement | Hollow sleeve rope | Tubular | ~300 | Cable/pipe fire wrap, high-temperature sleeves | Reinforcement Options Reinforcement | Continuous Temperature | Peak Temperature | Characteristics | Glass fiber yarn | 650–1,000 °C | 1,260 °C | Good electrical insulation, moderate strength | Stainless-steel wire | 1,000–1,260 °C | 1,430 °C | High strength, abrasion resistance, higher pressure | Glass-reinforced ropes are preferred for electrical insulation and moderate-temperature seals. Stainless-steel reinforcement is the choice for high-pressure flanges, large-diameter seals, severe vibration or mechanical handling loads. 4. Installation Guidelines A ceramic fiber rope seal is only as good as its installation. The following practices are standard across most industrial applications: - Surface preparation. Remove oil, rust scale, dust and old packing. A clean, dry surface is essential for contact and adhesion. - Sizing. Select a rope diameter roughly 10–15 % larger than the groove or joint gap so the rope is under light compression when the joint is closed. Common diameters range from 5 mm to 100 mm; coils are normally supplied in 30–100 m lengths. - Compression allowance. After installation, the rope should be compressed by about 10–15 % of its original diameter. Over-compression crushes the fiber structure and reduces recovery; under-compression leaves a leak path. - High-temperature sealant. For joints requiring very low leakage, coat the rope or joint faces with a compatible high-temperature sealant before closing. This fills surface imperfections and improves gas-tightness. - Joint staggering. In multi-turn packing, stagger the cut ends so they do not line up and create a straight leak path. - First heat-up. Heat slowly to allow organic processing aids to carbonize without pressure buildup. A controlled initial bake is especially important for large furnace doors. Pressure Rating Guidance - Low pressure (≤0.6 MPa): dense round or square braided rope. - Medium to high pressure: stainless-steel-reinforced braided rope. - Extreme pressure or high-integrity flanges: consider combining rope with a metal gasket or specially engineered high-density ceramic rope designed for the application. Special-Service Recommendations - Thermal cycling: use twisted or three-dimensionally braided constructions with better recovery. - Vibration: choose dense round or square braid and increase the number of packing rings. - Corrosive atmospheres: specify zirconia-containing fiber with stainless-steel reinforcement. 5. Industry Applications Cement Industry Cement kilns, preheaters and coolers are classic ceramic fiber rope applications in cement plants. The rope seals rotary-kiln feed and discharge ends, tertiary-air ducts and cooler partition walls. Reported field benefits include lower shell temperatures, reduced heat consumption and longer seal life than legacy asbestos rope. Zirconia grades are often chosen where alkali vapor is present. Power Generation In coal, biomass and waste-to-energy boilers, ceramic fiber rope seals inspection doors, soot-blower openings and high-temperature flange joints. It replaces asbestos rope and some metal-jacketed gaskets where conformability is needed. Because it is non-combustible, it also contributes to fire-safety compliance in turbine enclosures and ductwork. For broader thermal insulation in power plants, see power generation applications. Marine and Offshore Shipboard exhaust systems, engine compartments and incinerators use ceramic fiber rope for high-temperature sealing and fire containment. Marine specifications often require resistance to salt-laden air and vibration, so stainless-steel-reinforced grades are common. The material satisfies the non-combustible requirements of IMO SOLAS and similar naval standards when qualified to the correct grade. Marine thermal-management context is covered in our marine and offshore applications page. Chemical and Petrochemical Reformers, crackers, furnaces and high-temperature reactor flanges use ceramic fiber rope where temperatures exceed the limits of graphite or PTFE packings. The rope tolerates many process vapors and allows thermal movement in cycling units. In petrochemical plants it is often paired with ceramic fiber blanket and board systems for complete high-temperature envelopes. See petrochemical applications for related insulation system guidance. Metals Processing Aluminum holding furnaces, die-casting machines and molten-metal transfer systems use ceramic fiber rope to seal lids, launder covers and door frames. The material withstands intermittent splashing by molten aluminum and zinc and accommodates the thermal growth of steel shells. High-purity zirconia grades are preferred where metal contact is frequent. 6. Comparison with Traditional Sealing Materials Property | Ceramic Fiber Rope | Asbestos Rope | Rubber Gasket | Metal Gasket | Continuous temperature | 650–1,430 °C | 600–800 °C | 200–400 °C | 500–1,200 °C | Thermal conductivity at 1,000 °C | 0.15–0.18 W/(m·K) | 0.20–0.25 | — | 0.4–0.5 | Tensile strength | ≥0.8 MPa | 0.3–0.6 MPa | 2.0–3.0 MPa | 200–300 MPa | Chemical resistance | Good | Moderate | Limited | Good | Asbestos-free | Yes | No | Yes | Yes | Service life | Long | Moderate | Short | Long | Installation flexibility | High | Moderate | High | Moderate | Ceramic fiber rope does not match the tensile strength of a metal gasket or the room-temperature sealability of rubber, but it occupies a unique position: it is flexible, installable on-site, thermally stable and asbestos-free across the temperature range where most organic and compressed-fiber seals fail. 7. Limitations and Future Trends Current Limitations - First heat-up smoke. Organic processing aids must burn out; users should expect a brief smoke period during initial commissioning. - Strong acid / alkali attack. Not suitable for hydrofluoric acid, phosphoric acid or concentrated caustic service without specialist grades. - Initial cost. Higher purchase price than commodity asbestos-replacement sheets, although longer service life usually offsets the difference. Technology Trends - 3D braided structures. New braiding patterns improve density uniformity and reduce surface dusting, with better retention of tensile strength after thermal cycling. - Rare-earth stabilization. Zirconia and yttria additions push usable temperatures higher and improve fiber crystallization resistance. - Specialized formulations. Anti-seawater, low-binder and radiation-resistant grades are expanding the addressable market. - Digital design. AI-assisted textile engineering is shortening the development cycle for application-specific rope constructions. 8. Conclusion Ceramic fiber rope is a practical, asbestos-free sealing solution for joints that see high temperature, thermal cycling and limited mechanical movement. The right rope is chosen by matching the fiber grade, reinforcement and braid construction to the temperature, pressure and chemical environment. When installed with proper compression and, where needed, a compatible high-temperature sealant, it delivers long service life and lower heat loss than legacy materials. Rosewool supplies ceramic fiber rope, ceramic fiber bulk, blanket and related high-temperature insulation products, manufactured under ISO 9001, CE and SGS certifications from a supply base established in 1982. For help selecting the right rope diameter, fiber grade and reinforcement for your furnace, boiler or engine application, contact our technical team. For related reading, see our overview of ceramic fiber bulk grades and uses and our insulation glossary covering A1, ceramic fiber and microporous materials. Related products: Ceramic Fiber Rope Related applications: Aerospace & Defense, Cement, Environmental & Dust Removal FAQ: Q: What is ceramic fiber rope used for? A: Ceramic fiber rope is used as a flexible high-temperature seal for furnace doors, expansion joints, flanges, valve stuffing boxes, kiln seals and exhaust systems. It replaces asbestos rope in applications up to 1,260 °C, or up to 1,430 °C for short-term peaks with zirconia grades. Q: What temperature can ceramic fiber rope withstand? A: Standard aluminosilicate ceramic fiber rope is rated for continuous use up to 1,000 °C and short-term exposure to 1,260 °C. Zirconia-containing grades can operate continuously at up to 1,350 °C and reach 1,430 °C for short periods. Q: Should I choose glass fiber or stainless-steel reinforcement? A: Choose glass-fiber reinforcement for moderate temperatures (up to ~1,000 °C) and where electrical insulation matters. Choose stainless-steel wire reinforcement for higher temperatures, higher pressure, mechanical abrasion, large diameters or severe vibration. Q: How do you install ceramic fiber rope for sealing? A: Clean the joint surface, select a rope diameter 10–15 % larger than the gap, compress it by 10–15 % when closing the joint, and stagger cut ends in multi-turn packing. For gas-tight joints, apply a compatible high-temperature sealant and perform a slow first heat-up to burn out organic binders. Q: Is ceramic fiber rope a safe replacement for asbestos? A: Yes. Ceramic fiber rope contains no asbestos. It is non-combustible and chemically stable in most industrial environments. During first heat-up, organic processing aids may carbonize and produce brief smoke; this is normal and ceases once the rope is fully conditioned. ### Polycrystalline Mullite Board: Ultra-High-Temp (1900°C) URL: https://www.rosetexwool.net/news/polycrystalline-mullite-board-ultra-high-temp-1900c/ 2026-08-26 | Author: Rosetexwool Editorial | Category: industry insight Summary: Polycrystalline mullite fiber board handles continuous service up to 1600–1700 °C and short-term peaks to 1900 °C. Compare density, conductivity, and applications. Polycrystalline mullite fiber board (PMFB) is a rigid, ultra-high-temperature insulating board made from interlocked polycrystalline mullite fibers. It fills the gap between standard ceramic fiber boards, which top out near 1260–1430 °C, and dense refractory brick, which is heavy and thermally massive. When the choice is about form rather than grade — board against panel, tile or sheet across the whole material range — the insulation board and panel forms guide sets the vocabulary out family by family. The result is a lightweight board that can withstand continuous service up to 1600–1700 °C and short-term peaks approaching 1900 °C. For standard dimensions and grade options, see our polycrystalline mullite fiber board product page. What Makes Polycrystalline Mullite Different Standard ceramic fiber board is produced from spun aluminosilicate glass fibers that are then needled and bonded. At temperatures above 1100–1200 °C, the glassy phase begins to devitrify and shrink, limiting long-term use. Polycrystalline mullite fiber is made by sol–gel processing and controlled crystallization. The fibers consist almost entirely of 3Al₂O₃·2SiO₂ (mullite) crystals, with no residual glass phase. This crystalline structure gives PMFB three decisive advantages: - Higher temperature ceiling — continuous 1600–1700 °C, short-term 1800–1900 °C - Lower shrinkage — ≤0.5 % linear shrinkage after 24 h at 1500 °C in many grades - Higher purity — typical Al₂O₃ content 72–75 %, with high-purity grades reaching 80 %+ Property | PMFB | Standard Ceramic Fiber Board | Dense Refractory Brick | Bulk density | 0.6–1.2 g/cm³ | 0.25–0.35 g/cm³ | 2.0–2.6 g/cm³ | Thermal conductivity (mean 800 °C) | 0.15–0.35 W/(m·K) | 0.12–0.18 W/(m·K) | 0.8–1.5 W/(m·K) | Max continuous use | 1600–1700 °C | 1000–1400 °C | 1650–1800 °C | Short-term peak | ~1900 °C | ~1300 °C | ~1800 °C | Compressive strength | 2–8 MPa | 0.1–0.5 MPa | 20–80 MPa | The tradeoff is clear: PMFB is heavier and stiffer than blanket, but far lighter and easier to cut than refractory brick, with thermal conductivity roughly one-third to one-half that of brick. Key Performance Characteristics Thermal Stability and Shrinkage The defining performance metric for ultra-high-temp boards is shrinkage at temperature, not just the maximum rating. Many refractory materials look good on paper but lose 3–5 % of their volume after the first heat-up, creating gaps and hot spots. Polycrystalline mullite boards typically show: - Linear shrinkage ≤0.5 % after 24 h at 1500 °C - Linear shrinkage 1–3 % after 24 h at 1600 °C, depending on grade - Decomposition begins around 1830–1850 °C as mullite dissociates into alumina and liquid silica This means the "1900 °C" figure is a short-term survival limit, not a continuous operating temperature. For reliable 24/7 service, designers should stay within the 1600–1700 °C envelope and allow extra thickness for the predicted shrinkage zone. Thermal Shock and Mechanical Strength PMFB handles thermal cycling better than dense brick because its fibrous microstructure can absorb differential expansion. Reported performance includes: - Thermal shock resistance: survives repeated cycling between room temperature and 1500 °C without through-cracking in properly graded boards - Compressive strength: 2–8 MPa — adequate for self-supporting boards, baffles, and burner surrounds - Thermal expansion coefficient: approximately 5 × 10⁻⁶ /K, matching most refractory linings The board can be machined with standard woodworking tools when cold, but cutting after first firing is more difficult due to surface sintering. Chemical Resistance High alumina content makes PMFB resistant to most furnace atmospheres, including: - Oxidizing atmospheres up to the temperature ceiling - Neutral and mildly reducing conditions - Most molten aluminum and non-ferrous slags - Weak acids and alkalis It is not recommended in environments with strong alkalis, hydrofluoric acid, or prolonged contact with iron oxide-rich slags above 1500 °C. Where Polycrystalline Mullite Board Is Used High-Temperature Industrial Furnaces PMFB is widely used as hot-face insulation, back-up insulation, and baffles in furnaces where standard fiber boards would shrink or degrade. Common positions include: - Soaking pits and reheating furnaces in steel plants - Ladle and tundish covers - Heat-treatment furnace hot faces - Ceramic kiln car tops and burner walls - Glass furnace regenerator walls and crown backup Because the board is rigid, it can support its own weight as a vertical or horizontal baffle, eliminating the need for metal supports inside the hot zone. Laboratory and Specialty Furnaces Laboratory box furnaces, tube furnaces, and atmosphere-controlled furnaces frequently specify polycrystalline mullite boards for the chamber lining because: - They reach 1700–1800 °C without contamination from binders that burn out at lower temperatures - The surface does not powder or flake into the chamber - They provide a stable, flat mounting surface for heating elements and crucibles Nuclear and Aerospace Applications In nuclear-power and high-temperature test environments, PMFB serves as: - Thermal insulation around high-temperature test fixtures - Backup lining for hot isostatic presses (HIP) - Heat shields and standoffs in plasma and arc-heater facilities Its low neutron activation potential and thermal stability under transient heat loads make it preferable to organic or glass-fiber insulations in these roles. Semiconductor and Crystal Growth Crystal-growth furnaces, CVD reactors, and diffusion furnaces need a chemically stable hot-zone insulation that does not outgas or particle-shed at 1400–1700 °C. Polycrystalline mullite board meets this requirement and is easier to replace than monolithic castables. How PMFB Compares Above 1500 °C At 1500 °C and above the field narrows to four realistic options, and the choice is about shrinkage and chemistry more than headline temperature. Material | Continuous limit | Shrinkage at 1500 °C | Relative cost | Choose it when | Polycrystalline mullite fiber board | 1600–1700 °C | 1–3 % | Medium-high | General ultra-high-temp rigid lining | Alumina fiber board | 1600–1800 °C | <1 % | High | Higher purity or tighter shrinkage control | Zirconia ceramic fiber | 1350–1600 °C | Low | Very high | Alkali-bearing atmospheres | Dense refractory brick | 1650–1800 °C | Low | Low–medium | Load-bearing, slag resistance | Standard ceramic fiber board | 1000–1400 °C | 3–5 %+ (fails) | Low | Not applicable at this temperature | The practical read: PMFB is the value point. Alumina fiber buys you tighter shrinkage and a higher ceiling at a significant price premium. Zirconia fiber is a chemistry choice, not a temperature choice — you specify it for alkali resistance even though its ceiling is lower. Brick is cheaper per kilogram but carries 3–5× the thermal mass and roughly 4× the conductivity, so it costs more in energy over the campaign. Standard ceramic fiber is simply out of its depth here. For the Y-PSZ zirconia insulation tier above 1800 °C and its selection against AZS, see our guide to alumina zirconia ultra-high-temperature fiber. How to Select the Right Grade By Temperature Service temperature | Recommended grade | Notes | 1400–1500 °C | Standard polycrystalline mullite | Cost-effective replacement for high-grade ceramic fiber board | 1500–1650 °C | High-purity mullite (72–75 % Al₂O₃) | Best balance of shrinkage resistance and strength | 1650–1800 °C | Ultra-high-purity mullite (≥80 % Al₂O₃) | Short-term cycling, laboratory furnaces | >1800 °C | Consider zirconia or alumina fiber systems | PMFB is not rated for continuous service here | By Density - 0.6–0.8 g/cm³ — lightest, lowest thermal mass, lower mechanical strength - 0.8–1.0 g/cm³ — general-purpose industrial grade - 1.0–1.2 g/cm³ — highest strength and erosion resistance, used where gas velocity is high By Thickness Typical boards are supplied in 25 mm, 50 mm, and 100 mm thicknesses. Multi-layer systems usually pair a thin, dense hot-face board with a thicker, lower-density backup board to balance hot-face durability and overall insulation value. Specifying PMFB: What to Put on the Purchase Order "1900 °C polycrystalline mullite board" is not a specification — a supplier can satisfy it with almost any grade in the range. A purchase order that gets you the board you actually need states all of the following: - Grade by Al₂O₃ content — 72–75 % for standard, 80 %+ for high-purity duty - Bulk density — 0.6–1.2 g/cm³, with a tolerance - Maximum continuous service temperature — not the classification temperature - Linear shrinkage limit — e.g. ≤1 % after 24 h at 1500 °C, with the test method named - Cold crushing strength minimum — typically ≥2 MPa for self-supporting boards - Dimensions and tolerances, plus any machining, drilling or cut-outs - Atmosphere — oxidising, reducing, vacuum, or alkali-bearing The three that matter most are continuous temperature, shrinkage limit, and density. Miss the shrinkage figure and you can receive a board that meets the temperature rating but loses 4 % of its volume on first heat-up, opening the gaps you were trying to avoid. For standard dimensions and available grades, see the polycrystalline mullite fiberboard product page. Failure Modes and Realistic Service Life PMFB is robust within its envelope but it has hard limits: - Above 1830–1850 °C mullite dissociates into alumina and a liquid silica phase. This is a structural failure, not gradual degradation, and it is why the 1900 °C figure is a survival peak. - Sustained service above 1700 °C accumulates shrinkage slowly. Design extra thickness to absorb it, or plan on a shorter campaign. - Strong alkalis and hydrofluoric acid attack the alumina content. - Iron-oxide-rich slag above 1500 °C forms low-melting eutectics with the board surface. - Mechanical impact — the board is rigid and relatively brittle; edges and corners chip, so handle and store it accordingly. Realistic expectations: in stable service at 1600 °C, PMFB typically runs 3–8 years. Above 1700 °C, or with frequent thermal cycling, plan for 1–3 years. Those numbers are comparable to dense brick and substantially better than any standard ceramic fiber board, which is the comparison that justifies the price. Installation and Handling Best Practices Surface Preparation - Mount on a flat, stable metal or refractory substrate - Leave an expansion gap of 3–5 mm per meter of lining at room temperature - Use stainless steel or ceramic anchors designed for the peak service temperature Cutting and Shaping - Cut with a carbide-tipped blade or fine-tooth band saw when green (unfired) - Wear PPE; fibers are classified as RCF and should not be inhaled - After first firing, the board surface sinters; subsequent machining requires diamond tooling Joint Treatment - Stagger joints between layers - Fill gaps with ceramic fiber bulk or rope of matching temperature grade - Avoid through-joints that create straight heat-loss paths When PMFB Is — and Is Not — the Right Choice Choose polycrystalline mullite board when: - Continuous operating temperature exceeds 1400 °C - Standard ceramic fiber board shrinks too much after heat-up - You need a rigid, self-supporting shape without heavy refractory mass - Chemical purity is important (semiconductor, lab, specialty metal furnaces) Consider alternatives when: - Temperature stays below 1200 °C — standard ceramic fiber board is lighter and cheaper - Severe abrasion or slag erosion is present — castables or dense brick may last longer - The application requires continuous service above 1700 °C — ultra-high-purity alumina or zirconia boards are needed Bottom Line Polycrystalline mullite fiber board is the practical bridge between lightweight ceramic fiber insulation and heavy refractory brick. With continuous service ratings of 1600–1700 °C and short-term tolerance to 1900 °C, it is the default choice for furnaces, laboratories, and high-temperature process equipment where standard fiber boards fail and dense brick is overkill. At Rosewool, we supply ISO 9001-, CE-, and SGS-certified polycrystalline mullite fiber board and related ultra-high-temperature insulation products for industrial, laboratory, and specialty applications worldwide. Contact us for grade selection, thickness recommendations, and installation guidance matched to your peak service temperature and cycle profile. Related products: Polycrystalline Mullite Fiberboard Related applications: Cement, Cryogenic Insulation FAQ: Q: What is the maximum continuous service temperature of polycrystalline mullite board? A: Most industrial grades are rated for continuous service at 1600–1700 °C. Short-term peaks up to 1800–1900 °C are possible, but sustained operation above 1700 °C accelerates grain growth and shrinkage. Q: How does polycrystalline mullite board differ from standard ceramic fiber board? A: Standard ceramic fiber board is made from glass-phase aluminosilicate fibers and is typically limited to 1000–1400 °C. Polycrystalline mullite board is fully crystalline mullite (3Al₂O₃·2SiO₂), giving it higher purity, lower shrinkage, and a service ceiling of 1600–1700 °C. Q: What is the typical bulk density and thermal conductivity of PMFB? A: Bulk density ranges from 0.6–1.2 g/cm³ depending on grade. Thermal conductivity at mean 800 °C is typically 0.15–0.35 W/(m·K), roughly one-third to one-half that of dense refractory brick. Q: Can polycrystalline mullite board be used in a 1900 °C furnace? A: Only for short-term exposure or thermal cycling. The 1900 °C figure is a survival limit, not a continuous operating temperature. For reliable service above 1700 °C, ultra-high-purity alumina or zirconia-based boards are recommended. Q: What are the main applications of polycrystalline mullite fiber board? A: Common uses include steel reheating furnaces, heat-treatment furnaces, ceramic and glass kiln linings, laboratory and tube furnaces, nuclear high-temperature test fixtures, hot isostatic press backup linings, and semiconductor crystal-growth furnaces. ### Aerospace & Defense Thermal Insulation Materials URL: https://www.rosetexwool.net/news/aerospace-defense-thermal-insulation-materials/ 2026-08-26 | Author: Rosetexwool Editorial | Category: industry insight Summary: Aerospace insulation compared across four sub-systems: flame diverters and launch pads, reusable rocket TPS, cabin fire barriers and burnthrough, plus five ways an aerospace spec differs. Aerospace insulation is defined by extremes. On the same platform, a designer may need to protect liquid-hydrogen fuel at −253 °C, manage avionics heat at 80 °C, and survive rocket-nozzle or re-entry temperatures above 2,000 °C. The material choice is rarely about a single property; it is the balance of thermal range, density, fire reaction, mechanical strength and lifecycle reliability. This article compares the four mainstream thermal insulation families used across the aerospace and defense supply chain — rock wool, ceramic fiber, glass wool and aerogel — and maps these aerospace insulation materials to their typical military and civilian applications. The data is drawn from published thermal-property tables, industry market reports and material qualification practice. Scope note. Aerospace insulation covers thermal, acoustic, fire and personnel-protection systems used across aircraft cabins and engine bays, launch-ground infrastructure, spacecraft thermal control and, where specified, fire-rated defense platforms. The term does not describe one product or one certification route: aerospace insulation materials range from low-temperature bagged blankets to reusable thermal protection systems, and aerospace thermal insulation is selected by service temperature, exposure duration, pressure and vibration, fire performance and maintainability — not by a single high-temperature ranking. Sub-system | Main boundary | Selection focus | On-board / cabin | Personnel areas, equipment bays, engine bays | Thermal management, smoke and toxicity, flammability, acoustics, replaceability | External surfaces and re-entry | Leading edges, windward and leeward surfaces, hot structures | Peak temperature, heat flux, cycles, radiation and structural coupling | Ground launch infrastructure | Flame diverters, flame trenches, launch pads, test stands | Short heat pulses, erosion, acoustic load, moisture and thermal shock | Defense and shipboard bulkheads | Fire divisions, penetrations, equipment enclosures | Fire integrity, back-face temperature rise, smoke and toxicity, mechanical load | Because aerospace insulation spans cryogenic storage, engine bays, re-entry surfaces and ground launch structures, the sections below are organised by thermal problem rather than by material name. 1. Material Properties at a Glance Material | Density (kg/m³) | Thermal Conductivity (W/m·K) | Service Temperature | Fire Rating | Notes | Rock wool | 80–250 | 0.035–0.050 | −50 °C ~ +1,000 °C | A1 / non-combustible | Mature, cost-effective, needs hydrophobic treatment | Ceramic fiber (aluminosilicate) | 80–250 | 0.030–0.060 | −50 °C ~ +1,260 °C | A1 / non-combustible | High-temperature, soft and formable, can sinter over time | Glass wool | 20–100 | 0.020–0.040 | −60 °C ~ +120 °C (short-term +400 °C) | A1 / non-combustible | Light, excellent acoustic absorption | Aerogel / microporous | 10–100 | 0.008–0.025 | −253 °C ~ +1,200 °C (carbon-based >3,000 °C) | A1 / non-combustible | Lowest thermal conductivity, thinnest envelope | Calcium silicate | Project data | Project data | Typical ≤650 °C (tobermorite) to ≤1,000 °C (xonotlite) | A1 / non-combustible | Rigid, dimensionally stable fire separation; listed separately — see note below | All four materials can achieve A1 non-combustible classification under EN 13501-1, which matters in aircraft, spacecraft and naval applications where fire load must be minimized. The real differentiator is the temperature–density–thickness trade-off. Why calcium silicate is listed separately. Its value is rigidity, dimensional stability and non-combustible fire separation rather than a headline maximum temperature. The typical engineering range depends on phase composition — roughly 650 °C for tobermorite grades and around 1,000 °C for xonotlite grades — and those figures describe material classification, not this page's main selection table. Density and conductivity for calcium silicate must be taken from project data; they are deliberately not added to the four-family table so that table keeps a single consistent source of numbers. 2. Aerospace Applications Aerogel: Ultra-Thin Across the Widest Range Aerogel's combination of extremely low thermal conductivity and wide temperature range makes it the material of choice when every millimetre and every gram count. - Cryogenic fuel systems. Liquid hydrogen at −253 °C and liquid oxygen at −183 °C both require insulation that stays effective at deep cryogenic temperatures. Aerogel blankets at 5–20 mm can replace 80–150 mm of conventional insulation, cutting boil-off and structural bulk. - Re-entry heat shields. Silica and carbon aerogels have been used in thermal-protection systems that see thousands of degrees during atmospheric entry, sometimes as a capture medium or as a lightweight ablative/insulative layer. - Satellite thermal control. Composite aerogel blankets in vacuum can reach effective conductivities below 0.010 W/(m·K), giving spacecraft designers tight control over equipment temperature without heavy multi-layer insulation. - Hypersonic vehicles. At Mach 5 and above, leading-edge temperatures rise rapidly. Carbon-aerogel and ceramic-aerogel composites provide thermal protection with far less weight than traditional tile systems. For deep-cryogenic pipework, the same design logic applies as described in our cryogenic pipe insulation guide: the vapor barrier is as important as the insulation itself. Ceramic Fiber: The High-Temperature Workhorse Ceramic fiber products dominate where sustained or short-duration heat exceeds 1,000 °C. - Rocket engines. Nozzle and combustion-chamber insulation use aluminosilicate or alumina fiber felts and blankets to protect structures from hot-gas streams. - Re-entry and reusable spacecraft. Rigid ceramic-fiber tiles and flexible blankets act as the primary thermal barrier on return vehicles. Some systems are qualified for 20+ reuse cycles with minimal mechanical degradation. - On-board high-temperature equipment. Around auxiliary power units, thermal batteries and propulsion-system hardware, ceramic fiber keeps adjacent avionics within limits. Rosewool supplies ceramic fiber bulk and blanket grades rated for continuous service up to 1,260 °C, suitable for engine-area insulation and high-temperature maintenance envelopes. Glass Wool: Cabin Comfort and Cryogenic Piping Glass wool is rarely the first choice for engine nozzles, but it plays a major role in two aerospace niches: - Aircraft cabin acoustic and thermal lining. Modern narrow-body and wide-body programmes use ultrafine glass-wool blankets to meet strict noise-reduction targets while keeping weight low. Some new-generation glass-wool systems achieve 55 dB attenuation at below 3 kg/m². - Cryogenic fuel lines. Hollow glass-microsphere and ultrafine glass-wool systems are used on liquid-hydrogen and liquid-oxygen transfer lines where low temperature, low conductivity and low weight are required. Because glass wool loses strength above roughly 120 °C in continuous service, it is normally paired with other materials when both thermal and acoustic control are needed. Rock Wool: Ground Support and Fire Safety Direct flight hardware use of rock wool is limited by density and moisture sensitivity, but it remains important in the aerospace ecosystem: - Ground test and launch facilities. Fire-rated partitions, engine-test-cell insulation and fuel-storage facilities use rock wool for its A1 rating and acoustic absorption. - Non-flight structural fill. In satellites and payloads where neither extreme temperature nor minimum weight is the driver, rock wool provides low-cost fire-safe fill. - Maintenance hangars and logistics buildings. Rock wool blanket systems protect aircraft storage and assembly areas from fire spread. 3. Ground and Launch Infrastructure: Flame Diverters, Test Stands and Sound Suppression Not every aerospace thermal problem is airborne. Before a vehicle leaves the ground, its exhaust plume strikes the launch mount or a flame diverter, is turned, and is routed away through a flame trench. That short event sets a completely different design target from re-entry: the structure does not need to survive forever, it needs to be inspectable and partially replaceable within hours or days. Flame diverter versus flame trench The two terms are often used interchangeably and should not be. The flame diverter is the first hot-structure component that changes plume direction, taking the brunt of impingement, particle erosion and thermal shock. The flame trench is the discharge path — a lined channel that carries the turned, expanded and mixed exhaust away from the vehicle, cabling, valves and personnel routes. Published launch-infrastructure literature describes the trench as a ground-level channel bisecting the pad, with the diverter built as an inverted-V steel structure carrying a refractory lining. That distinction matters for insulation because the two elements fail differently. A diverter panel is a localized, high-wear item designed to be swapped. A trench lining is a maintainable thermal boundary where failure usually starts at anchors, mortar joints and construction tolerances rather than in the refractory itself. A zoned composite system, not a single refractory block High-impingement, recirculation and particle-wear zones call for a dense refractory facing, an anchoring system, expansion and joint filler, an insulating backup layer and a structural substrate. Only in lower-erosion areas does it make sense to use ceramic fiber, rock wool or microporous layers as the primary low-conductivity element. Zone | Dominant load | Material logic | What the specification should say | Diverter / first impingement | High temperature, erosion, thermal shock | Dense refractory facing plus anchoring and removable liner | Panels are selected for localized erosion and thermal shock, then detailed as inspectable, replaceable modules | Flame trench walls and roof | Radiation, recirculation, gas erosion | Refractory masonry or castable plus insulating backup | The trench lining, not the plume path itself, is the maintainable thermal boundary | Launch pad and umbilical tower vicinity | Radiation, splash, acoustic load | Rigid cladding, sealing and water-tolerant systems | Launch pad insulation must remain functional after repeated wetting, heating and acoustic loading | Test stand thermal shielding | Steady or long-duration firing, nozzle plume | Accessible shielding with inspection clearances | A static-fire test stand trades ultimate reuse temperature for accessibility and controlled replacement | Water deluge zone | Water, steam, thermal cycling | Water-tolerant, drainage-compatible anchoring | Sound suppression water changes failure modes from pure heat to thermal cycling plus moisture transport | Exposure duration changes the material route. A published subscale solid-motor hot-fire test ran for about 20 seconds, with reported nozzle insulation exposure on the order of 5,000 °C for that specific test article. Both are test-condition values, not design constants: they cannot be converted into a continuous launch pad duty, and they must not be written into the material table above. What they legitimately show is that a local hot-face environment can sit far above the continuous service range of ordinary insulation — which is exactly why the hot face and the insulation layer are specified separately. If a firing extends from seconds into minutes, conduction depth, accumulated heat load, fastener expansion and backup temperature all increase, and the selection emphasis shifts from short-duration surface refractoriness to heat sinking, cooling and replaceable shielding. Sound suppression is a facility protection system first Water deluge is usually described as noise reduction, but for insulation it is a multi-physics boundary change. Water vaporizes near the plume, absorbing energy and forming a two-phase barrier, while the trench, roof or deflector geometry alters how acoustic energy propagates. Public technical references put near-field noise for large high-performance vehicles above 200 dB(A) around the base, and note that trench geometry, water injection and plume deflection all reduce the load at a given location; one documented case injected water for roughly 16 seconds before lift-off. Neither figure should be turned into a universal design input. What they establish is the order of magnitude: sound suppression water, steam and thermal cycling arrive together, and insulation in that zone has to survive wetting, draining, re-heating and re-wetting, not just peak temperature. Sound suppression protects the launch environment, but it also makes moisture-compatible anchoring, drainage and post-wet thermal-cycling performance part of the insulation specification. Water deluge is not an insulation layer in its own right. It reduces the load; it does not remove it. Materials still carry residual heat after the spray stops, dry-zone heat load, and the cumulative effect of repeated cycles. The failure chain runs backwards from the facing Plume impingement is maintainable because the system is zoned, not because the material is indestructible. A realistic chain looks like this: - Gas impingement and particle erosion wear the hot facing back. - Temperature gradients and thermal cycling initiate cracking. - Cracks accelerate erosion and let water in. - Anchors, mortar and joints loosen under cyclic loading. - Local spalling exposes the insulation layer and can create secondary debris. - Capacity is restored by zoned inspection, cleaning, patching or module replacement. Deliberate crack-instrumentation work on subscale motor testing exists precisely because heat, structure, acoustics and material defects cannot be analysed separately — one crack can change the temperature field, the flow boundary and mechanical stability at the same time. In launch pad design, inspectability and replaceability are as important as peak-temperature resistance: refractory linings are partitioned so that impingement-zone wear can be repaired without rebuilding the entire structure. Test stands are not launch pads A test stand is a controlled facility: instrumentation can be placed close to the article, drainage and access are designed in, and spare modules are held on site. That makes removable panels, water-cooled elements or active thermal management realistic. A launch pad operates under lift-off windows, recirculation risk, vehicle interfaces and turnaround pressure, so it favours zoned refractory facings and a fast inspection routine instead. Both share the same hot-face logic, and neither can be specified from a single peak temperature. 4. Aircraft Insulation Systems: Cabin, Cargo Bay and Engine Bay A transport aircraft carries insulation in three very different environments, and each one is specified on its own logic. Understanding the split is usually more useful than comparing material data sheets. Cabin: thermal-acoustic blankets with a fire-blocking layer The visible interior lining is only the cosmetic layer. Behind it sits a thermal-acoustic insulation blanket — usually an ultrafine glass-fibre batt at 6–16 kg/m³, encapsulated in a polymer film bag. It does three jobs at once: hold cabin temperature, cut airframe noise, and slow a fire long enough for passengers to get out. That last job is why transport-category rules require insulation inside the pressure vessel to pass a burnthrough-resistance test on top of the normal flammability checks. Modern blankets meet it with a fire-blocking layer: a thin high-silica or ceramic-fibre fabric, typically 0.3–2 mm thick and 100–300 g/m², placed on the outboard face of the bag. It contributes almost nothing to thermal performance. Its value is time — it resists flame penetration and holds the blanket together so a cabin fire does not reach the fuselage skin quickly. For the textile part of that assembly, ceramic fiber cloth in woven or needled form is the usual starting point, chosen for temperature capability and for how it behaves under flame rather than for conductivity. Cargo bay: fire containment and moisture management Cargo compartments are designed around containment, so the insulation there is paired with a liner that must hold a fire until the suppression system discharges. Two practical requirements dominate: the insulation must not hold water (condensation on the inside of the fuselage skin is constant in service), and it must be removable for inspection. Bagged blankets with sealed seams and deliberate drainage paths are the standard answer, and any absorbed moisture is treated as a weight and corrosion problem, not just a thermal one. Engine bay and APU zone: continuous high temperature Behind the firewall the criteria change completely. Insulation here sees 500–1,000 °C, continuous engine vibration, and fuel and hydraulic fluid contamination. Aluminosilicate ceramic fiber blanket and formed rigid parts are used, normally foil- or cloth-faced and clamped rather than bonded. Maintenance access drives the mechanical design: blanket sections have to be removed and refitted many times without losing thickness or compressing permanently. Zone | Temperature range | Typical insulation form | Governing requirement | Cabin | −55 °C to +85 °C | Bagged ultrafine glass wool, 6–16 kg/m³ | Burnthrough resistance, smoke and toxicity, areal weight | Cargo bay | Ambient to +200 °C | Bagged blanket, sealed seams, drainage | Fire containment, moisture management, inspectability | Engine bay / APU | 500–1,000 °C | Ceramic fiber blanket, formed parts, foil facing | Temperature, vibration, fluid resistance, removability | 5. Reusable Launch Vehicles and Re-entry Thermal Protection Reusability is often presented as a material substitution — a better tile replaces an ablative shield. In practice a thermal protection system is a zoned assembly, and reuse is an operating model, not a material property. Zoning is the selection logic Publicly documented reusable orbiter programmes divided the vehicle surface by temperature and structural function, and that zoning remains the clearest way to explain the choice: Zone | Typical system | Temperature boundary (historical vehicle) | Engineering meaning | Nose cap and wing leading edges | Reinforced carbon-carbon and hot structure | Highest temperature region | Shape retention, oxidation resistance, thermal cycling | Windward lower surface | High-temperature reusable surface insulation | About 650–1,260 °C | High radiative emission, insulation, thermal-shock resistance | Leeward and upper surfaces | Low-temperature reusable surface insulation | Below about 649 °C | Light weight, conformability, maintainability | Lower-temperature areas | Flexible reusable surface insulation | Below about 370 °C | Blanket coverage and joint control | Those boundaries describe one extensively documented winged reusable vehicle. They are useful as a working example of zoned re-entry design, not as a universal material boundary for every reusable rocket now flying. What rigid tiles actually trade In a reusable thermal protection system, rigid tiles achieve low conductivity through a porous ceramic body — historical figures put low-density tiles near 144 kg/m³ and higher-density tiles near 352 kg/m³, with thickness from roughly 12.7 mm to 127 mm depending on local heat load. Those are typical values for that vehicle, and they should not be back-filled into the four-family table in Section 1, which describes broad engineering ranges rather than one qualified product. Rigid tiles provide low conductivity through a porous ceramic body, but their reusable performance depends on coatings, strain isolation, attachment and damage inspection — not density alone. The costs are brittleness, attachment tolerance and joint maintenance. Tile fragility, water absorption and gap upkeep on the historical vehicle are the standard cautionary example: reusable never meant maintenance-free. Ablative versus reusable For a reusable rocket, the two routes solve different problems: - Ablative insulation consumes mass — decomposition, charring, melting or sublimation carry heat away. It suits a short, extreme heat pulse, a single mission, or a very high heat load where material consumption is acceptable. - Reusable systems retain the body and rely on low conductivity, radiative emission, hot structure and mechanical attachment, accepting inspection, repair and recertification after every flight. Ablative insulation is selected when a short, extreme heat pulse can be accepted as material consumption; reusable TPS is selected when inspection, repair and recertification are part of the operating model. Five boundary judgments follow from that: ablative keeps clear value for single, extreme, short-duration missions; multi-mission designs must weigh inspection, repair, certification and turnaround time together; the hottest local points may be hot structure rather than insulation; flexible insulation suits lower-temperature, conformable, large-area regions; and cycle life is only defined by heat flux, dwell time, peak temperature and the inspection regime together — never by a material name. Where the four families interface with TPS Family | Where it fits | Where it should not be assumed | Ceramic fiber | Mid-to-high temperature insulation, flexible blankets, composite layers | Leading edges and long-duration erosion surfaces | Aerogel / microporous | Low-to-mid temperature, space-constrained insulation | Carrying re-entry erosion on its own | Rock wool | Ground facilities, equipment bays, background bulkhead insulation | Certified cabin interiors or re-entry surfaces without project evidence | Glass wool | Low-temperature equipment insulation | Anything above its continuous service range | These are engineering interfaces, not equivalences. Reaching a temperature in the table does not qualify a material as flight TPS; thermal structure, attachment, environment, smoke and toxicity, and cycle verification still apply. For a reusable rocket, the practical conclusion is that a thermal protection system is specified as a maintained asset: flown, inspected, repaired where allowed, and recertified. No material should be described as infinitely reusable. 6. Aerospace vs Industrial Insulation: Five Differences That Change the Spec Engineers who move from a power plant or a petrochemical project into an aerospace programme usually find the thermal calculation is the easy part. Five other things decide the specification. - Weight is a design variable, not a cost variable. On a building, choosing 40 kg/m³ over 100 kg/m³ is mostly a price and handling decision. On an aircraft, every kilogram of insulation is payload or fuel that cannot be sold, so the spec is written in areal weight (kg/m² or g/m²), and the material is normally picked at the lowest density that still survives handling and vibration. - Outgassing matters as soon as there is a vacuum. Materials for spacecraft and high-altitude bays are screened for volatile content. The common screening method reports total mass loss (TML) and collected volatile condensable materials (CVCM), with acceptance limits in the order of 1.0 % TML and 0.10 % CVCM. Condensables are the real enemy: they redeposit on optics, sensors and thermal-control surfaces. - Fire performance is measured in minutes, not in classifications. A1 / non-combustible is the entry ticket, not the requirement. Aircraft rules add burnthrough resistance, heat release, smoke density and toxicity. An industrial ceramic fibre blanket with an excellent A1 rating can still fail an aviation fire spec because of its binder content or its smoke behaviour. - Vibration, thermal cycling and shedding. Airborne equipment is qualified against environmental standards that combine temperature and altitude cycling, vibration, humidity and salt fog in one sequence, and that series is the reference point across the industry. Insulation that is perfectly happy on a static duct can shed fibres, dust or binder after a few thousand hours of vibration — and loose conductive fibres in an avionics bay is a reliability problem, not a housekeeping one. - Traceability outruns performance. Aerospace programmes require batch-level certification, retained samples and a qualification tied to a specific manufacturing route. Changing a binder supplier can trigger requalification. In practice the buyer's question is rarely "which material performs best" but "which material can be supplied unchanged, with paperwork, for the next ten years". Our aerospace and defense application page shows where these materials land in a complete assembly. 7. Fire Barriers, Burnthrough Resistance and Fire-Blocking Layers Fire performance on an aircraft or a defense platform is a property of the complete assembly under a defined exposure, not of an insulation blanket's room-temperature conductivity. A fire barrier is therefore specified as an assembly, not as a blanket. Two different failure objects A cargo-compartment fire barrier and a cabin fire-blocking layer are trying to prevent different things: - The cargo boundary must delay flame, heat and smoke passing from the cargo volume into the cabin. Liners, floor panels and bulkheads form the barrier, and penetrations, joints, cable runs and duct openings are the weak paths. - Cabin materials — seat cushions, wall panels, textiles — need a fire-blocking layer or equivalent behaviour so that they do not contribute rapid flame spread, heat release or toxic smoke. Aviation material requirements cover vertical and horizontal burn behaviour, cargo-liner burnthrough and separate heat-release and smoke-density evaluation. The exact limits belong to the applicable aviation requirements and the approved assembly, not to a generic insulation data sheet. Burnthrough resistance describes how long a barrier resists through-penetration under a defined fire exposure, including edge sealing and substrate interaction; it is not an arbitrary maximum service temperature. Fire seals are tested with their neighbours A fire seal closes the path for heat, flame and smoke. Its durability depends on the material plus compression, joint geometry and substrate, which is why seal performance cannot be read off a fibre specification. Common engineering approaches include intumescent or ceramic fiber packing, high-temperature fabrics or blankets, sealants and coatings, and metal or composite protection layers. Aviation service adds compression set, vibration, fluid exposure, ageing and repeated removal. Fire seals perform as part of a joint: material alone cannot establish burnthrough resistance without substrate, compression and test conditions. Where calcium silicate fits Calcium silicate earns its place through rigidity and fire integrity rather than a headline temperature. It is a non-combustible, low-conductivity, dimensionally stable board that can carry load, accept fixings and hold shape after heating — which is why it is used for bulkheads, deck linings, fire-door cores, equipment enclosures and pipe or penetration divisions. Two cautions keep the specification honest: - Typical range is set by phase composition. Tobermorite grades are commonly quoted around 650 °C and xonotlite grades around 1,000 °C. These describe material classification and are deliberately kept out of the Section 1 table, so the page does not end up with two competing sets of numbers. Density and conductivity must come from project data. - Fire division is a system rating. Marine and platform practice evaluates a division such as an A-60 boundary for integrity and back-face temperature rise over a defined period. Calcium silicate board may form part of such a system where strength and insulation are both required — but that is a statement about the tested assembly, not about the board on its own. Calcium silicate is suited to fire-rated partitions and equipment enclosures where board strength, dimensional stability and post-fire integrity matter; the exact service temperature depends on composition, density and the approved system. Finally, a calcium silicate fire barrier should not be confused with ablative TPS. Re-entry protection works through external radiation, ablation or hot structure plus post-flight inspection; calcium silicate belongs to fixed passive fire protection. Both are thermal protection, but the load duration, structural function and acceptance route are different. 8. Harsh Environments: Vacuum, Vibration, Salt Fog and Radiation Beyond the airframe, aerospace thermal insulation is asked to survive conditions that never appear in a building services specification. - Vacuum and thermal cycling in orbit. With no air, convection disappears and radiation dominates. Multi-layer insulation — alternating low-emissivity films and thin spacers — is the standard answer, and the spacers must not compact under launch vibration or creep over a 15-year mission. Low Earth orbit adds atomic oxygen and ultraviolet exposure, both of which attack polymer films and organic binders first. - Salt fog and humidity on naval and coastal platforms. Shipboard installations are specified for long salt-spray exposure. Insulation with high water absorption loses thermal performance and, worse, drives corrosion under insulation on the pipe or bulkhead beneath it. Low-chloride hydrophobic grades and correctly sealed jacketing matter more here than the nominal conductivity figure. - Ionizing radiation. Spacecraft, high-altitude platforms and nuclear-facility installations all see ionizing radiation, which degrades organic binders and polymer facings long before it affects the inorganic fibre itself. The usual mitigation is to specify inorganic or very low-binder grades and to keep the organic content of the whole assembly — films, adhesives, sewing thread — as low as the design allows. - Ground support is not exempt. Test cells, launch structures and maintenance hangars carry the same fire and acoustic loads as the vehicle itself, which is where conventional rock wool blanket and board systems earn their place in the programme. For the nuclear side of this topic — reactor buildings, containment and radiation shielding — see our dedicated guide to aerospace and nuclear insulation. This section deliberately stops at the material-behaviour boundary so the two articles do not overlap. 9. Defense Applications Defense platforms push insulation in different directions: soldier survivability, missile speed, ship survivability and electromagnetic stealth. Aerogel in Defense - Personal protection. Thin aerogel layers integrated into cold-weather gear and vehicle interiors provide thermal protection without the bulk of legacy insulating materials. - Radiation shielding. The nanoporous structure can adsorb radioactive particulates, useful in nuclear facilities and certain naval systems. - Fire barriers. Composite aerogel blankets meet A1 non-combustible requirements while adding minimal weight to vehicle and ship compartments. Boron Nitride Fiber: High Heat Plus Electromagnetic Transparency Boron nitride fiber is not a mainstream commodity, but it is critical in specialized defense systems: - Missile radomes. Its low dielectric constant and loss tangent allow radar signals to pass through while the material survives the aerodynamic heating of high-speed flight. - Rocket nozzles. Woven boron nitride textiles tolerate gas temperatures above 2,800 °C in inert atmospheres. - Stealth and infrared suppression. Low thermal conductivity reduces infrared signature, while carbon-aerogel and BN composites can be tuned for radar absorption. Ceramic Fiber in Defense - Missile motor insulation. Ceramic fiber blankets and felts protect motor cases and nozzle structures from combustion temperatures. - Hypersonic thermal barriers. Reusable ceramic-fiber composites are being qualified for leading edges and nose cones on maneuvering hypersonic vehicles. - Ship and submarine systems. High-temperature exhaust and auxiliary-system insulation on naval vessels often use ceramic fiber for its corrosion and heat resistance. Glass Wool in Defense - Naval ships. Engine-room piping, bulkhead insulation and cabin partitioning on military vessels use glass wool for fire safety, acoustic control and thermal management. Systems are typically specified with high density, low water absorption and long salt-spray resistance. - Ground vehicles and shelters. Glass wool provides a cost-effective, non-combustible thermal and acoustic liner for command posts and transport shelters. 10. Market Trends and Supply-Chain Considerations The global aerospace insulation market is estimated at roughly USD 1.0–1.6 billion in 2025, with projected compound annual growth of 5–8.7 % through the early 2030s. Key drivers include: - Commercial aviation recovery and fleet renewal programmes. - Reusable rockets and reusable launch vehicles, which multiply the demand for durable thermal-protection materials. - Hypersonic programmes, both civil research and defense, pushing materials above 1,500 °C. - Green-aviation targets, encouraging lighter insulation that improves payload and fuel efficiency. Aerogel and ceramic-matrix composites are expected to grow faster than the overall market, increasing their combined share from roughly 12 % to more than 25 % by 2032. Supply-Chain Notes Recent tariff actions have affected several raw-material categories, including certain fiberglass fabrics and high-silica textiles. For export-oriented projects, engineers and buyers should: - Qualify second-source suppliers early. - Consider regional production or bonded warehousing for sensitive programmes. - Document material traceability and certification from the start. 11. How to Select an Aerospace or Defense Insulation Material Aerospace thermal insulation is selected in the same order as any other engineering material: use temperature as the first filter, then refine by weight, space and functional requirements. The difference is that aerospace insulation materials are also filtered by exposure duration, certification route and how often the part has to come off for inspection. Temperature Regime | Preferred Material | Typical Use | > 1,200 °C sustained | Alumina / SiC ceramic fiber, boron nitride | Rocket nozzles, leading edges, re-entry tiles | 500 °C – 1,200 °C | Ceramic fiber, aerogel composite | Engine compartments, APU zones, exhaust systems | −150 °C – 120 °C | Glass wool, aerogel | Cabin liners, cryogenic lines, fuel systems | < −150 °C | Aerogel / microporous, hollow-glass microspheres | Liquid-hydrogen storage, deep-space probes | Multifunction (thermal + acoustic + fire) | Engineered composites / layered systems | Aircraft cabin, naval ships, crew compartments | When the application requires more than one function — for example thermal control plus radar transparency plus ablation resistance — the answer is almost always a composite rather than a single material. The same logic applies to fire: where a fire barrier is required, the qualified object is the assembly — facing, insulation, sealing and substrate — not a single blanket. 12. Future Trends Four trends are reshaping aerospace and defense insulation: - Lower conductivity at lower weight. Silica aerogels are targeting conductivities below 0.005 W/(m·K), while new ceramic-fiber felts maintain strength above 1,500 °C. - Scalable manufacturing. Ambient-pressure drying for aerogel and green chemistry for boron nitride fiber are expected to reduce cost and environmental impact. - Reusable systems. Reusable rocket programmes are asking for thermal-protection materials that survive 20+ flight cycles with predictable degradation. - Digital qualification. AI-assisted modelling of material microstructure is shortening the time from lab sample to flight qualification. 13. Conclusion Aerospace insulation is not a one-material market. Rock wool, ceramic fiber, glass wool and aerogel each occupy a distinct zone in the temperature–weight–cost map. The right specification usually combines materials: aerogel for the thinnest cryogenic envelope, ceramic fiber for engine and re-entry heat, glass wool for cabin acoustic and thermal comfort, and rock wool for ground-support fire safety. Rosewool manufactures ISO 9001-, CE- and SGS-certified insulation materials spanning rock wool, ceramic fiber, glass wool and nano/microporous insulation, with a supply base established in 1982. For project-specific material selection, thermal calculations or certification support, contact our technical team with your operating temperature, weight target and applicable standard. For related reading, see our guides on non-combustible A1 fire-rated insulation systems and aerogel versus traditional insulation. Related products: Ceramic Fiber Plus Blanket, Ceramic Fiber Paper Related applications: Aerospace & Defense FAQ: Q: What insulation is used for rocket engines? A: Rocket engines typically use ceramic fiber blankets or felts for nozzle and combustion-chamber insulation because they withstand sustained temperatures above 1,000 °C. For cryogenic fuel tanks, aerogel and microporous insulation are preferred for their extremely low conductivity at −253 °C. Q: Why is aerogel used in spacecraft? A: Aerogel offers the lowest thermal conductivity of any solid insulation and remains effective across a very wide temperature range, from deep cryogenic to over 1,200 °C. This lets spacecraft designers save weight and volume on thermal protection and fuel-system insulation. Q: What is the best insulation for cryogenic fuel tanks? A: Aerogel blankets and microporous insulation are the leading choices for liquid-hydrogen and liquid-oxygen systems because a 5–20 mm layer can replace 80–150 mm of conventional insulation. Hollow-glass-microsphere systems are also used on some transfer lines. Q: How do thermal protection tiles work on re-entry vehicles? A: Re-entry tiles are made from rigid ceramic-fiber or silica-fiber composites with very low thermal conductivity. They absorb and radiate away frictional heat while keeping the vehicle structure within safe temperatures. Reusable systems are qualified for multiple flights. Q: What certifications matter for aerospace insulation? A: Key certifications include EN 13501-1 fire reaction (A1 non-combustible preferred), applicable aviation flammability requirements where required, ISO 9001 quality systems, and project-specific material traceability. Military programmes may add defense-standard qualification and salt-spray testing. Q: What insulation materials are used in aircraft cabins? A: Cabin insulation is a bagged thermal-acoustic blanket, usually ultrafine glass fibre at 6–16 kg/m³ sealed inside a polymer film, with a fire-blocking fabric layer on the outboard face. It has to deliver thermal control, noise reduction and burnthrough resistance at the same time. Where temperatures rise above what glass wool can handle — engine bays and APU zones — ceramic fiber replaces it. Q: What is a fire-blocking layer in aircraft insulation? A: A fire-blocking layer is a thin high-silica or ceramic-fibre fabric, typically 0.3–2 mm thick and 100–300 g/m², fitted to the outside of the insulation bag. It adds almost no thermal value on its own. Its job is to resist flame penetration and hold the blanket together, so a cabin fire takes much longer to reach the fuselage skin and the structure keeps its integrity. Q: How is aerospace insulation different from industrial insulation? A: Five things change the specification: weight is written as areal mass rather than bulk density; outgassing is screened for vacuum service; fire acceptance includes burnthrough resistance, smoke density and toxicity rather than non-combustibility alone; the material must survive vibration and thermal cycling without shedding fibres; and batch-level traceability is mandatory for the life of the programme. Q: Which insulation is used in aircraft engine bays? A: Aluminosilicate ceramic fiber blanket and formed rigid parts rated for continuous service up to 1,260 °C, normally foil- or cloth-faced and held with clamps rather than adhesive. The design is driven less by conductivity than by temperature, vibration, resistance to fuel and hydraulic fluid, and the need to remove and refit sections during maintenance without losing thickness. Q: Do aircraft insulation materials need to be tested for outgassing? A: Yes, for any vacuum or high-altitude application. Materials are screened for total mass loss (TML) and collected volatile condensable materials (CVCM), with acceptance limits commonly around 1.0 % TML and 0.10 % CVCM. The reason is not the material itself but what it releases: condensables redeposit on optics, sensors and thermal-control surfaces and degrade them over time. Q: What does "aerospace insulation" cover? A: Aerospace insulation covers thermal, acoustic, fire and personnel-protection systems across four sub-systems: on-board cabins and equipment bays, external surfaces and re-entry thermal protection, ground launch infrastructure such as flame diverters and test stands, and fire-rated defense or shipboard bulkheads. The term does not imply a single certification route — each sub-system is qualified against its own requirements. Q: How is a flame diverter different from a flame trench? A: A flame diverter is the first hot-structure component that changes plume direction, taking impingement, particle erosion and thermal shock directly. A flame trench is the discharge path — a lined channel that carries the turned and expanded exhaust away from the vehicle. Diverter panels are designed as localized, replaceable wear items, while the trench lining is a maintainable thermal boundary where failure usually starts at anchors and joints. Q: Why does sound suppression change insulation requirements? A: Water deluge changes more than noise. It alters temperature, pressure, acoustic and moisture boundaries at once: water vaporizes near the plume, forms a two-phase barrier, and then leaves the insulation wet. Materials in that zone must survive thermal shock, repeated wetting and drying, drainage provision and moisture-compatible anchoring — not just peak temperature. Q: Can reusable rockets reuse the same insulation indefinitely? A: No. Reusability is an operating model, not a material property. A reusable thermal protection system is flown, inspected, repaired where the programme allows, and recertified. Cycle life is defined by heat flux, dwell time, peak temperature and the inspection regime together, so no insulation should be described as infinitely reusable. Q: When is ablative insulation preferred over reusable TPS? A: Ablative insulation is preferred when a short, extreme heat pulse can be accepted as material consumption — a single mission, a very high heat load, or a case where carrying inspection and repair capability costs more than the material. Reusable thermal protection is preferred when inspection, repair and recertification are already part of the operating model. Q: Does calcium silicate replace ceramic fiber? A: Not on a temperature ranking. Calcium silicate provides rigidity, dimensional stability and non-combustible fire separation for bulkheads, deck linings, fire-door cores and equipment enclosures, while ceramic fiber serves mid-to-high temperature insulation and flexible blankets. Their typical ranges come from different tests, so any substitution has to be justified by the complete assembly rather than a maximum-temperature figure. ### Aerogel vs Traditional Insulation: Thickness & Cost URL: https://www.rosetexwool.net/news/aerogel-vs-traditional-insulation-thickness-cost/ 2026-08-25 | Author: ding li | Category: industry insight Summary: Aerogel vs rock wool, ceramic fiber and PU foam: compare thickness, upfront cost and lifecycle payback for industrial insulation. Aerogel is no longer a laboratory curiosity. In the last decade it has moved from aerospace prototypes into petrochemical pipelines, high-performance building envelopes and electric-vehicle battery packs. The reason is simple: aerogel insulation delivers the same thermal resistance as conventional materials in a fraction of the thickness, often with a lifecycle cost that is lower than the alternatives. This article compares aerogel with the most common traditional insulation materials — rock wool, ceramic fiber and polyurethane (PU) foam — across two dimensions that matter most to engineers and procurement teams: thickness and cost. The data is drawn from field projects, published thermal-property tables and Rosewool's own work with high-temperature and cryogenic insulation systems. 1. Thermal Performance and Thickness Comparison The starting point for any insulation comparison is thermal conductivity. The lower the value, the less material is needed to achieve a target heat loss or surface temperature. Material | Thermal Conductivity (W/m·K) | Typical Thickness for Equivalent Performance | Max Service Temperature | Aerogel blanket | 0.017 – 0.020 | 5 – 10 mm | –200 °C ~ 650 °C | Ceramic fiber blanket | 0.036 – 0.050 | 50 – 100 mm | 1,000 °C ~ 1,260 °C | Rock wool board / blanket | 0.030 – 0.050 | 80 – 120 mm | 600 °C ~ 700 °C | Polyurethane foam | 0.021 – 0.041 | 50 – 100 mm | –40 °C ~ 120 °C | A practical example makes the difference clearer. A hot-oil pipeline that would traditionally be insulated with 180 mm of ceramic-fiber pipe covering plus metal cladding can often be redesigned with 20 mm of silica aerogel blanket backed by 30 mm of rock wool blanket — a total thickness reduction of roughly 60 %. That frees up walkway space, simplifies pipe supports and reduces cladding cost. Why Aerogel Is So Much Thinner Aerogel's advantage comes from its nano-porous structure: - Pore size is below the mean free path of air, so gas-phase convection and conduction are strongly suppressed. - Solid conduction is limited because the silica network touches at very few points. - Infrared radiation can be reflected with opacifier additives, further cutting radiative heat transfer at elevated temperatures. The combined effect is a material that conducts 50 %–80 % less heat than conventional insulation of the same thickness — or, equivalently, needs only one-fifth to one-half the thickness for the same performance. Temperature and Moisture Stability Aerogel also holds its performance in conditions that degrade traditional materials: - High-temperature stability: linear shrinkage below 650 °C is negligible, whereas organic foams degrade and some mineral-fiber products compact over time. - Hydrophobic behavior: water absorption is typically below 1 %, so the thermal conductivity does not spike after rain, steam leaks or wash-down cycles the way it does with open-cell foams. For applications where both thermal performance and space are constrained — such as cryogenic pipe systems — this stability is a decisive advantage. Where the application calls for a rigid pressed board rather than a flexible blanket, our ultra-thin nano microporous board guide covers the same thickness question from the board side. 2. Upfront Cost versus Lifecycle Cost There is no way around it: aerogel has a higher purchase price per square metre than commodity insulation. The question is whether the higher first cost is recovered through operating savings. Typical Installed Cost Ranges Application | Traditional Solution | Aerogel-Based Solution | Petrochemical pipeline | Mineral wool — baseline cost | Aerogel composite — roughly 1.8 times mineral wool | Building exterior wall | Rock wool system — higher installed cost | Aerogel composite panel — lower installed cost | EV battery pack | IXPE / MPP foam — lowest first cost | Aerogel thermal barrier — highest first cost | Note: regional pricing varies significantly. Chinese domestic supply chains are currently the most competitive, while North American projects may carry a 25 %–30 % premium related to local manufacturing and policy incentives. What Drives the Higher First Cost - Raw materials account for roughly 48 % of aerogel cost. Silica precursors and specialized opacifiers are more expensive than basalt or slag fibers. - Drying energy is the next largest factor. Supercritical CO₂ drying is energy-intensive, although new ambient-pressure drying routes are cutting this by 30 % or more. - Scale effects are still maturing. Rock wool and PU foam are produced in vast commodity volumes; aerogel is scaling fast but has not yet reached the same output levels. Lifecycle Economics: Where the Payback Appears A 120 km crude-oil pipeline retrofit is a useful reference. The aerogel solution required a higher initial investment but reduced steam consumption by 18,500 tonnes per year, and the operating savings recovered that premium with a payback period of approximately 4.5 years, with continued savings for the remaining 15–20-year service life. A 5,000 m² building-envelope comparison showed a similar pattern: Solution | First Cost | Mid-Life Maintenance | 25-Year Total | Aerogel composite | Highest | Minimal | Lowest | Rock wool | Lowest | Moderate | +40 % vs aerogel | PU foam | Middle | Moderate | Higher than aerogel | In energy-intensive systems, aerogel usually wins on total cost of ownership even when it loses on purchase price. 3. Application-Specific Recommendations Petrochemical Pipelines - High-temperature lines above 400 °C: aerogel is usually the best economic choice because the energy savings repay the premium in 2.8–4.5 years. - Medium-temperature lines below 400 °C: consider an aerogel + ceramic fiber composite to balance cost and performance. - Corrosive environments: specify hydrophobic aerogel with compatible cladding to avoid the water-ingress failures common in mineral wool systems. - Cryogenic and LNG duty: this is where the thickness premium pays back fastest, because at these temperatures foam and foam glass need two to three times the depth. See the cryogenic insulation applications guide for the full scenario split. Building Envelopes - High-performance or net-zero buildings: aerogel's thin profile maximizes usable floor area and often simplifies detailing around windows and balconies. - Fire-critical facades: aerogel composites can achieve A1 non-combustible ratings, matching the safest mineral wool systems. - Retrofit projects: the thinness minimizes the impact on existing floor plans and facade depths. Electric Vehicle and Energy Storage Batteries Thermal runaway containment is now a regulated requirement in many markets. Aerogel thermal barriers: - Are as thin as 1 mm, preserving pack energy density. - Can extend the time before cell-to-cell propagation from minutes to 30+ minutes. - Meet A1 / non-combustible requirements without the toxic smoke associated with some polymer foams. For large battery-energy-storage systems, this safety margin often justifies the higher material cost on its own. 4. Cost Outlook and Market Trends The aerogel industry is scaling rapidly. Global production capacity is projected to exceed 330,000 m³ per year in the near term, with Chinese producers driving much of the expansion. As a result: - Raw-material costs are expected to fall by roughly 30 % as precursor supply diversifies. - New drying technology is cutting energy use by 30 %. - EV-battery aerogel unit prices are forecast to fall further by 2027. These trends mean the economic crossover point between aerogel and traditional insulation is moving into more mainstream applications every year. 5. How to Choose Use this short decision tree when specifying insulation: - Is space constrained? If yes, short-list aerogel. - Is the operating temperature above 400 °C or below –100 °C? Aerogel's stability becomes more valuable. - Is moisture or corrosion present? Hydrophobic aerogel reduces maintenance. - Will the asset operate for more than 10 years? Lifecycle savings usually outweigh the higher first cost. - Is first cost the only selection criterion? A conventional material may still be appropriate. Rosewool supplies a range of high-performance insulation products including nano insulation board, rock wool blanket, ceramic fiber bulk and glass wool blanket. All products are backed by ISO 9001, CE and SGS certifications and manufactured from a supply base established in 1982. For project-specific thickness and cost estimates, contact our technical team with your operating temperature, pipe diameter or wall assembly details. For a decision table that also weighs microporous board and vacuum panels against aerogel, see our nano vs aerogel vs microporous selection guide. FAQ: Q: Is aerogel insulation better than rock wool? A: Aerogel is thinner and has lower thermal conductivity, making it ideal where space is limited. Rock wool remains cost-effective for standard high-temperature applications and is often the better choice when first cost is the main driver. Q: Why is aerogel more expensive than traditional insulation? A: The higher cost comes from silica precursor raw materials (about 48 % of cost) and energy-intensive drying processes, especially supercritical CO₂ drying. New ambient-pressure drying and larger production volumes are rapidly narrowing the gap. Q: How thin can aerogel insulation be? A: For many industrial applications, 5–10 mm of aerogel blanket can replace 50–100 mm of mineral wool or ceramic fiber. In EV batteries, aerogel thermal barriers as thin as 1 mm are in commercial use. Q: What is the typical payback period for aerogel insulation? A: In energy-intensive systems such as hot pipelines, payback periods of 2.8–4.5 years are common. In building envelopes, aerogel often has the lowest 25-year total cost despite a higher first cost. Q: Can aerogel completely replace rock wool or ceramic fiber? A: Not always. Aerogel excels where space, weight or moisture resistance is critical. For very high temperatures above 650 °C, ceramic fiber is still required. A composite design often gives the best balance of performance and cost. ### Rosewool Insulation Featured in Architect Today on Sustainable Design URL: https://www.rosetexwool.net/news/rosewool-featured-architect-today-sustainable-building-design/ 2026-08-25 | Author: Rosetexwool Editorial | Category: company news Summary: Rosewool's Technical Director ding li was featured in Architect Today's expert roundup on practical sustainability tradeoffs in building design. Rosewool Insulation Refractory Co., Ltd. is pleased to share that our Technical Director, ding li, was featured among industry experts in Architect Today's expert roundup, "Choosing Practical Sustainability Tradeoffs in Building Design" (published August 24, 2026). Our Insight: Specify Mineral Wool for the Building Envelope In the article, ding li contributed perspectives on one of the highest-impact, lowest-complexity choices available to building designers: specifying high-density rock wool (A1 non-combustible mineral wool) insulation for the building envelope and mechanical systems. "The simplest sustainability win we specify is upgrading to A1-class rock wool insulation. It turns the building envelope from a thermal liability into a 30-plus-year asset, while also removing a major fire-safety risk from the project." Based on Rosewool's work with industrial and commercial projects since 1982, buildings using A1 non-combustible mineral wool insulation typically achieve 20–40% lower HVAC energy intensity over a 25-year lifecycle compared with lower-performance alternatives. The upfront cost delta is usually small relative to the total envelope budget, while the material is made with recycled content, lasts the lifetime of the building, and removes the need for mid-life replacement. Read the Full Feature The full expert roundup — covering door sealing, durable flooring, HVAC sizing, moisture control, thermal mass, and mineral wool — is available on Architect Today: Choosing Practical Sustainability Tradeoffs in Building Design — Architect Today About Rosewool Insulation Refractory Co., Ltd. Founded in 1982, Rosewool manufactures and supplies high-temperature and fire-safe insulation materials for industrial, commercial, and building applications worldwide. Our product range includes rock wool insulation, ceramic fiber, calcium silicate board, glass wool, and nano/microporous insulation. All products are backed by ISO 9001, CE, and SGS certifications. Explore our building insulation applications or read our guide to non-combustible A1 fire-rated insulation systems. Learn about our green building insulation applications for low-carbon and sustainable building projects. Related products: Rockwool Insulation Slabs — Rock Wool Board Related applications: Building, Green Building & Retrofit ### Glass Wool Blanket: Specifications & Buying Guide (2026) URL: https://www.rosetexwool.net/news/glass-wool-blanket-specifications-buying-guide/ 2026-08-24 | Author: Rosetexwool Editorial | Category: industry insight Summary: A practical guide to glass wool blanket specifications, performance parameters, application selection, and supplier evaluation for industrial insulation buyers. Quick answer: A glass wool blanket is a flexible roll of inorganic glass fibers bonded with a thermosetting resin. It offers thermal conductivity as low as 0.032 W/(m·K), A1 non-combustible fire class under EN 13501-1, and continuous service temperatures up to 350–400 °C depending on grade, with short-term peaks to 450 °C. It is the material of choice for HVAC ductwork, acoustic partitions, industrial pipe wrapping, and low-to-medium temperature equipment where low weight and easy handling matter. When buyers search for a "glass wool blanket," they are usually comparing specifications, not brands. They need to know whether the density, facing, and temperature rating fit the job, how it differs from rock wool, and what certifications to demand. This guide covers the specification parameters that actually determine performance, maps common applications to the right product grade, and gives a supplier-evaluation checklist that works across ASTM C553, EN 13162, and GB/T 13350 projects. What Is a Glass Wool Blanket? A glass wool blanket is manufactured by melting silica sand, recycled glass, limestone, and dolomite at temperatures above 1,300 °C, then centrifuging or blowing the molten glass into fine fibers. A small amount of binder is added to hold the fibers in a resilient, rollable mat. The result is a lightweight, flexible insulation material with a fiber diameter typically between 4 µm and 9 µm and a density range from about 10 kg/m³ to 80 kg/m³ for blankets. The key performance advantages are: - Low thermal conductivity — among the lowest of mineral insulation products at room temperature. - A1 non-combustible — inorganic fibers do not sustain combustion; see our A1 fire-rating guide for the test details. - Good acoustic absorption — open fiber structure absorbs mid-to-high frequency noise. - Lightweight and soft — easy to cut, wrap around pipes, and install in cavity walls. - Chemically stable — does not rot, is resistant to most industrial atmospheres, and is non-corrosive to steel when dry. The trade-off is service temperature. Standard glass wool is rated for continuous use up to about 350 °C; pre-cured high-temperature grades extend continuous duty to roughly 400 °C with short peaks to 450 °C. Above that, rock wool blanket or ceramic fiber blanket is the safer choice. Glass Wool Blanket Types and Specifications By density Grade | Typical density | Best use | Light duty | 10–24 kg/m³ | Ceiling voids, lightweight HVAC ducts, acoustic panels | Standard | 24–48 kg/m³ | Industrial pipe wrapping, vessel insulation, wall cavities | Heavy duty | 48–80 kg/m³ | External walls, equipment with higher mechanical load, pipe supports | Higher density improves compressive resistance and dimensional stability but adds weight and cost. For pipe wrapping, 32–48 kg/m³ is the most common range because it balances thermal performance with ease of bending around elbows. By facing Facing | Function | Typical application | Unfaced | Lowest cost, dry environments | Indoor cavities, equipment behind cladding | Aluminum foil | Moisture barrier, reflects radiant heat | HVAC ducts, pipe insulation | Fiberglass cloth | Higher tensile strength, abrasion resistance | Industrial equipment, frequent maintenance access | Reinforced foil / PVC | Tear resistance, vibration tolerance | Underground utilities, marine engine rooms | The facing must be checked against the fire classification. A plain glass wool core may be A1, but a polymer-coated facing can downgrade the finished product. Always request the classification report for the complete composite. By temperature rating Type | Continuous service | Peak exposure | Notes | Standard glass wool blanket | -50 °C to 350 °C | 400 °C short-term | Most common industrial grade | High-temp glass wool blanket | -50 °C to 400 °C | 450 °C short-term | Pre-cured binder; no glass wool grade survives 500 °C | For continuous duty above 400 °C, switch to rock wool (up to ~750 °C) or ceramic fiber (above 800 °C). The article "What Temperature Can Rock Wool Withstand?" explains when that transition makes sense. Key Performance Parameters (Specification Table) The following table lists the parameters a buyer should verify on a test report. Values shown are typical for a quality industrial glass wool blanket meeting ASTM C553 / EN 13162 / GB/T 13350-2017. Parameter | Typical range | Test standard | Why it matters | Density | 10–80 kg/m³ (blanket) | ASTM C303 / GB/T 5480 | Determines thermal and mechanical performance | Thermal conductivity | 0.032–0.045 W/(m·K) at 25 °C | ASTM C518 / GB/T 10294 | Lower λ = better insulation and lower energy loss | Max service temperature | 350–450 °C | ASTM C411 / GB/T 17430 | Must exceed operating temperature | Water repellency | ≥ 98% | GB/T 10299 / ASTM C1101 | Controls moisture uptake in humid environments | Moisture content | ≤ 1.0% | GB/T 13350 | High moisture raises thermal conductivity | Fire class | A1-s1,d0 (EN 13501-1), Class A (ASTM E84) | EN ISO 1182, EN ISO 1716 | Confirms non-combustibility for fire-rated systems | Compression recovery | ≥ 85% at 70 °C | ISO 13153 / ASTM C165 | Keeps thickness under vibration and thermal cycling | Shot content | ≤ 1.0% (fine fiber) | GB/T 5480 / ASTM C1335 | Lower shot = better fiber uniformity and less dust | Acoustic absorption coefficient | 0.7–1.0 at 1,000–4,000 Hz | ASTM C423 / ISO 354 | Important for noise-control applications | Thermal conductivity is the headline number. A blanket with λ = 0.032 W/(m·K) transfers roughly 30% less heat than one at 0.045 W/(m·K) for the same thickness. Over a plant operating 8,000 hours per year, that gap can mean measurable fuel or electricity savings. Shot content is a hidden quality indicator. Shot is the coarse, un-fiberized glass residue left during production. Excessive shot reduces flexibility, lowers thermal performance, and creates dust during installation. Premium centrifugal glass wool keeps shot content well below 1% — for how the centrifugal line controls fibre diameter, shot and roll recovery, see our centrifugal glass wool manufacturing guide. Glass Wool Blanket Sizes, Rolls and Compression A glass wool blanket order is specified by width, length, thickness and density — usually in that order — and most of the dimensional questions buyers ask are really roll-format questions. Density grade | Typical thickness | Roll format | Light duty, 10–24 kg/m³ | 25–100 mm | Wide low-density rolls for ceilings, ducts and acoustic lining | Standard, 24–48 kg/m³ | 25–100 mm | Standard rolls and cut strips for pipe wrap and vessel insulation | Heavy duty, 48–80 kg/m³ | 25–75 mm | Denser, shorter rolls where mechanical strength matters | Sheet width is commonly 1200 mm, with narrower strips cut for pipe wrapping; roll length is set by thickness, density and the compression ratio, so it varies by manufacturer — confirm the supplied roll length in writing rather than assuming a standard. Compression packaging is part of the specification. Glass wool blankets for transport are usually vacuum-compressed to roughly one-fifth to one-eighth of their unpacked volume, which is why freight and storage cost so much less than for rigid board. The compression ratio depends on density: light 10–16 kg/m³ rolls compress hardest, while heavy 48–80 kg/m³ blankets compress least. After the wrapping is cut, let the roll recover in a dry indoor space — most of the nominal thickness returns within 24–48 hours, and recovery slows sharply in damp or cold storage. If the material will be stored for weeks, open one roll and measure the recovered thickness before the full batch goes to site; the rebound check belongs in goods-inward inspection, not at the wall. Because blankets are compressed and boards are not, the two formats carry different dimensional-tolerance systems — see our rigid glass wool board selection guide before mixing blanket and board in one specification. Factory catalogues sometimes list the same product as glass wool felt or glass wool roll; the material is identical to the centrifugal glass wool blanket described on this page. How to Choose Glass Wool Blanket by Application HVAC ducts and air handling Use light-to-medium density (24–48 kg/m³) with aluminum foil facing. The foil acts as a vapor barrier and reflects radiant heat. Confirm the composite meets local HVAC fire codes, such as UL 181 / NFPA 90A in North America or EN 13501-1 in Europe. Industrial pipe and vessel wrapping Medium density (32–48 kg/m³) is the standard. For straight runs, cut the blanket to the calculated thickness and secure with bands or wire. At elbows and flanges, the flexibility of the blanket is a major advantage over rigid boards. If the pipe operates above 350 °C, consider rock wool instead.For the full decision — when the flexible form gives way to board, and where a pre-cut batt beats both — see our glass wool board vs blanket vs batt selection guide. Building wall and roof insulation For metal building roofs or curtain-wall cavities, choose 32–64 kg/m³ with reinforced foil facing. The higher density resists wind loading and foot traffic during installation. Pair with a continuous air barrier to prevent convective heat loss. Underground utilities and tunnels Specify a water-repellent grade (≥ 98%, preferably ≥ 99%) with a reinforced foil or PVC jacket. Underground humidity can saturate standard glass wool and collapse its thermal performance. For deeper treatment of moisture behavior, see our article "Is Glass Wool Blanket Waterproof?". Acoustic enclosures and machine rooms Use a medium-density blanket (48–80 kg/m³) unfaced or with a perforated facing that lets sound reach the fibers. Target an absorption coefficient ≥ 0.7 across the frequency range of the noise source. For NRC and αw data by density grade, and how they compare with rock wool panels, see our glass wool acoustic insulation guide. New energy and battery storage (BESS) Battery compartments and power conversion skids need A1-s1,d0 insulation with low smoke and no toxic emissions. Glass wool qualifies on fire class, but only if the facing and adhesive are also A1. Verify the full composite classification. If the question is broader than blanket — how the types of glass wool compare with rock wool on temperature, density and fire duty — start with our seven-difference glass wool and rock wool guide. Buying Guide: What to Verify from a Supplier Certifications and test reports Demand documentation for the exact product SKU you will receive, not a generic family certificate. Essential items include: - ISO 9001 quality-management certification - CE marking for European projects (DoP with declared thermal conductivity and fire class) - Third-party test reports for thermal conductivity, density tolerance, fire class, and water repellency - Factory production control (FPC) records or batch test reports for large orders Density tolerance A reputable supplier controls density within ±10% of nominal; high-precision lines hold it within ±5%. Large density variation leads to uneven thermal performance and poor fit on pipes. Binder and emission credentials For indoor or HVAC use, confirm low-VOC or formaldehyde-free binder options. Ask for an SGS or equivalent report on TVOC emissions if the project has indoor-air-quality requirements. Delivery and support - Lead time for standard densities and thicknesses should be stated in writing. - MOQ and cut-roll policy matter for small-to-medium MEP projects. - Technical support should include installation guidance, especially for pipe wraps and penetration seals. - Warranty period — 8 years is common; 10–15 years is available from manufacturers with strong quality systems. Packaging and handling Insist on moisture-resistant packaging. Compressed rolls save freight but must rebound to full thickness after unpacking; test a sample roll if the product will be stored on site for more than a few weeks. Common Mistakes to Avoid - Specifying glass wool above its continuous temperature limit. Above roughly 400 °C the binder degrades progressively and the blanket loses thickness — no glass wool form survives 500 °C. Use rock wool or ceramic fiber for hot zones. - Ignoring the facing. A foil facing changes the fire classification and the vapor-barrier performance. Match facing to environment. - Buying on price alone. Low-cost rolls often have high shot content, wide density tolerance, and poor recovery after compression. - Forgetting about compression. In pipe supports, heavy valves, or vibration zones, low-density blanket can compact. Use higher density or a rigid board at support locations. - Skipping the composite fire report. A core may be A1, but the finished roll with facing and adhesive may not be. For the cross-product buying view — supplier audit, formaldehyde-free selection and density by service condition — see our glass wool procurement checklist. Related Reading - Is Glass Wool Fireproof? A1 Non-Combustible Explained - Is Glass Wool Blanket Waterproof? - Non-Combustible Insulation Systems: A1 Fire Rating Explained - Rock Wool Blanket — for temperatures above the glass wool ceiling - Glass Wool Board — rigid form for walls, roofs, and equipment panels Related products: Glass Wool Blanket, Glass Wool Board Related applications: Building, Cement, Green Building & Retrofit, Petrochemical FAQ: Q: What is the standard density of glass wool blanket? A: Industrial glass wool blankets typically range from 10 kg/m³ to 80 kg/m³. Light-duty HVAC and acoustic applications use 10–24 kg/m³, standard pipe and vessel wrapping uses 24–48 kg/m³, and heavy-duty wall or equipment applications use 48–80 kg/m³. Higher density improves mechanical stability but adds weight and cost. Q: What temperature can glass wool blanket withstand? A: Standard glass wool blankets are rated for continuous service from about -50 °C to 350 °C, with high-temp variants reaching approximately 450 °C. Peak exposure should not exceed 500 °C. For service temperatures above 450 °C, rock wool or ceramic fiber is the safer choice. Q: Is glass wool blanket A1 fire rated? A: Yes. The inorganic glass fiber core is non-combustible and can achieve A1-s1,d0 under EN 13501-1 and Class A under ASTM E84. However, the complete product — including facings, coatings, and adhesives — must be tested as a whole. Some foil or polymer facings can downgrade the finished roll, so always request the classification report for the exact SKU. Q: How do I choose between glass wool and rock wool blanket? A: Choose glass wool when you need the lowest thermal conductivity at room temperature, light weight, easy handling, and acoustic absorption, and when service temperatures stay below 350–450 °C. Choose rock wool when you need higher temperature resistance (up to ~750 °C), greater rigidity, or better performance in vibration and moisture-prone industrial environments. Q: What should I check before buying glass wool blanket in bulk? A: Verify the third-party test report for thermal conductivity, density tolerance, fire class, water repellency, and shot content. Confirm ISO 9001 and CE (or equivalent) certification. Check that the facing matches your environment, ask for a sample roll to verify recovery after compression, and agree on batch testing, delivery lead time, warranty, and technical support in the purchase contract. Q: What sizes does a glass wool blanket come in? A: Sheet width is commonly 1200 mm, with narrower strips cut for pipe wrapping. Thickness typically ranges from 25 mm to 100 mm, and roll length depends on thickness, density and the compression ratio, so it varies by manufacturer. Specify width, length, thickness and density in the enquiry, and confirm the supplied roll length in writing. Q: How much does a glass wool blanket compress during transport? A: Vacuum-compressed rolls typically pack to about one-fifth to one-eighth of their unpacked volume. Light 10–16 kg/m³ rolls compress hardest, while heavy 48–80 kg/m³ blankets compress least. After unpacking, allow 24–48 hours of recovery in dry indoor storage, and measure recovered thickness on a sample roll before large installations. ### Ceramic Fiber Bulk: Grades, Uses & How to Apply (2026) URL: https://www.rosetexwool.net/news/ceramic-fiber-bulk-grades-uses-application/ 2026-08-24 | Author: Rosetexwool Editorial | Category: industry insight Summary: A practical guide to ceramic fiber bulk grades, high-temperature applications, and installation methods for furnaces, kilns, and industrial equipment. Quick answer: Ceramic fiber bulk is a loose, unformed high-temperature insulation made from aluminosilicate fibers. It is classified by temperature rating from 1,050 °C to 1,500 °C and is used to fill expansion joints, back-up furnace linings, and feed the production of blankets, modules, ropes, and textiles. Because it is binder-free, it keeps its thermal stability up to the maximum rated temperature of the fiber grade. Specifiers choose bulk fiber when they need a fill material that can be packed into irregular cavities, or when they want the raw material for vacuum-formed parts and custom shapes. Compared with blankets and modules, bulk fiber is lower cost per kilogram and easier to transport, but it requires on-site handling, compaction control, and dust management during installation. This guide covers the common grades, the blown-vs-spun process difference, where bulk fiber is used, and how to install it safely and effectively. Ceramic Fiber Bulk Grades and Temperature Ratings The most important selection parameter for ceramic fiber bulk is its classification temperature — the maximum temperature at which the fiber retains its structure in a short-term laboratory test. The continuous use temperature is typically 100–150 °C lower and is the number that governs real service life. Grade | Classification temp | Continuous use temp | Al₂O₃ | ZrO₂ | Fe₂O₃ | Typical use | Common / 1,050 °C | 1,050 °C | ≤ 1,000 °C | 44% | — | < 1.2% | Low-temperature plant, flues, duct backup lining | Standard / 1260 °C | 1,260 °C | ≤ 1,100 °C | 45–46% | — | < 1.0% | General furnaces, boilers, expansion joints | High-purity / 1260 °C | 1,260 °C | ≤ 1,100 °C | 47–49% | — | ≤ 0.2% | Processes sensitive to iron contamination | High-alumina | 1,350–1,400 °C | ≤ 1,200 °C | 52–55% | — | ≤ 0.2% | Glass tank furnaces, ceramic kilns, hot faces | Zirconia-alumina | 1,360 °C | ≤ 1,200 °C | 45–46% | 5–7% | ≤ 0.2% | High thermal-shock zones | Zirconia / 1430 °C | 1,430 °C | ≤ 1,350 °C | 39–40% | 15–17% | ≤ 0.2% | Severe thermal cycling, chemical exposure | Chrome-bearing | 1,500 °C | ≤ 1,350 °C | ≥ 42.5% | — | ≥ 2.6% (Cr₂O₃) | Extreme temperature, controlled-health environments | Thermal conductivity increases with temperature. A typical 1260 °C grade measures roughly 0.045–0.060 W/(m·K) at 200 °C and 0.15–0.20 W/(m·K) at 600 °C. Higher alumina and zirconia grades trade slightly higher conductivity at low temperatures for much better creep resistance and dimensional stability above 1,200 °C. Density, Shot Content and Thermal Conductivity: What the Numbers Mean Five numbers on a ceramic fiber bulk data sheet decide whether the material will perform in service. Reading them together prevents most field failures. Classification temperature vs continuous use temperature. Classification temperature is a short-term laboratory result; continuous use temperature is 100–150 °C lower and is the figure that governs service life. Specifying on the first number is the single most common ordering error. Shot content. Shot is the non-fibrous pellet that survives fiberizing, reported as the percentage retained on a stated sieve. It is the most under-specified number on a bulk order. Standard grades typically run up to about 20 % shot; high-purity and zirconia grades are usually held to roughly 15 % or less. High shot makes the fiber dustier to handle, packs to a less uniform density, and raises thermal conductivity because the pellets conduct heat far better than the fiber mat. If the material will be vacuum-formed or converted into blanket, specify a maximum shot content rather than just a grade name. Installed density. Loose ceramic fiber bulk is sold by weight but performs by volume. Installed density for direct fill is normally 80–160 kg/m³: the lower end for static cavity fill where insulation value per millimetre matters most, the upper end for joints and door seals exposed to gas velocity or vibration. Compressing beyond the design density improves erosion resistance but reduces thermal performance, so the target density belongs on the drawing instead of being left to the installer. Thermal conductivity at temperature. Conductivity has to be quoted at the mean temperature of service, not at ambient. A 1260 °C grade that measures about 0.045–0.060 W/(m·K) at 200 °C will read roughly 0.15–0.20 W/(m·K) at 600 °C. Comparing two suppliers on a single ambient figure is meaningless. Permanent linear shrinkage. Measured after a defined soak at temperature, shrinkage tells you how much the fill will settle in service, and therefore how much you need to over-fill on the first pass. For a wider view of how each temperature tier is defined across insulation wool families, see our high-temperature insulation wool temperature ratings guide. Blown Fiber vs Spun Fiber Ceramic fiber bulk is produced by either blowing or spinning molten aluminosilicate: Process | Fiber diameter | Length | Characteristics | Best for | Blown | 2–3 µm | Short, uniform | Fine, fluffy, low shot content, excellent fill | Vacuum forming, expansion joints, lightweight fill | Spun | 3–4.5 µm | Longer, tangled | Higher tensile strength, better handling | Textile feedstock, modules, sprayed linings | Blown fiber creates a softer, more uniform pack and is preferred where the material will be vacuum-formed into boards or shapes. Spun fiber is tougher and is the normal feedstock for blankets, ropes, and modules because the longer fibers hold together under mechanical stress. Ceramic Fiber Bulk vs Blanket and Module: Choosing the Right Form Ceramic fiber bulk, blanket, and module are the same base fiber in three delivery forms, and the choice is usually economic rather than thermal. Decision factor | Ceramic fiber bulk | Blanket | Module | Best for | Irregular cavities, joints, patching, conversion feedstock | Large flat or curved surfaces, wrapped pipe | Fast furnace wall linings | Binder | None | Small organic binder, burns out on first heat-up | Small organic binder, burns out on first heat-up | Density control | Installer-dependent | Factory-set, consistent | Factory pre-compressed | Labour | High — on-site packing and dust control | Medium — cut, pin, butt joints | Low — anchor and release | Cost per kg | Lowest | Higher | Highest | Cost per m² installed | Can be highest once labour is counted | Medium | Lowest on large walls | Buy ceramic fiber bulk when the cavity shape defeats a preformed product, when you are patching or topping up an existing lining, or when you convert fiber into your own shapes, boards, and papers. Buy blanket or module when you are lining a large, accessible surface and labour dominates the material saving. A practical rule of thumb: if the crew can reach the surface and the area exceeds a few square metres, a preformed product almost always installs cheaper; if the crew has to push material into a void it cannot see, ceramic fiber bulk is the only form that works. Because ceramic fiber bulk carries no binder, it keeps its full rated temperature from the first heat-up — the reason it is also the preferred feedstock for vacuum-formed shapes, where any binder is added deliberately under controlled conditions. The same logic explains where the other two forms come from and what the binder costs you: see how ceramic fiber bulk becomes blanket and board for the needling and vacuum-forming routes side by side. For the formed products themselves, our comparison of ceramic fiber blanket, board, paper and cloth shows which form suits which duty, and the ceramic fiber blanket range covers the standard needled options. Where Ceramic Fiber Bulk Is Used Metallurgy: furnaces, ladles, and seals In reheating furnaces, annealing lines, and heat-treatment equipment, bulk fiber fills expansion joints, seals around doors and lids, and provides backup insulation behind dense refractory. Its resilience compensates for thermal movement and keeps hot gases from bypassing the working lining. For ladle and tundish covers, high-alumina or zirconia grades reduce heat loss and lower shell temperatures. The thermal-shock resistance of zirconia grades is especially valuable where furnaces cycle frequently. Petrochemical: cracking furnaces and reformers Ethylene cracking furnaces and catalytic reformer walls often combine a dense castable hot face with a ceramic fiber backup layer. Bulk fiber is used to pack cavities, seal around burner blocks, and insulate around anchors where prefabricated modules do not fit. In these units, replacing some dense refractory with fiber can cut shell heat loss substantially. For petrochemical applications, see our petrochemical insulation page. Power generation: boilers and gas turbines Utility and industrial boilers use 1260 °C bulk fiber to fill expansion joints, seal penetrations, and insulate around headers and supports. Gas turbines use bulk fiber as a fill around combustor cases and transition ducts where a soft, conformable seal is needed between rigid metal parts. Glass, ceramics, and cement kilns High-alumina bulk fiber withstands the alkaline and abrasive environment inside glass tank furnaces and ceramic kiln roofs. It is used as a backup lining and to fill joints between dense refractory bricks. In cement and lime kilns, zirconia grades resist the combined effects of high temperature, thermal shock, and dust erosion. Other applications - Expansion joints in any high-temperature vessel that cycles thermally. - Vacuum-formed shapes such as cones, sleeves, and burner tiles. - High-temperature filtration media when processed into fiber papers or felts. - Fire protection behind cladding or around penetration seals. - Acoustic and vibration damping in marine and heavy transport compartments. How to Apply Ceramic Fiber Bulk Direct fill Direct filling is the simplest application method and is ideal for expansion joints, door seals, and backup insulation cavities. - Prepare the cavity. Remove debris, loose refractory, and oil. The surface should be dry. - Install anchors if needed. For furnace-wall backup layers, place anchors on the cold shell at the spacing specified by the design. - Fill in layers. Add fiber in 40–50 mm layers, distributing it evenly. Avoid dumping large clumps, which create density gradients. - Compress slightly. Over-fill by 10–15% and compress gently so the pack stays in contact with the walls after the first heat-up shrinkage. - Seal the surface. A thin layer of ceramic fiber coating or a covering blanket reduces surface erosion and dust release. Target installed density for direct fill is usually 80–160 kg/m³, depending on the duty. Higher density gives better erosion resistance but lower thermal insulation per millimeter of thickness. Field procedure for expansion joints. Joint width is typically 25–50 mm, set by the expected thermal movement of the lining. Where the joint is wide enough to need restraint, fit metal anchors on the cold side at 300–500 mm spacing so the anchor steel stays below its own temperature limit. Fill in layers no thicker than 50 mm, over-fill by 10–15 % and compress each layer lightly so the pack stays resilient rather than densified. Finish the surface flush to within ±5 mm, then seal with a ceramic fiber coating or a covering blanket so hot gas cannot channel along the joint. Processing into blankets, modules, and textiles Bulk fiber is the raw material for most formed ceramic fiber products: Ceramic fiber bulk is the raw material for most formed ceramic fiber products, and the conversion route is exactly why the blown-versus-spun decision matters at ordering stage. - Blanket. Bulk fiber is blended with a small share of organic carrier fiber — typically around 15 % — to give the web enough green strength to run through the line. The blend is opened and carded into a uniform web, then needle-punched at roughly 20–50 needles per cm² so the layers interlock without being crushed. The mat is dried, usually for 10–24 hours at 100–150 °C, then trimmed and rolled. See our ceramic fiber blanket line for formed products. - Modules. Blanket is cut or folded into blocks, pre-compressed by roughly 10–20 %, banded, and dried so it expands against the shell once installed and forms a joint-free lining. Folded modules are normally laid in a soldier course with the folds running parallel to the hot face; stacked and parquet layouts are used where the design calls for them. - Textiles. Spun fiber is blended with about 10–15 % reinforcement — continuous glass filament or heat-resistant alloy wire — plied into yarn, then braided or woven into rope, tape, and cloth at roughly 18–22 picks per centimetre. Large-diameter ropes are built over a metal core so they hold their shape under compression. Choosing between those finished forms — and setting the reinforcement to suit the duty — is covered in our ceramic fiber rope, tape, cloth and paper buying guide. - Vacuum-formed shapes and board. Blown fiber is slurried with a binder, vacuum-dewatered onto a screen of the required profile, dried, and machined. This is the route for cones, sleeves, burner tiles, and custom shapes, and the reason converters buy blown rather than spun fiber. - Paper and felt. Wet-laid from a short-fiber slurry and used for gaskets, parting layers, and high-temperature filtration media. Spray application For complex surfaces such as ductwork, flues, and incinerator walls, bulk fiber can be sprayed with an inorganic adhesive. Sprayed linings conform to irregular shapes and can be applied over existing refractory. The layer is built up in passes until the specified thickness is reached, then trimmed and coated. This method requires trained crews and dust-control equipment. Common Specification Mistakes with Ceramic Fiber Bulk Most bulk fiber problems trace back to one of six ordering errors, and all six are avoidable at enquiry stage. - Ordering to classification temperature. A 1,430 °C grade is normally rated for ≤ 1,350 °C continuous use. Write the continuous figure into the specification. - Leaving shot content open. Without a maximum, a low-cost quotation can arrive with a materially dustier, denser-packing fiber. Set the limit and the sieve size. - Specifying thickness instead of installed density. Loose fiber compacts. A thickness on the drawing with no density target will be installed anywhere from 80 to 200 kg/m³ depending on the crew, with a correspondingly wide spread in thermal performance. - Treating every grade within one class as equal. Two fibers both sold as "1260 °C" can differ in alumina content by several percent, and the purer one will hold its structure longer at the top of the range. Ask for the chemical analysis, not just the class. - Ignoring the service atmosphere. Reducing atmospheres, alkali vapour from glass and cement kilns, and fuel or oil impingement in fired heaters attack aluminosilicate fiber differently. Above roughly 1,200 °C in a contaminated atmosphere, step up to a high-alumina or zirconia grade. - Forgetting the health classification. Where local rules require low-biopersistence fiber for new installations, ordering a standard aluminosilicate grade creates a compliance problem at handover. State the biosoluble requirement in the enquiry, not after delivery. Safety and Handling Ceramic fiber bulk is an inhalation hazard in its loose form. Always follow these practices: - Wear PPE: dust mask or respirator, safety goggles, gloves, and long sleeves. - Ventilate the work area and use local extraction where possible. - Avoid dry sweeping. Use vacuum systems with HEPA filtration to collect spilled fiber. - Bag waste and dispose of it according to local regulations for industrial mineral fiber. - Check the product safety data sheet (SDS) for health classification and exposure limits in your jurisdiction. Some jurisdictions now encourage or require low-biopersistent (biosoluble) alkaline-earth-silicate fibers for new installations. Biosoluble fibers are designed to dissolve in lung fluid more quickly than traditional aluminosilicate fibers while retaining similar high-temperature performance. If you operate under EU REACH, UK COSHH, or similar frameworks, confirm whether biosoluble fiber is specified for your project. Specifying and Buying Checklist - Match grade to continuous service temperature, not classification temperature. A 1,430 °C grade is normally rated for ≤1,350 °C continuous use. - State the fiber process — blown or spun — if the bulk will be used as a feedstock for blankets or vacuum-formed parts. - Request a test report covering classification temperature, chemical analysis, shot content, and thermal conductivity at the operating temperature. - Confirm physical form: compressed bale, loose bag, or pre-blended for spraying. Bale density affects how much material you receive versus the installed volume. - Plan for dust control in the contract, including PPE, cleanup, and disposal. - Verify certifications: ISO 9001, CE marking where applicable, and third-party test reports from accredited labs such as SGS. Related Reading - Ceramic Fiber Blanket — formed, flexible high-temperature insulation - Ceramic Fiber Bulk — raw loose fiber for fill and formed shapes - Ceramic Fiber vs Rock Wool for Furnace Linings - Best Heat-Resistant Materials for Furnace (2026 Guide) - Petrochemical Insulation Applications - Ceramic Fiber Blanket vs Board vs Paper vs Cloth - High-Temperature Insulation Wool Temperature Ratings - Ceramic Fiber Raw Materials and Manufacturing Process For a dedicated manufacturer and supplier evaluation guide, see our refractory ceramic fiber (RCF) manufacturer selection. Related products: Ceramic Fiber Bulk Related applications: Green Building & Retrofit, Cryogenic Insulation, Building, Traffic & Fire Protection FAQ: Q: What is ceramic fiber bulk used for? A: Ceramic fiber bulk is used as a loose fill for expansion joints, furnace backup linings, door seals, and cavity insulation. It is also the raw material for manufacturing ceramic fiber blankets, modules, vacuum-formed shapes, ropes, and textiles. Its main advantage is that it is binder-free and therefore keeps its thermal stability up to the maximum rated fiber temperature. Q: What temperature can ceramic fiber bulk withstand? A: Commercial grades are classified from 1,050 °C to 1,500 °C. The continuous use temperature is typically 100–150 °C below the classification temperature: standard 1260 °C fiber is used up to about 1,100 °C, high-alumina grades up to about 1,200 °C, and zirconia grades up to about 1,350 °C. Q: What is the difference between blown and spun ceramic fiber? A: Blown fiber is finer (2–3 µm), shorter, and fluffier, making it ideal for vacuum forming and lightweight fill. Spun fiber is longer and tougher (3–4.5 µm), giving better tensile strength and handling for blankets, modules, and textiles. Q: How do you install ceramic fiber bulk? A: For direct fill, clean the cavity, install anchors if required, add fiber in 40–50 mm layers, distribute evenly, and compress about 10–15%. Seal the surface with a ceramic fiber coating or covering blanket. Bulk fiber can also be processed into formed products or sprayed with an inorganic adhesive for complex surfaces. Always wear dust PPE and follow local waste-disposal rules. Q: How do I choose the right ceramic fiber bulk grade? A: Select by continuous service temperature first: standard 1260 °C grades for general furnaces and boilers up to 1,100 °C; high-alumina grades for glass and ceramic kilns up to 1,200 °C; zirconia grades for severe thermal cycling or chemical exposure up to 1,350 °C. Then confirm the fiber process (blown or spun), shot content, and required certifications for your project. Q: What density should ceramic fiber bulk be packed to? A: For static cavity fill, 80–120 kg/m³ normally gives the best insulation per millimetre. For expansion joints, door seals, and any location exposed to gas velocity or vibration, pack to 130–160 kg/m³ for erosion resistance. Agree the target with the installer before work starts and put it on the drawing, because over-compaction is the most common reason a fill underperforms its data sheet. Q: Is ceramic fiber bulk the same as ceramic fiber blanket? A: No. Ceramic fiber bulk is loose, binder-free fiber sold by weight; blanket is bulk fiber that has been blended with a small amount of organic binder, carded into a web, needle-punched, and rolled. Ceramic fiber bulk is used to fill cavities and as conversion feedstock, while blanket is used to line accessible surfaces. Bulk fiber keeps its full temperature rating from the first heat-up, whereas blanket loses its organic binder during the first firing. Q: Can ceramic fiber bulk be reused after it has been heated? A: Only partially. Once fired, aluminosilicate fiber begins to devitrify and loses resilience, so recovered material compacts and insulates less effectively. Reuse is acceptable for low-duty backup fill or as a topping layer, but not in a joint or hot-face position where resilience is doing the sealing work. Fiber removed during a repair should be bagged and treated as waste rather than re-laid. ### Non-Combustible Insulation Systems: A1 Fire Rating Explained URL: https://www.rosetexwool.net/news/non-combustible-insulation-systems-a1-fire-rating/ 2026-08-23 | Author: Rosetexwool Editorial | Category: industry insight Summary: A1 is the highest Euroclass reaction-to-fire rating. This guide explains what A1 means under EN 13501-1, how it is tested, how it differs from A2, and which insulation families can reach it. A1 is the highest Euroclass for reaction to fire, not a synonym for fire resistance, low smoke, zero dripping, or safe end-use performance. For specifiers and procurement teams, the practical question is narrow but decisive: does a named, faced, dimensioned, fixed, and tested insulation product carry a class A1 fire rating, or is the label being borrowed from the material family? This guide explains what A1 means under EN 13501-1, how it is tested, how it differs from A2, how it maps across EN, BS, ASTM and China's national framework, which insulation families can reach it, where projects require it, and the exact evidence a buyer should request. A non-combustible insulation system starts with a documented product, not a material claim. What Does A1 Non-Combustible Mean? A1 identifies a defined construction product's contribution to fire growth under the EN 13501-1 classification route. A product with an A1 fire rating meets two complementary tests — EN ISO 1182 (non-combustibility) and EN ISO 1716 (gross heat of combustion) — and is therefore assumed not to contribute to fire growth or to the fully developed fire. The classification is precise about what it covers and what it does not: - It covers reaction to fire — the product's own decomposition under specified test conditions. - It does not establish fire-resistance duration (REI), smoke performance, flame-spread approval, acoustic or thermal performance, or acceptability in a particular assembly. For an EN 13501 A1 result, the classification criteria for the tested specimen are: - temperature rise ΔT ≤ 30 °C; - mass loss Δm ≤ 50 %; - no sustained flaming (tf = 0); - gross heat of combustion ≤ 2.0 MJ/kg. A1 is a tested result for a defined product. Treat it as the ceiling of the Euroclass reaction-to-fire scale, not as a blanket description of every inorganic insulation. For the full A1–F lattice with smoke and droplet subcategories, see our Euroclass fire classification guide. How A1 Is Tested and Classified An A1 classification is built from two tests; a third, the Single Burning Item (SBI) test, is explicitly not part of the A1 route. Test | Role in the A1 route | Result to verify | EN ISO 1182 | Non-combustibility | Specimen at 750 °C; ΔT ≤ 30 °C; Δm ≤ 50 %; no sustained flaming | EN ISO 1716 | Maximum heat-release potential | Gross heat of combustion ≤ 2.0 MJ/kg for A1 | EN 13823 (SBI) | Not used for A1 | Relevant to A2–D classification only | EN ISO 1182 exposes the specified specimen in a furnace stabilised at 750 °C and checks for sustained flaming, temperature rise and mass loss. EN ISO 1716 measures the maximum total heat the product would release if it burned completely. Both must be satisfied for A1. Crucially, EN ISO 1182 evaluates the specimen as prepared and presented — the foil-faced roll, bonded panel or installed assembly — not the bare fiber alone. The result applies only to the tested construction and condition; it does not evaluate an entire rainscreen assembly, cavity-barrier retention, or long-term in-situ performance. A product may shrink, embrittle or lose functionality while still satisfying the classification criteria. The most common error is assuming SBI proves A1. EN 13823 places two vertical specimens in a corner and measures heat release, smoke and flaming droplets; it is the route for A2, B, C and D. A compliant datasheet may show an SBI report for an A2-s1,d0 variant, but an A1 evidence stack should contain EN ISO 1182, EN ISO 1716, the classification report, and product or conformity documentation — not an SBI result as the basis for A1. The A1 Compliance and Documentation Chain Because A1 belongs to a defined product or system, the documentation must name the exact article. A robust A1 certification process starts with the classification report for the precise product, then — where the CPR (Construction Products Regulation) route applies — verifies the conformity chain. Specifiers should confirm: - exact product name, facing, thickness and density; - the EN 13501-1 classification report number, test laboratory and accreditation scope; - report date and validity conditions; - product-level or system-level scope; - the Declaration of Performance and Conformity (DoP/DoPC), the applicable assessment and verification system (AVCP/AVS), and CE information where relevant; - ETA number, EAD reference, TAB and transition status where an ETA/EAD route applies; - the installation and fixing method. A single private test report can support an A1 claim only when its product definition matches the marketed article. It does not by itself create an ETA, a DoP/DoPC, or CE conformity, and notified-body involvement is required only where the relevant system demands it — not for every A1 product. Where no harmonised standard covers the product, manufacturers may follow the EOTA route: a Technical Assessment Body issues an ETA on the basis of an EAD, and EAD references are published in the Official Journal of the European Union. Under the current CPR framework, the former Declaration of Performance becomes a Declaration of Performance and Conformity (DoPC); the exact conformity route depends on the product, date and adopted specification. CE marking demonstrates conformity with a declared-performance framework; it is not a substitute for checking the actual A1 report, system scope and installation conditions. A1 vs A2: Reaction to Fire, Not a Single "Non-Combustible" Category A1 and A2 both reflect limited combustibility, but the boundary is numeric and matters where a specification requires A1 rather than A2-s1,d0. Parameter | A1 | A2 | Gross heat of combustion | ≤ 2.0 MJ/kg | ≤ 3.0 MJ/kg | EN ISO 1182 / EN ISO 1716 | Required | Required | EN 13823 (SBI) | Not used | Required (FIGRA ≤ 120 W/s; THR600s ≤ 7.5 MJ; LFS < specimen edge) | A2 permits a higher total heat potential and a finite fire-development contribution measured by SBI, whereas A1 is based purely on non-combustibility and gross calorific value. That difference is why A1 cannot be downgraded to A2 simply because both classes use EN ISO 1182 and EN ISO 1716. Where a façade, cavity barrier or procurement spec calls specifically for A1, an A2-s1,d0 product — even with excellent smoke and droplet ratings — does not satisfy it. For a deeper A1 vs A2 vs B comparison, see A1 vs A2 vs B fire rating; the Euroclass fire classification guide covers the full A1–F ladder. A1 Across Standards: EN 13501, BS 476, ASTM E84 and China's National A1 All four frameworks address combustion behaviour, and several share a ~750 °C testing theme, but they use different product definitions, sampling rules and regulatory regimes. The correct position is prudent comparison, not automatic interchange. Scheme | Object and classification | Key basis | Defensible statement | EN 13501-1 A1 | Reaction to fire of a defined product | EN ISO 1182; EN ISO 1716 | Highest Euroclass reaction-to-fire result | BS 476 Part 4 | Non-combustibility of a material | 750 °C furnace | A relevant UK benchmark, not a label for all EN A1 products | ASTM E84 Class A | Comparative surface burning | 10-minute tunnel; flame-spread and smoke-developed index | Relevant to US exposed-surface specs | China national A1 | Chinese classification of a product | National non-combustibility and gross heat-of-combustion methods | A distinct Chinese result, separate documentation | A shared ~750 °C theme supports technical discussion, but EN 13501-1 A1, BS 476, ASTM E84 and China's national A1 remain separate classifications under separate regulatory regimes. Project conversion must follow the adopted local code and the competent design authority. Why BS 476 Class 0 Is Not an A1 Substitute In the UK context, Class 0 addresses specific wall and ceiling-lining provisions under BS 476 Parts 6 and 7, which cover fire propagation and surface spread of flame. BS 476 Part 4 assesses non-combustibility. Class 0 therefore combines a specific regulatory route and cannot be written as "Class 0 = A1." A product may be non-combustible under BS 476 Part 4 and still require separate evaluation for Class 0 or for EN 13501-1 A1, depending on the material, assembly, mounting and adopted route. Equally, an EN 13501-1 A1 classification does not by itself establish UK lining compliance or surface-flame-spread acceptability. Where a UK project requires Class 0, the responsible designer should confirm the actual BS 476 test report and regulatory route rather than inferring it from an A1 label. Four A1-Capable Insulation Families Compared Rock/mineral wool, glass wool, ceramic fiber and calcium silicate are all inorganic families that can be considered for A1 where the finished product carries appropriate classification evidence. Binders, facings, coatings and system components must be included in the tested product definition. Family | Inorganic basis | Why A1 is possible | Binder/facing caution | Typical density* | Typical service temp* | Typical λ* | Rock/mineral wool | Basalt/dolomite fiber | Low fuel content can meet 1182/1716 | Resin binders, oils, foil or coating can alter result | 23–200 kg/m³ | ~230 °C building; specials higher | 0.033–0.052 W/(m·K) | Glass wool | Vitreous silica fiber | Low-combustibility vitreous fiber | Organic binder, facing, vapour barrier, adhesive | 10–100+ kg/m³ | ≤ 230–250 °C building | 0.030–0.045 W/(m·K) | Ceramic fiber | Alumina-silica fiber | Refractory, very low fuel contribution | Organic carrier/lubricant or jacket must be tested | 50–300 kg/m³ | up to ~1600 °C | 0.08–0.18 W/(m·K) | Calcium silicate | Hydrated silicate matrix | Inorganic, often autoclaved | Organic reinforcement or coating can affect result | 240–400 kg/m³ | ~800 °C standard | 0.054–0.068 W/(m·K) | *Typical engineering ranges for orientation only; values vary with temperature, product form, density, facing and test method. Not a specification. These are general material properties, not verified Rosetex Wool values — confirm the exact product data before specification. Our rock wool insulation overview covers mineral wool forms and duties in detail. Rock and Mineral Wool: A1 Potential Depends on the Finished Product Mineral wool is produced from inorganic rock and formed into blankets, boards, pipe sections and lamellas. Its A1 potential depends on the finished product, including resin binders, processing oils, facings and installation adhesives — not only the base fiber. For building and HVAC forms, typical maximum operating temperatures are around 230 °C, while special products may be used at much higher temperatures. That spread makes it unacceptable to transfer a high-temperature product result onto a lightweight, binder-containing board without checking the tested article. High density or "rigid" construction does not independently establish A1, nor does high-temperature resistance. The correct question is whether the marketed product has been tested and classified in its final or representative form. Glass Wool, Ceramic Fiber and Calcium Silicate: Match the Material to the Duty Each family serves a different temperature and mechanical duty, and none transfers A1 automatically across forms. - Glass wool is common in building and HVAC applications where temperatures stay moderate; facings, vapour barriers and support systems must be included in the assessed product. Our glass wool fireproof guide addresses its reaction-to-fire behaviour specifically. - Ceramic fiber suits high-temperature industrial insulation — blankets, boards, modules and rope — with service temperatures that can reach ~1600 °C; some commercial forms contain temporary organic carriers that must be present in the tested product. - Calcium silicate is a rigid, often autoclaved silicate board or pipe section suited to structural backup and high-temperature industrial duty; see our calcium silicate insulation overview for forms and grades. Across all three, an A1 result must be obtained for the actual product and intended use. For high-temperature ceramic-fiber forms specifically, our ceramic fiber insulation overview covers the product range. Façades, ETICS and Cavity Barriers: System Evidence Comes First In façades, ETICS (external thermal insulation composite systems) and cavity-barrier design, fire performance depends on the complete assembly: insulation, render or cladding, substrate, adhesive, mechanical fixing, joints, fire barriers and cavity closers. An A1 insulation board is only one component. England's external-wall combustible-materials restriction — a national building-regulatory development, not an EU-wide rule — took effect on 1 December 2022 and, for relevant buildings, requires specified external-wall and attachment components to achieve A1 or A2-s1,d0 under BS EN 13501-1:2018. The applicable class, building height, attachment scope and system test remain project- and jurisdiction-specific. An A1 insulation result does not validate the whole system, and cavity barriers additionally need tested retention, compatibility and installation performance — A1 alone does not prove barrier integrity. Tunnels, BESS, Data Centres and Marine Applications These sectors require sector-specific fire-performance and system-test evidence; A1 is only one element. - Tunnels commonly specify fire-resistance-rated structures and linings selected for RWS/HCinc or ISO 834 curves and durations (PIARC recommends, for example, 60 minutes for cars and vans under ISO 834, or 120 minutes for lorries under RWS/HCinc). A1 alone is not the complete tunnel-fire solution. - BESS and data centres need system-level thermal-runaway and fire-propagation evidence. In the US, NFPA 855 is the model installation document, but adoption and enforcement are jurisdiction-specific; IEC 62933-5-2:2025 strengthens BESS fire-propagation measures. Design evidence should demonstrate thermal-runaway propagation for the actual module, rack, cabinet or container — for example through large-scale testing such as UL 9540A — together with a site-specific hazard analysis. A1 insulation supports that strategy at the material level but is one input, not the complete fire-safety case. - Marine and offshore projects must follow the IMO FTP Code and approved system documentation. A-60 and A-30 are division classifications with their own temperature-rise limits, not general insulation product classes. For the SOLAS/IMO framework and H-120 guidance, see our marine fire insulation materials and standards guide. Common A1 Misconceptions Separating classification from fire resistance, smoke, dripping and surface spread prevents the most frequent overclaims: - "A1 means fireproof." No — it is a reaction-to-fire result, not immunity to heat. - "A1 gives a fire-resistance duration." No — REI/耐火 ratings belong to the tested element or system. - "A1 guarantees low smoke and zero dripping." No — those are separate (A2-s1,d0) subcategories. - "A1 automatically approves surface flame spread." No — that is a different performance. - "Inorganic means automatically A1." No — binders, facings and coatings can change the result. - "A faced product inherits the unfaced result." No — foil, adhesive and coating change the tested article. - "A test report is automatic CE/ETA certification." No — the conformity chain must be in place. - "A1 in one country equals approval in another." No — regimes, sampling and assemblies differ. Compliance Checklist for Specifiers and Procurement Teams Use this checklist before requesting an "A1" price or sample. The most reliable way to prevent overclaims is to match the documentation to the installed product. - Product name/SKU and manufacturer entity - Thickness, density, facing, edges and dimensions - EN 13501-1 report number, laboratory and date - EN ISO 1182 and EN ISO 1716 results (ΔT, Δm, tf, PCS) - Product-level or system-level classification scope - DoP/DoPC, AVCP/AVS and CE status where applicable - ETA/EAD, TAB and transition status where applicable - Façade, ETICS, cavity, firestop or system test - Project jurisdiction and adopted code - Installation and fixing compatibility If the facing, thickness, adhesive, fixing or intended use differs from the classified article, request updated evidence before specification. How to Request A1 Evidence and Next Steps A useful A1 enquiry identifies the installed assembly, not only the material family. Share the substrate, insulation form, facing, thickness, fixing method, system assembly and project jurisdiction. Rosetex Wool product families include mineral-fiber, ceramic-fiber and calcium-silicate insulation; where an exact product has an EN 13501-1 A1 classification report and, where relevant, a valid conformity document for the declared intended use, that product may be specified as A1 non-combustible insulation. Material family and previous project experience do not transfer A1 to a different facing, thickness, adhesive, fixing or system configuration. If no current evidence exists for a specific article, the correct commercial wording is "available A1 options" or "contact us with your specification" — not a blanket A1 claim. Technical note: A1 relates to reaction to fire under EN 13501-1. Project compliance depends on the applicable jurisdiction, building or installation code, the complete system, and supporting documentation. This page is technical guidance, not a substitute for project-specific design, fire-engineering or regulatory review. Related Reading - Euroclass fire classification: A1–F, smoke and droplet ratings - Is glass wool fireproof? Reaction-to-fire explained - Marine fire insulation: materials and IMO standards - Rock wool insulation: forms, properties and applications See our traffic and fire-protection insulation applications for tunnels, transit, and A1 fire-rated passive protection. Related products: Calcium Silicate Insulation Board, Ceramic Fiber Cloth, Composite Silicate Plate Related applications: Cement, Green Building & Retrofit, Power Generation FAQ: Q: What does A1 mean for insulation? A: A1 means the defined construction product meets the EN 13501-1 reaction-to-fire route using EN ISO 1182 and EN ISO 1716. It indicates limited contribution to fire growth under the classification tests; it does not by itself establish fire resistance, smoke performance, or suitability for every assembly. Q: Does A1 require the SBI test? A: No. A1 follows EN ISO 1182 and EN ISO 1716. EN 13823/SBI is used for A2–D classification. An SBI report may appear for an A2-s1,d0 product, but it is not the basis for an A1 classification. Q: Is a Class 0 material the same as A1? A: No. Class 0 relates to specific UK wall and ceiling-lining provisions under BS 476 Parts 6 and 7. EN 13501-1 A1 follows a different classification route. A product may need separate reports for each regulatory system. Q: Can ASTM E84 Class A be called A1? A: Not automatically. ASTM E84 compares surface burning characteristics and reports flame-spread and smoke-developed index over a 10-minute test. It states that flame-spread index alone does not define a material as non-combustible. Project conversion requires the adopted local code and competent design authority. Q: Is foil-faced insulation still A1? A: Only if the faced product has an A1 classification that covers that exact facing, thickness and intended use. Foil, adhesives, coatings and laminates can change the tested article, so the documentation must match the installed product. Q: Does A1 insulation provide fire resistance? A: A1 addresses reaction to fire, not the fire-resistance duration of a wall, partition, duct or enclosure. Fire-resistance ratings such as REI or A-60 must be established for the complete tested element or system. Q: What should I ask a supplier for? A: Request the exact product name, thickness, density, facing, EN 13501-1 classification report, test laboratory, and — where CPR is relevant — DoP/DoPC and AVCP/AVS or ETA/EAD details. Also confirm the system test for façades, ETICS, cavities, tunnels, BESS or marine applications. ### Marine & Offshore Fire Insulation: Materials & IMO Standards Guide URL: https://www.rosetexwool.net/news/marine-offshore-fire-insulation-materials-standards-guide/ 2026-08-22 | Author: Rosewool Insulation Editor | Category: industry insight Summary: A practical guide to marine and offshore fire insulation: SOLAS/FTP Code fire ratings, A-60 vs H-60, and how to select rock wool, ceramic fiber, calcium silicate or glass wool for ships and platforms. Marine and offshore fire insulation must do two jobs at once: keep heat in (or out) and keep fire from spreading. Unlike land-based industrial insulation, shipboard systems operate in a salt-laden, high-vibration environment where every kilogram of material matters and evacuation routes are measured in minutes, not hours. That is why the marine-offshore application has its own rulebook: SOLAS, the IMO FTP Code, and the A-60 / H-60 fire-class system. This guide explains what those standards mean, how four common insulation materials compare, and how to choose the right system for each area of a vessel or offshore platform. For a first look at marine fire materials, see our companion article Marine Fire Insulation: Materials & Standards. What Makes Marine & Offshore Fire Insulation Different? Four factors separate marine work from a typical plant project: - Weight. Every extra kilogram of insulation reduces cargo or increases fuel burn. Lightweight materials with high temperature ratings are preferred where they can meet the fire class. - Corrosion. Salt air, condensation, and bilge water attack fixings and jackets. Materials that absorb water without drying can lose thermal performance and accelerate corrosion under insulation (CUI). - Vibration. Main engines, pumps, and propulsion machinery transmit constant vibration. Rigid boards can crack; fibrous blankets can settle if not properly supported. - Fire containment. A fire at sea cannot be fought with unlimited external support. Bulkheads, decks, and pipe penetration seals must hold their rating long enough for crew evacuation and boundary control. Because of these constraints, marine specifications almost always require IMO-certified, non-combustible materials rather than ordinary commercial-grade insulation. SOLAS & IMO FTP Code Fire Ratings Explained The International Convention for the Safety of Life at Sea (SOLAS) sets the structural fire-protection requirements for ships. The technical test procedures are given in the IMO FTP Code (Fire Test Procedures Code), currently consolidated in the 2010 edition. Key tests for insulation materials include: - Part 1 — Non-combustibility: sample exposed to 750 °C for 30 minutes; temperature rise, mass loss, and flaming behavior are recorded. - Part 2 — Smoke and toxicity: analysis of CO, HF, HCl, HCN, and other gases released during fire exposure. - Part 5 — Surface flammability: measurement of flame spread and heat release on exposed surfaces. Materials that pass are classed as A1 non-combustible under the same EN 13501-1 concept used onshore. A-Class vs H-Class Fire Divisions Fire class | Test fire curve | Insulation time | Temperature limits on unexposed side | Typical use | A-60 | Cellulosic (ISO 834) | 60 min | Average ≤ 140 °C; single point ≤ 180 °C | Engine-room boundaries, control stations, galleys | A-30 | Cellulosic | 30 min | Average ≤ 140 °C; single point ≤ 225 °C | Accommodation partitions, lower-risk divisions | A-15 | Cellulosic | 15 min | Same as A-30 | Non-critical divisions | A-0 | Cellulosic | 0 min | Integrity only, no insulation requirement | Cable/pipe penetrations with no temperature limit | H-60 | Hydrocarbon (ISO 834-3) | 60 min | Average ≤ 140 °C; single point ≤ 180 °C | Oil/gas processing areas, offshore platforms, LNG carriers | H-120 | Hydrocarbon | 120 min | Same as H-60 | High-risk offshore modules, FPSOs | The H-class hydrocarbon curve rises much faster than the cellulosic curve used for A-class. A material that passes A-60 is not automatically suitable for H-60; the higher heat flux and faster temperature ramp expose weaknesses in binders and facing systems. Material Comparison for Marine Fire Insulation Material | Max service temp | Fire class capability | Density | Marine strengths | Watch-outs | Rock wool blanket | ~650 °C | A1; A-60 / H-60 capable | 80–200 kg/m³ | Hydrophobic, salt-resistant, proven marine certs, good acoustic damping | Higher weight; needs robust fixing in vibration | Ceramic fiber blanket | up to 1430 °C | A1; H-60 / H-120 capable | 64–160 kg/m³ | Lightweight, extreme temperature, excellent thermal shock resistance | Fibrous dust requires PPE; fewer blanket marine type-approval listings | Calcium silicate board | 650–1050 °C | A1; A-60 / H-60 capable | 170–300 kg/m³ | Rigid, dimensionally stable, high compressive strength, long service life | Heavy; brittle; needs careful cutting and support | Glass wool blanket | ≤ 400 °C | A1; A-30 / A-60 | 10–120 kg/m³ | Low thermal conductivity, easy to cut, good acoustic absorption | High water absorption; must be protected by a vapor barrier at sea | For a closer look at calcium silicate, see our Calsil FAQ. Why not one material everywhere? No single insulation covers every marine zone. The winning specification usually layers or zones materials: - Rock wool blanket is the workhorse for A-60 and H-60 bulkheads, decks, and machinery casings where hydrophobicity and sound attenuation are valued. - Ceramic fiber blanket wins where exhaust manifolds, incinerators, or furnace casings exceed 650 °C and where weight savings justify the higher material cost. - Calcium silicate board is the structural choice for flat, walkable surfaces, pipe support shoes, and fire doors that must stay dimensionally stable for years. - Glass wool blanket is competitive in accommodation areas below 400 °C where acoustic performance matters, provided it is sealed against moisture. Where Each Material Fits on Ships and Offshore Platforms Engine Rooms and Machinery Spaces These are high-risk, H-class or A-60 zones with concentrated heat sources and heavy vibration. Rock wool blanket is widely used for bulkheads and casings because it is hydrophobic and resists salt corrosion. For surfaces above 650 °C — such as exhaust trunking or incinerator casings — ceramic fiber blanket is the safer thermal choice. Calcium silicate board can be used for flat structural panels and pipe support locations. Accommodation and Living Quarters Here the primary concerns are comfort, noise, and A-class fire division rather than extreme process temperature. Glass wool blanket provides good acoustic absorption and low conductivity at a light weight, but it must be installed behind an intact vapor barrier and metal facing to survive the humid marine atmosphere. Where the requirement is thermal rather than fire-driven — condensation control on chilled lines, cabin noise targets, cold-room and LNG service — the sizing logic is completely different, and our thermal insulation for ships and offshore platforms guide covers it in full. Piping Systems Hot process and steam piping on ships uses the same temperature-band logic as onshore, but with stricter fixing and sealing requirements: - ≤ 400 °C: glass wool or rock wool pipe sections, with sealed jacketing. - 400–650 °C: rock wool pipe sections or calcium silicate pipe covers. - > 650 °C: ceramic fiber wrap or high-temp calcium silicate shapes. Flanges, valves, and penetrations need removable insulation pads and approved fire seals. A common failure point is not the insulation itself but the joint seal, which must be rated to the same fire class as the adjacent bulkhead. Offshore Platforms and LNG Carriers Hydrocarbon fire risk pushes these projects toward H-60 and H-120 ratings. Rock wool blanket with a wire-mesh or metal-clad facing is frequently specified for module bulkheads and deckheads. For the most critical boundaries and high-temperature equipment, ceramic fiber or calcium silicate systems are layered behind steel cladding to achieve the required hydrocarbon rating. On the process side, offshore refinery insulation adds deck-load limits, module transport and amplified CUI pressure to those same fire ratings. Selection Framework for Marine Projects Use this sequence when writing or reviewing a specification: - Identify the fire class: A-60, A-30, H-60, or H-120. This is a hard constraint, not a recommendation. - Define the service temperature: continuous operating temperature plus upset/peak conditions. - Assess the environment: salt exposure, condensation, vibration level, and maintenance access. - Check approvals: verify the product carries a relevant marine type-approval or test report (IMO FTP Code, ASTM E84, EN 13501-1, or class society equivalents). - Balance weight and thickness: offshore topside modules may prefer thinner, higher-density systems; cargo vessels may prefer lighter blankets. - Plan the facing and sealing system: a hydrophobic core is not enough if water can enter at joints or jacket penetrations. Installation, Sealing and Maintenance Notes Even the right material fails if it is installed poorly. Common marine installation requirements include: - No gaps at frame edges: insulation must be packed tight against steel stiffeners so heat cannot bypass the fire barrier through a "cold bridge." - Mechanical fixings: adhesive alone is usually not acceptable in a fire-rated marine assembly. Use pins, clips, or mesh that match the fire class of the insulation. - Pipe and cable penetrations: use approved fire-stop collars, wraps, or mastic at every penetration. The penetration seal must match the division rating. - Metal jacketing: stainless-steel or aluminum cladding protects fibrous insulation from mechanical damage and salt spray, but overlaps must be sealed to keep water out. - Inspection interval: visually inspect fire-rated divisions at least annually; in high-vibration engine rooms, inspect every six months. Look for jacket damage, sagging blankets, detached pins, and corroded fasteners. For low-temperature or cryogenic offshore lines, our Cryogenic Pipe Insulation Guide covers the thickness and vapor-sealing logic. Related Reading - Marine Fire Insulation: Materials & Standards — first overview of the four material families and class-society certification. - What Is Calsil (Calcium Silicate) Insulation? — composition, forms, and specification checklist. - Cryogenic Pipe Insulation Guide — low-temperature offshore and LNG piping. Related products: Rockwool Insulation Blanket (Rock Wool Blanket), Ceramic Fiber Plus Blanket Related applications: Marine & Offshore, Nuclear Power FAQ: Q: What is the difference between A-60 and H-60 fire insulation? A: A-60 is tested against the standard cellulosic (building) fire curve and must keep the unexposed side within temperature limits for 60 minutes. H-60 is tested against the hydrocarbon fire curve, which rises much faster and is used for oil, gas, and offshore areas where liquid fuel fires are possible. A product that passes A-60 may not pass H-60. Q: Which insulation is best for marine engine rooms? A: Rock wool blanket is the most common choice for marine engine-room bulkheads and casings because it is non-combustible, hydrophobic, salt-resistant, and provides acoustic damping. Ceramic fiber blanket is preferred for surfaces above 650 °C, such as exhaust systems. Q: Why does marine insulation need IMO FTP Code approval? A: SOLAS requires that materials used in fire-rated shipboard divisions be tested under the IMO FTP Code. The code defines non-combustibility, smoke and toxicity limits, and surface-flammability tests. Without FTP Code evidence, a material generally cannot be used in A-class or H-class marine fire divisions. Q: Is rock wool suitable for offshore platforms? A: Yes. Rock wool blanket is widely used on offshore platforms for A-60 and H-60 bulkheads, deckheads, and machinery enclosures. Its natural water repellency and corrosion resistance make it well suited to salt-laden offshore air, provided it is installed with approved fixings and metal jacketing. Q: How often should marine fire insulation be inspected? A: Visually inspect fire-rated divisions at least annually. In high-vibration engine rooms, inspect every six months. Check for damaged jacketing, sagging blankets, detached pins, corroded fasteners, and failed penetration seals. ### Shengshi Jinding Attends 13th China Aluminum Industry Conference URL: https://www.rosetexwool.net/news/shengshi-jinding-13th-china-aluminum-industry-conference-2026/ 2026-08-21 | Author: Rosetexwool Editorial | Category: company news Summary: Shengshi Jinding attended the 13th China Aluminum Industry Conference in Shenyang to discuss low-carbon aluminum innovation and international cooperation. Shengshi Jinding Joins National Aluminum Industry Summit in Shenyang The 13th China Aluminum Industry Science & Technology Development Conference and Industrial Innovation & International Development Summit was held on August 20–22, 2026, in Shenyang, Liaoning Province. Zhengzhou Shengshi Jinding — the company behind the Rosetexwool brand — attended as an invited enterprise, joining academicians, research institutes, and upstream and downstream aluminum industry representatives to discuss technology innovation, low-carbon transformation, and international cooperation. Conference Focus: Technology, Low Carbon, and Digital Intelligence The conference theme was "Technology Leadership, Low-Carbon Digital Intelligence, Industrial Innovation and International Development." It focused on breakthroughs in aluminum industry science and technology, green and low-carbon development, digital and intelligent transformation, and international industrial collaboration. Specialists delivered keynote reports and joined round-table discussions on high-priority topics: - Energy saving and carbon reduction in electrolytic aluminum - Smart manufacturing and digital transformation - Industrial chain upgrading and international development - Green, low-carbon application practices On-Site Technical Exchange The Shengshi Jinding delegation listened to the latest industry reports, tracked policy direction and technology trends, and held face-to-face discussions with peers and technical experts. Conversations centered on high-temperature refractory and insulation materials for aluminum smelters, electrolytic cell supporting solutions, and green low-carbon practices. About Shengshi Jinding / Rosetexwool Shengshi Jinding has long specialized in high-temperature refractory and insulation materials for the aluminum, cement, petrochemical, power, and metallurgical industries. Under the Rosetexwool brand, the company manufactures and exports products including ceramic fiber insulation, rock wool, calcium silicate insulation, and nano-aerogel insulation systems to more than 50 countries. Looking Ahead Shengshi Jinding will use the conference as a platform to strengthen R&D investment, optimize products and services, and deepen collaboration with industry partners — supporting the high-quality, low-carbon, and intelligent development of the global aluminum industry. Related products: High Density Calcium Silicate Board Related applications: Iron & Steel FAQ: Q: What was the theme of the 13th China Aluminum Industry Conference? A: The theme was 'Technology Leadership, Low-Carbon Digital Intelligence, Industrial Innovation and International Development,' focusing on aluminum industry innovation, green development, digital transformation, and international cooperation. Q: What products does Shengshi Jinding supply to the aluminum industry? A: Shengshi Jinding provides high-temperature refractory and insulation materials, including ceramic fiber insulation, rock wool, calcium silicate insulation, and nano-aerogel insulation systems for aluminum smelters and other industrial applications. ### What Is Calsil (Calcium Silicate) Insulation? URL: https://www.rosetexwool.net/news/what-is-calsil-calcium-silicate-insulation/ 2026-08-21 | Author: Rosewool Insulation Editor | Category: industry insight Summary: Calsil is shorthand for calcium silicate insulation — rigid, asbestos-free board and pipe sections rated to 650 °C or 1 000–1 050 °C, with grades, forms and specification guidance. Calcium silicate insulation — shortened on site and on datasheets to calsil — is a rigid, asbestos-free insulation made by reacting lime and silica under high-pressure steam. It is supplied as board, pre-formed pipe section or custom block, and it is rated for continuous service at 650 °C, with high-temperature grades reaching 1 000–1 050 °C. If you have ever needed an insulation layer that can be walked on, bolted through, or used as a structural backup lining, calcium silicate insulation is the material that does it. Rock wool and ceramic fibre are flexible and have to be carried by something; calsil carries itself. It holds its shape, takes load without slumping, and gives a clean dimensionally stable surface inside furnace casings, boiler walls and kiln linings. That load-bearing behaviour scales with density, and the range is wide — a 220 kg/m³ board and a 1 000 kg/m³ board share a name but not a purpose. Where a specification depends on compressive strength rather than rigidity alone, our HD calcium silicate grades above 240 kg/m³ guide sets out the density bands, the strength curve, and where the temperature ceiling actually comes from. What Is Calcium Silicate Insulation? Calcium silicate insulation is a rigid inorganic thermal insulation composed principally of hydrous calcium silicate crystals, formed by the hydrothermal reaction of lime and siliceous material under steam pressure in an autoclave. The result is a lightweight but strong board or shape that combines low thermal conductivity with genuine structural capability — the property that separates it from every flexible wool on the market. Three things follow from that definition, and they explain most of the specification decisions around the material: It is a material, not a shape. Calcium silicate insulation is what the product is made of; board, pipe section and block are the forms it is delivered in. This matters when you read a specification, because "calcium silicate board" and "calcium silicate insulation" are often used to mean the same thing — and the naming across the industry is genuinely inconsistent. If that ambiguity has ever cost you time on a procurement query, our calsil versus cal-sil versus calcium silicate explainer settles it: the three names describe one material. It replaced asbestos millboard. That history is why "asbestos-free" appears on every modern datasheet. Modern calcium silicate insulation contains no asbestos and no respirable ceramic fibres, which is why it can be handled, cut and installed without the controls that legacy millboard or refractory ceramic fibre demand. It sits in a specific place on the temperature ladder. Standard grades run to 650 °C and high-temperature grades to 1 000–1 050 °C. Above that you move to ceramic fibre or polycrystalline mullite. For the full ladder across material families, see our top 10 high-temperature insulation materials guide. What Calsil Is Made Of and How It Is Produced The raw mix is simple: a lime source, a siliceous source — quartz sand, diatomaceous earth or fly ash depending on the producer — water, and a small fraction of reinforcing fibre. Cellulose and glass fibre are both common; the fibre is there for green strength and handling toughness, not for temperature performance, and it burns out in service. What turns that slurry into an insulation board is autoclaving. The mix is placed in a pressure vessel and cured in saturated steam, typically at around 180–200 °C under corresponding pressure, for a number of hours. Under those conditions the lime and silica react to form crystalline calcium silicate hydrate — most commonly the tobermorite phase for standard grades, and the xonotlite phase for high-temperature grades rated above about 1 000 °C. The crystal phase is not a detail for the materials engineer alone, because it sets the temperature ceiling. Tobermorite begins to dehydrate and lose strength as it passes roughly 650–700 °C, which is exactly where the standard grade's rating comes from. Xonotlite is stable well beyond that, which is why every 1 000 °C grade on the market is xonotlite-based. If a supplier quotes 1 000 °C on a tobermorite board, that is a question worth asking. After autoclaving the boards are dried, trimmed to size, and where specified faced with foil, tissue or glass cloth. Because the material is inorganic and contains no binder that has to cure in service, it does not smoke, outgas or change dimension on first heat-up — one of the reasons it is specified for oven and appliance panels as well as heavy industry. Key Properties at a Glance Property | Typical value | Continuous service temperature | 650 °C (standard); 1 000–1 050 °C (high-temperature grade) | Density | 170–240 kg/m³ (board); 200–300 kg/m³ (pipe section); 400–1 500 kg/m³ (high-density) | Thermal conductivity | 0.048–0.060 W/(m·K) at 50–100 °C; 0.10–0.12 W/(m·K) at 600 °C | Compressive strength | 0.5–1.0 MPa at 10 % deformation; higher with density | Fire rating | A1 non-combustible | Water uptake | Low capillary absorption; dimensionally stable when wet | Linear shrinkage | Low; holds geometry through thermal cycling | Chemical behaviour | Inert; rot, pest and vermin resistant | Three of these deserve comment, because they drive most of the value argument. Rigidity with low conductivity. Very few insulations do both. Calsil can be walked on, bolted through and used as a structural layer, which rock wool and ceramic fibre blankets cannot do — and it does it while holding conductivity in the same band as those materials. That combination is why it appears as the backup layer in composite linings. Dimensional stability through cycling. The boards are autoclaved at temperature and pressure, so they have already been through a form of the service condition before they reach site. Shrinkage is low and the material does not slump or settle, which keeps joints closed over years of thermal cycling instead of opening gaps in the first few months. The conductivity curve is not flat. Like every insulation, calsil conducts more as it gets hotter — roughly 0.048–0.060 W/(m·K) near ambient against 0.10–0.12 W/(m·K) at 600 °C. Specify against the value at your operating temperature, never the value at 25 °C. Our calcium silicate board density, thickness and conductivity spec guide carries the full curve and the thickness calculations built on it. Temperature Grades: 650 °C Standard vs 1 000–1 050 °C High-Temperature Two grades cover essentially the whole market, and choosing between them is the first decision in any specification. Standard grade — 650 °C continuous. This is the tobermorite-based board that does the bulk of industrial work: boiler casings, ductwork, oven panels, fire-rated doors, and the backup layer behind a hot-face refractory. It is the lower-cost option and it is entirely adequate wherever the substrate stays below 650 °C. High-temperature grade — 1 000–1 050 °C continuous. Xonotlite-based, formulated for kiln transition zones, heater linings and any position where the backup layer sees real heat. It carries a cost premium and slightly higher density, and it is the correct choice rather than the conservative one wherever the calculated interface temperature exceeds 650 °C — a standard board pushed past its ceiling does not fail gently, it dehydrates, loses strength and cracks. Above 1 050 °C. Calsil stops here. Ceramic fibre board takes over to roughly 1 260–1 430 °C, and polycrystalline mullite board above that. Where the choice is between calsil and ceramic fibre board specifically, our calcium silicate versus ceramic fibre board comparison works through the mechanical, thermal and cost trade-offs position by position. One practical caution: the grade rating is a continuous service figure, not a peak. Short excursions above the rating are survivable, sustained operation above it is not. State both your continuous and your peak temperature when you enquire. Density Grades: What Higher Density Buys You Density is the second specification axis, and it is where most of the price variation lives. Band | Typical density | What it is for | Standard | 170–240 kg/m³ (board) | Backup linings, duct and casing insulation, general industrial | Pipe section | 200–300 kg/m³ | Hot process pipework, steam lines | High-density | 400–800 kg/m³ | Load-bearing positions, kiln car decks, abrasion exposure | Ultra-high-density | 1 000–1 500 kg/m³ | Structural refractory shapes, ladle covers, high-wear zones | What higher density buys is strength, and what it costs is weight, thermal conductivity and money. Compressive strength rises steeply with density — a 220 kg/m³ board sits near 0.5 MPa at 10 % deformation while a 1 000 kg/m³ board is an order of magnitude stronger — but conductivity climbs too, because solid conduction through the skeleton has more material to travel through. The engineering answer is always the lowest density that meets the mechanical requirement, not the highest density available. Pipe sections run slightly denser than board for the same duty, because a curved segment has to hold its geometry against banding pressure and thermal movement without cracking at the seam. Specifiers looking for high density calcium silicate board are normally working in the 400–800 kg/m³ band, where the board carries a genuine mechanical load rather than only insulating — kiln car decks, ladle covers and positions exposed to abrasion or impact. Molded, Reinforced and Specialty Variants Beyond flat board and pipe section, three variants come up regularly in specifications. Molded calcium silicate. Rather than being cut from a flat board, molded shapes are formed to the finished geometry during manufacture — valve covers, turbine casings, irregular vessel heads, and the complex transitions where a flat board would need multiple pieces and multiple joints. The advantage is fewer joints, and joints are where heat escapes and where installation time goes. Reinforced calcium silicate. Glass fibre, or in some grades a chopped strand mat, is added to raise flexural strength and impact resistance. It is the standard answer where boards are handled repeatedly, where they are removed and refitted during maintenance, or where they span an unsupported gap. Faced and treated boards. Foil, tissue and glass cloth facings are applied for a range of reasons: to keep dust down during handling, to give a paintable or cleanable surface, to add a vapour barrier, or simply to make the board identifiable on site. Hydrophobic treatment is worth specifying wherever the insulation will be exposed to weather before cladding goes on — the material is dimensionally stable when wet, but wet insulation is not insulating. Calsil vs Rock Wool vs Ceramic Fiber | Calsil | Rock wool | Ceramic fiber | Max service temp | 650–1 050 °C | ~750 °C | up to 1 430 °C | Form | Rigid board/pipe | Flexible blanket/board | Flexible blanket/module | Compressive strength | High (load-bearing) | Low | Low | Handling dust | Minimal | Fibrous | Fibrous (PPE advised) | Best at | Structural backup, rigid surface | Irregular geometry, budget | Very high temperature | Cost | Mid | Low | Higher | Rule of thumb: choose calsil where you need a rigid, dimensionally stable surface or a backup layer that will not slump; choose rock wool blanket for irregular or curved surfaces on a budget; choose ceramic fiber where temperature exceeds 1 000 °C. In practice the three are frequently combined — ceramic fibre or rock wool on the hot face, calsil as the structural backup. Common Forms: Board, Pipe, Block and Custom - Board — the most common form, used as kiln and boiler backup lining, fire-rated wall and duct cores, and oven panels. Standard sizes and thicknesses cover most industrial duty; non-standard thicknesses are routine but move lead time. - Pipe sections — calcium silicate pipe sections are pre-curved segments supplied in matched halves for hot process pipes, standard in power and petrochemical plants. They are made to the pipe outside diameter and the insulation thickness together, so both numbers belong in the enquiry. For the wider picture on pipe insulation by material, see our industrial pipe insulation materials hub. - Block and custom shapes — for kiln car decks, ladle covers, and engineered furnace components where the geometry is fixed by the equipment rather than by the insulation. - Molded parts — see the variants section above; the right answer wherever a flat board would need more than two pieces to cover a shape. For a full material map by temperature tier, see best heat-resistant furnace materials (2026 guide). Typical Applications Calcium silicate insulation is widely specified in high-temperature industrial linings: cement kiln backup and transition zones (see cement kiln thermal protection), where the material's performance in that industry is covered in detail in our calcium silicate insulation cement industry guide; power-plant boiler casings and ducts (power generation applications), detailed in our power plant insulation guide; petrochemical heaters and reformers; fire-rated doors, panels and structural steel protection; and rock wool marine fire barriers. For the SOLAS/IMO standards and H-120 guidance, see marine fire insulation: materials and standards. It is frequently the rigid layer in a composite lining — ceramic fibre or rock wool on the hot face, calsil as the structural backup. That is the application the material was developed for and still the one where nothing else does the job as well. How to Specify and Source Calsil Work through six items and most of the specification writes itself: - Temperature class — 650 °C standard or 1 000–1 050 °C high-temperature grade. Give continuous and peak, not one number. - Density grade — higher density buys strength and costs conductivity, weight and money. Specify the lowest band that meets the mechanical requirement. - Dimensions and form — board thickness and sheet size, or pipe outside diameter plus insulation thickness for sections. - Facing and treatment — foil, tissue or glass cloth; hydrophobic treatment for weather exposure before cladding. - Standards and certification — confirm A1 non-combustible certification and any plant-specific or project-specific requirement. - Volume and logistics — annual quantity, whether custom shapes are needed, and delivery schedule. Custom molded parts are routine but they move both lead time and minimum order quantity. Ask for the conductivity value at your operating temperature rather than at ambient, and ask for compressive strength at a stated deformation rather than an unqualified number. Both are where datasheets are least comparable and where the difference between grades actually shows. For the full procurement walkthrough — supplier qualification, testing, and what a proper enquiry package looks like — see our calcium silicate insulation buyer's guide. Closing Calcium silicate insulation occupies one specific and irreplaceable position: the rigid, load-bearing, dimensionally stable insulation for service up to 1 050 °C. It is not the cheapest insulation per square metre and it is not the highest-temperature one, but where a lining has to support itself, hold geometry through years of cycling, and give a clean structural surface, it is the default answer. Send us your service temperature, density requirement, geometry and annual volume, and our engineers will return a thickness calculation, a grade recommendation and a quotation. Frequently asked What temperature can calcium silicate insulation withstand? Standard calsil is rated for continuous service at 650 °C. High-temperature grades are formulated for 1 000–1 050 °C. Above that, ceramic fibre or polycrystalline mullite boards are the better choice. Always specify both your continuous and your peak temperature — the rating is a continuous service figure, not a peak. Is calsil waterproof or water resistant? Calsil has low capillary water uptake and stays dimensionally stable if it gets wet — it does not soften or slump like some organic foams. It is water-resistant, not waterproof: prolonged immersion should be avoided, and the system should be allowed to dry out. In wet service, specify a hydrophobic grade or a waterproof cladding. Is calcium silicate insulation asbestos-free? Yes. Modern calcium silicate insulation is made from lime, silica and reinforcing fibre under autoclave curing. It contains no asbestos and is safe to handle without the precautions required for legacy asbestos millboard, which this material was developed to replace. Is "calsil" the same as calcium silicate? Yes. "Calsil" is simply trade shorthand for calcium silicate insulation board or pipe section. You will see the two terms used interchangeably across datasheets and specifications, along with the variant "cal-sil". All three describe the same material. Can calsil be used for pipe insulation? Yes. Calsil is available as pre-formed pipe sections and curved boards for hot process piping in power, petrochemical and steam systems — pairing low conductivity with the rigidity to stay in place without external support. Order by pipe outside diameter and insulation thickness together. What is the difference between standard and high-temperature calsil? The crystal phase. Standard grade is tobermorite-based and rated to 650 °C; high-temperature grade is xonotlite-based and rated to 1 000–1 050 °C. Xonotlite remains stable at temperatures where tobermorite dehydrates and loses strength, which is why the rating differs by roughly 400 °C. How does density affect calcium silicate insulation performance? Higher density raises compressive strength substantially — from around 0.5 MPa at 220 kg/m³ to an order of magnitude more at 1 000 kg/m³ — but it also raises thermal conductivity and weight, and it costs more. The right specification is the lowest density that meets the mechanical requirement, not the highest available. Can calcium silicate board be cut on site? Yes, with standard woodworking tools and appropriate dust extraction. It cuts cleanly and holds an edge, which is one reason it is used for fitted panels and oven components. Wear respiratory protection for the dust, and seal or face cut edges where the board will be exposed. Is calsil suitable for load-bearing applications? Yes — that is its defining advantage over flexible wools. Calsil can be walked on, bolted through, and used as a structural backup layer behind a hot-face refractory. Specify the density band against the actual load: standard board for self-supporting panels, high-density grades for kiln car decks and high-wear positions. What should I send to get an accurate quotation? Service temperature (continuous and peak), required density or compressive strength, form and dimensions — board thickness and sheet size, or pipe outside diameter plus insulation thickness — any facing or hydrophobic treatment, certification requirements, and annual volume. With those items a producer can return a firm specification and price rather than a range. Related products: Calcium Silicate Insulation Board Related applications: Cryogenic Insulation, Cement FAQ: Q: What temperature can calcium silicate insulation withstand? A: Standard calsil is rated for continuous service at 650 °C. High-temperature grades are formulated for 1 000–1 050 °C. Above that, ceramic fibre or polycrystalline mullite boards are the better choice. Always specify both your continuous and your peak temperature — the rating is a continuous service figure, not a peak. Q: Is calsil waterproof or water resistant? A: Calsil has low capillary water uptake and stays dimensionally stable if it gets wet — it does not soften or slump like some organic foams. It is water-resistant, not waterproof: prolonged immersion should be avoided, and the system should be allowed to dry out. In wet service, specify a hydrophobic grade or a waterproof cladding. Q: Is calcium silicate insulation asbestos-free? A: Yes. Modern calcium silicate insulation is made from lime, silica and reinforcing fibre under autoclave curing. It contains no asbestos and is safe to handle without the precautions required for legacy asbestos millboard, which this material was developed to replace. Q: Is "calsil" the same as calcium silicate? A: Yes. "Calsil" is simply trade shorthand for calcium silicate insulation board or pipe section. You will see the two terms used interchangeably across datasheets and specifications, along with the variant "cal-sil". All three describe the same material. Q: Can calsil be used for pipe insulation? A: Yes. Calsil is available as pre-formed pipe sections and curved boards for hot process piping in power, petrochemical and steam systems — pairing low conductivity with the rigidity to stay in place without external support. Order by pipe outside diameter and insulation thickness together. Q: What is the difference between standard and high-temperature calsil? A: The crystal phase. Standard grade is tobermorite-based and rated to 650 °C; high-temperature grade is xonotlite-based and rated to 1 000–1 050 °C. Xonotlite remains stable at temperatures where tobermorite dehydrates and loses strength, which is why the rating differs by roughly 400 °C. Q: How does density affect calcium silicate insulation performance? A: Higher density raises compressive strength substantially — from around 0.5 MPa at 220 kg/m³ to an order of magnitude more at 1 000 kg/m³ — but it also raises thermal conductivity and weight, and it costs more. The right specification is the lowest density that meets the mechanical requirement, not the highest available. Q: Can calcium silicate board be cut on site? A: Yes, with standard woodworking tools and appropriate dust extraction. It cuts cleanly and holds an edge, which is one reason it is used for fitted panels and oven components. Wear respiratory protection for the dust, and seal or face cut edges where the board will be exposed. Q: Is calsil suitable for load-bearing applications? A: Yes — that is its defining advantage over flexible wools. Calsil can be walked on, bolted through, and used as a structural backup layer behind a hot-face refractory. Specify the density band against the actual load: standard board for self-supporting panels, high-density grades for kiln car decks and high-wear positions. Q: What should I send to get an accurate quotation? A: Service temperature (continuous and peak), required density or compressive strength, form and dimensions — board thickness and sheet size, or pipe outside diameter plus insulation thickness — any facing or hydrophobic treatment, certification requirements, and annual volume. With those items a producer can return a firm specification and price rather than a range. ### Cement Kiln Thermal Protection: Insulation Engineering URL: https://www.rosetexwool.net/news/cement-kiln-thermal-protection-insulation-engineering/ 2026-08-20 | Author: Rosetexwool Editorial | Category: industry insight Summary: Engineering guide to cement kiln thermal protection: zone-by-zone insulation material selection, shell temperature reduction, and energy-saving case data for cement plants. Why Cement Kiln Thermal Protection Matters The rotary kiln is the single largest energy consumer in a cement plant. Heat loss from the kiln shell and preheater system typically accounts for 40–60% of total thermal energy input, and most of that loss passes straight through the lining and insulation. For a 5,000 t/d clinker line, every 10°C of unnecessary shell temperature can mean tens of thousands of dollars in extra fuel per year. Effective cement kiln thermal protection is therefore not a maintenance afterthought — it is a production and profitability decision. The right insulation system lowers shell temperature, reduces fuel consumption, protects the steel shell, and extends refractory life. The Cement Kiln Environment A cement kiln is not one uniform furnace. Along the length of the rotary kiln and its preheater tower, temperatures, chemistry, and mechanical loads change continuously. A sound insulation engineering strategy must match each zone to the material that performs best there. Temperature Zones Zone | Typical temperature | Key process role | Preheater top | 700–900°C | Raw meal preheating | Preheater lower / calciner | 900–1,150°C | Calcination | Transition zone | 1,200–1,400°C | Clinker formation begins | Burning zone | 1,450–1,500°C (gas to 2,000°C) | Sintering | Cooling zone | 200–1,300°C | Clinker cooling | Tertiary air duct | 900–1,100°C | Combustion air return | Kiln hood | 900–1,100°C | Burner / discharge area | Chemical and Mechanical Loads Beyond temperature, kiln linings face: - Alkali attack. K₂O and Na₂O vapors react with calcium-bearing materials above 650°C, forming compounds such as K₂CaSi₂O₇ that break down insulation structure. The reaction accelerates sharply near 1,100°C. - Sulfur and chloride corrosion. Fuel and raw-material variations introduce acidic gases that attack certain fiber materials. - Thermal cycling. The transition and cooling zones see rapid temperature swings. Materials must resist thermal shock and maintain low shrinkage. - Mechanical abrasion. Falling coating, moving load, and dust streams wear exposed hot-face surfaces. These factors make zone-specific material selection the foundation of cement kiln insulation engineering. Key Performance Requirements Any insulation product used in a cement kiln should be evaluated against the following criteria: Property | Requirement | Why it matters | Maximum service temperature | 600–1,500°C depending on zone | Prevents melting, shrinkage, and structural collapse | Thermal conductivity | 0.03–0.20 W/(m·K) depending on grade | Lower λ = lower heat loss and shell temperature | Compressive strength | 0.5–3.5 MPa | Resists handling, vibration, and thermal stress | Linear shrinkage | ≤3.5% at service temperature | Maintains lining integrity over years | Alkali resistance | ≤5% mass loss after 96 h alkali exposure | Survives the cement kiln vapor chemistry | Workability | Easy to cut, fit, and anchor | Controls installation cost and downtime | Material Selection by Kiln Zone The most efficient insulation systems do not rely on a single product. They layer materials so each layer handles the load it is best suited for. Preheater Top and Cooler Rear (≤900°C) At the cooler end of the process, rock wool board or calcium silicate board provides cost-effective thermal insulation. These zones are not exposed to heavy alkali load, so standard hydrophobic rock wool or medium-density calcium silicate performs well. Preheater Lower, Calciner, and Tertiary Air Duct (900–1,150°C) This is where alkali vapor concentration rises. Standard-grade ceramic fiber blanket or ceramic fiber modules are the conventional choice because they are lightweight and reduce shell temperature quickly. For severe alkali conditions, high-alumina or zirconia-containing ceramic fiber grades give better chemical resistance. Transition Zone (1,200–1,400°C) The transition zone demands both thermal insulation and mechanical toughness. High-alumina ceramic fiber blankets backed by a rigid backup layer are common. Where falling coating or mechanical impact is severe, a denser castable or brick hot-face may be required, with insulation behind it. Burning Zone (1,450–1,500°C) The burning zone is dominated by refractory wear, not lightweight insulation. The design is usually a high-grade magnesia-spinel or dolomite brick hot-face, followed by a thin but thermally efficient backup layer. Zirconia-reinforced ceramic fiber or high-density microporous boards can be used in selected cooler-gas pathways and hood areas adjacent to the burning zone. Cooling Zone and Kiln Hood (900–1,300°C) These areas see thermal shock as clinker temperature drops. A layered system — rigid hot-face or castable, plus calcium silicate insulation board and ceramic fiber backup — gives a good balance of strength, insulation, and shock resistance. Traditional Insulation Materials in Cement Kilns Calcium Silicate Insulation Board Calcium silicate board is widely used as a backup and mid-temperature insulation layer. Standard boards are rated to 650°C; high-density hard calcium silicate grades reach 1,000–1,050°C. Strengths: - Rigid, dimensionally stable - Good compressive strength (~0.55 MPa) - Non-combustible, A1 fire rating - Asbestos-free and low emission Limits: - Alkali resistance drops sharply above 650°C - Thermal conductivity increases at high temperature - Not suitable for the burning zone hot-face Best applications: preheater shells, cooler sections, tertiary air ducts, and as a rigid backup behind castables. Rock Wool Board Industrial rock wool board is an economical choice for lower-temperature areas (up to ~650°C continuous, depending on binder grade). It offers good thermal performance, fire safety, and sound absorption. Strengths: - Low cost per unit of thermal resistance - A1 non-combustible - Good acoustic damping - Chemically neutral, low chloride content Limits: - Maximum continuous service temperature lower than ceramic fiber - Higher density than some fiber alternatives - Needs protection from direct alkali vapor above rated temperature Best applications: preheater top, cooler rear, duct casing, and general building-services insulation around the kiln system. Ceramic Fiber Blanket and Modules ceramic fiber blanket and folded modules dominate the 900–1,300°C range. Grades range from standard (1,050–1,150°C) through high-alumina (1,260–1,300°C) to zirconia-containing (up to ~1,430°C). Strengths: - Low thermal conductivity, especially at high temperature - Light weight reduces steel-shell load - Excellent thermal shock resistance - Fast installation on curved shells Limits: - Standard grades are vulnerable to alkali vapor above 1,000°C - Long-term exposure above 1,200°C can cause embrittlement and dusting - Requires proper anchoring and compression Best applications: preheater lower sections, calciner, kiln hood, and as backup insulation behind refractory brick. Glass Wool Glass wool is useful only for the lowest-temperature parts of the cement plant — ductwork, electrical rooms, and personnel protection around equipment operating below ~250–300°C continuous. It is not suitable for kiln shell or preheater hot zones, despite excellent room-temperature thermal conductivity. Advanced Insulation for Modern Cement Plants Nano Microporous Insulation Boards Calcium-silicate-based nano microporous boards combine ultra-low thermal conductivity (roughly 40% lower than conventional materials in the 400–1,100°C range) with useful mechanical strength. Their pore structure is engineered into the nanometer scale, which suppresses gas-phase heat transfer. Engineering advantages: - Thermal conductivity as low as 0.018–0.025 W/(m·K) at mid-high temperature - High surface hardness and compressive strength - Stable to 1,100°C continuous; tolerates short thermal spikes above 2,000°C - Good alkali and corrosion resistance - Can be cut and installed without special encapsulation These boards are particularly effective in the calciner, preheater lower sections, and kiln hood, where they replace thicker conventional layers without increasing shell temperature. Zirconia-Reinforced Ceramic Fiber For the hottest zones that still need fiber flexibility, zirconia-stabilized ceramic fiber blankets offer service temperatures up to ~1,400–1,500°C. Their zirconia content improves both refractoriness and alkali resistance compared with standard alumino-silicate fiber. Engineering advantages: - Low thermal conductivity at 1,200°C (~0.05 W/(m·K)) - Excellent thermal shock resistance - Lightweight, reducing shell stress - Better alkali durability than standard ceramic fiber They are used in transition-zone backup, kiln hood, and specialized high-temperature duct linings. Modular Kiln Lining Systems Modern projects increasingly use modular lining systems: factory-engineered blocks that combine a hot-face refractory layer, an intermediate microporous or ceramic-fiber insulation layer, and an outer protective shell. The modules are lifted into place and anchored, cutting installation time and improving joint quality. For a major 5,000 t/d line upgrade in Central China, a modular lining system delivered: - Total lining weight reduced by 122 tonnes (18.7%) - Kiln shell temperature reduced by 90–130°C - Main drive motor current reduced by 250–300 A - Clinker power consumption reduced by 1.5 kWh/t - Coal consumption reduced by 3 kg/t clinker - Payback period: approximately 11 months Shell Temperature Reduction and Energy Savings The relationship between shell temperature and fuel cost is direct. Lower shell temperature means less heat radiated to atmosphere, which means less fuel is needed to maintain process temperature. Practical targets vary by zone, but typical improvements include: Zone | Typical uninsulated shell temp | Target with engineered lining | Estimated fuel saving | Calciner | 180–220°C | 120–150°C | 3–5% | Preheater lower | 160–200°C | 110–140°C | 2–4% | Kiln hood | 220–280°C | 140–180°C | 4–6% | Tertiary air duct | 150–190°C | 100–130°C | 2–3% | For a 5,000 t/d line, a 3% reduction in specific fuel consumption often translates to fuel savings well into six figures USD annually. The insulation upgrade pays for itself through lower fuel, lower electrical load on the kiln drive, and longer refractory campaigns. Multi-Layer Design Principle High-performance kiln insulation is almost always a multi-layer composite: - Hot-face working layer. Directly exposed to process temperature, abrasion, and chemical attack. Usually refractory brick or castable selected for the zone. - Intermediate insulation layer. Reduces heat flux toward the shell. Ceramic fiber modules, nano microporous boards, or high-temperature calcium silicate board depending on temperature and load. - Backup insulation layer. Further lowers shell temperature and smooths temperature gradients. Rock wool board or lower-density ceramic fiber. - Outer protection. Metal cladding, stainless-steel shields, or weatherproof coatings protect the insulation from rain, mechanical damage, and dust ingress. Each layer is selected so the material just inside its safe operating limit. Over-specifying one layer and under-specifying another is a common source of premature failure. Installation and Maintenance Notes Even the best materials fail if they are not installed correctly. Key points for cement kiln insulation projects: - Use modular, interlocking sections where possible to reduce cold joints and thermal bridges. - Stagger joints between layers. Never align the seams of the hot-face and backup layers. - Anchor carefully. Anchors must withstand thermal cycling without creating local hot spots. - Protect against infiltration. False air leaking through cracked casing bypasses insulation and raises shell temperature locally. - Plan inspection access. Build thermocouple ports and inspection hatches into the design so shell temperature can be monitored over time. - Schedule re-lining during planned stops. A rushed outage usually leads to poor joint quality and shorter campaign life. Composite Kiln Lining Wall Section: Hot-Face to Shell A high-performance cement kiln wall is built as a stack of layers, each chosen for the job it does best. Reading from the steel shell outward to the process gas: Layer | Typical material | Typical thickness | Primary role | Working (hot-face) layer | Refractory brick or castable, zone-specific | 150–250 mm | Withstand abrasion, chemistry, and peak temperature | Primary insulation | Ceramic fiber module or high-alumina blanket | 50–100 mm | Cut heat flux toward the shell | Ultra-low-λ backup | Nano microporous board | 20–50 mm | Suppress gas-phase conduction at high temperature | Rigid backup | Calcium silicate board | 40–80 mm | Dimensional stability and load support | Outer thermal break | Rock wool board | 30–60 mm | Lower shell temperature and smooth gradients | Protection | Steel shell + metal cladding | — | Mechanical and weather protection | Shell temperature is governed by the sum of each layer's thermal resistance, not by any single product. In practice, a thinner hot-face combined with a thinner but far more efficient microporous board often beats a thick conventional backup while saving kiln weight and drive power. The goal is to keep every layer operating just inside its safe limit — over-specifying one layer while under-specifying another is a common cause of premature failure. For a broader view of refractory selection across high-temperature equipment, see our furnace heat-resistant materials guide. Transition Zone Thermal Shock and Fatigue Management The transition zone swings between roughly 1,200°C and 1,400°C during start-up, load changes, and fuel swings. That cycling — not steady temperature — is what destroys linings. Key engineering controls: - Limit ramp rate. Fiber-lined shells should be heated and cooled at roughly 50–80°C per hour during commissioning and restart to avoid spalling and anchor stress. - Hold linear shrinkage ≤3.5% at service temperature. High-alumina and zirconia-stabilized ceramic fiber retains dimension far better under repeated cycling than standard fiber. - Control fiber grade. Above about 1,200°C long term, standard alumino-silicate fiber slowly crystallizes (mullite/cristobalite formation) and embrittles, eventually dusting. Where cycling is severe, specify high-purity or zirconia-stabilized fiber. - Manage anchor load. Differential expansion between the steel shell and the lining puts recurring load on anchors; use flexible anchoring and verify compression at each stop. Insulation Upgrade ROI: A Worked Calculation For a 5,000 t/d clinker line, the payback math is straightforward: - Baseline specific fuel consumption: about 110 kg coal-equivalent per tonne of clinker. - A 100°C shell-temperature reduction typically yields ~3% fuel saving → about 3.3 kg coal-equivalent per tonne. - Annual clinker output: 5,000 t/d × 330 operating days ≈ 1.65 million tonnes → fuel saved ≈ 5,445 tonnes coal-equivalent per year. - At an indicative USD 120 per tonne coal-equivalent, that is roughly USD 650,000 in annual fuel savings. - Added insulation (modules + microporous board + installation): on the order of USD 280,000 → simple payback of about 5–6 months, before counting extended refractory life and lower kiln-drive power. The same calculation scales down for smaller lines; the payback period lengthens but the fuel saving per tonne of clinker stays in the same band. Inspection and Re-Lining Cadence Good insulation is monitored, not forgotten: - Thermographic shell scan every 3–6 months. A zone running more than ~20°C above its documented baseline warrants investigation before it spreads. - Annual campaign review during the planned production stop — check joint integrity, anchor condition, and any local hot spot. - Re-line trigger: shell temperature creeping more than ~15% above the post-upgrade baseline, or exposed anchors, signals the working or backup layer has degraded. - Document a baseline shell-temperature map at commissioning so future scans have a reference. Additional Anonymized Project References - 2,500 t/d preheater tower retrofit (older line). Replacing thick castable preheater walls with ceramic fiber modules plus calcium silicate board cut preheater shell temperature by about 45°C, reduced fan power by roughly 4%, and shortened installation downtime by about 30% versus the original castable approach. - 4,000 t/d kiln hood (North Africa). Adding nano microporous board behind the existing brick lowered kiln-hood temperature by about 60°C and extended the refractory campaign by roughly two months. Figures are representative, anonymized outcomes from retrofit programs and are shared to illustrate typical magnitude rather than as a warranty. Related Reading - Cement plant insulation applications and material systems - Calcium silicate insulation board specifications - Ceramic fiber blanket for high-temperature kiln linings - Rock wool board for industrial and building insulation Related products: Calcium Silicate Insulation Board, Rockwool Insulation Blanket (Rock Wool Blanket), Calcium Silicate Pipe Related applications: Cement FAQ: Q: What is cement kiln thermal protection? A: Cement kiln thermal protection is the engineered combination of refractory and insulation layers that keeps process heat inside the kiln, protects the steel shell, and reduces fuel consumption. It covers the rotary kiln, preheater, calciner, cooler, and associated ducts. Q: Which insulation material is best for the cement kiln burning zone? A: The burning zone (1,450–1,500°C) is dominated by refractory wear, so a high-grade magnesia-spinel or dolomite brick hot-face is standard. Zirconia-reinforced ceramic fiber or microporous backup boards can be used in adjacent hood and duct areas. Q: How much energy can a cement kiln insulation upgrade save? A: Engineered kiln lining upgrades commonly reduce shell temperature by 90–130°C and specific fuel consumption by 2–5%. For a 5,000 t/d line, this can translate to six-figure annual fuel savings and payback periods under 12 months. Q: Can rock wool be used in a cement kiln? A: Yes, but only in lower-temperature zones such as the preheater top, cooler rear, and duct casing. Standard industrial rock wool is rated to roughly 650°C continuous, so it is not suitable for the calciner, transition zone, or burning zone. Q: Why is alkali resistance important for cement kiln insulation? A: Cement kiln flue gas contains K₂O and Na₂O vapors. Above 650°C these alkalis react with calcium-bearing insulation, destroying structure and increasing thermal conductivity. High-alumina or zirconia-containing ceramic fibers and nano microporous boards are preferred where alkali exposure is severe. Q: How often should cement kiln insulation be inspected or replaced? A: Plan a thermographic shell scan every 3–6 months and a full lining review during each annual planned stop. Re-line when a zone runs more than about 15% above its post-upgrade baseline temperature, or when anchors become exposed. Document a baseline shell-temperature map at commissioning so trends are visible. Q: What is a typical composite lining thickness for a cement kiln shell? A: A common build-up is a 150–250 mm refractory hot-face, 50–100 mm ceramic fiber module, 20–50 mm nano microporous board, 40–80 mm calcium silicate backup, and 30–60 mm rock wool outer layer. Exact thickness depends on the zone temperature and the fuel and alkali load; the aim is to keep every layer just inside its safe operating limit. ### Cryogenic Pipe Insulation: Material & Thickness Guide URL: https://www.rosetexwool.net/news/cryogenic-pipe-insulation-guide/ 2026-08-20 | Author: Rosetexwool Editorial | Category: industry insight Summary: A practical guide to cryogenic pipe insulation: compare rock wool, calcium silicate and aerogel by temperature, with a thickness-by-service-temperature chart and installation steps. What Is Cryogenic Pipe Insulation and Why It Matters Cryogenic pipe insulation protects piping that carries media below ambient temperature — from chilled process lines at -20 °C down to liquid nitrogen at -196 °C. Without proper insulation, the pipe surface drops below the dew point, water vapor condenses, and the resulting ice and corrosion attack the line from the outside in. For industrial facilities — LNG terminals, air-separation plants, refrigeration and cold-chain systems, and petrochemical operations — cryogenic insulation is what keeps product cold, energy bills low, and personnel safe. Selecting the right material and the correct thickness is the difference between a stable system and a failed one. Key Performance Requirements for Cryogenic Lines Low-temperature piping has different demands than hot-side insulation. A sound cryogenic insulation system must deliver: - Vapor tightness. The single biggest failure mode is moisture ingress. The insulation must include a continuous vapor barrier (typically aluminum foil or jacket) so water vapor never reaches the cold surface. - Fire safety. In chemical and LNG service, the material should be non-combustible — A1 class per EN 13501-1 — so it does not add fuel load. - Dimensional stability. At -196 °C the material must not shrink or crack. Quality products hold linear change ≤1.0% across the -196 °C to +70 °C range. - Mechanical strength. Pipe sections need enough compressive and tensile strength to resist thermal stress and handling loads. - Economy. Thickness is set by the economic-thickness method so lifecycle cost — not just first cost — is minimized. Best Materials for Cryogenic Pipe Insulation Rock Wool Pipe Sections Pre-formed rock wool pipe insulation (hydrophobic grade) is the workhorse for moderate cryogenic service. With water repellency ≥99% and a dense fiber structure, it performs reliably down to about -50 °C when combined with a vapor barrier and aluminum jacketing. It is A1 non-combustible, cost-effective, and easy to install on site. For the practical temperature ceiling of the fiber, see our rock wool temperature guide. Calcium Silicate Pipe Calcium silicate pipe is a rigid, high-strength product suited to mildly cold and ambient-to-elevated service. Its closed-cell structure resists water, and it holds shape under pressure — ideal for buried or mechanically stressed lines. Practical lower limit is around -20 °C; below that, rock wool or aerogel is preferred. Aerogel / Microporous (Nano Insulation) Aerogel and microporous blankets are the premium choice for deep cryogenic duty. At -196 °C their thermal conductivity is just 0.018–0.022 W/(m·K) — roughly one-third of traditional materials — so a 10–20 mm layer replaces 80–150 mm of conventional insulation. They stay flexible at liquid-nitrogen temperature and are A1 non-combustible. This makes them the standard for LNG (-162 °C) and liquid-nitrogen transfer lines. The nano aerogel insulation blanket and nano insulation board are the two forms supplied for this duty. Materials to Use With Caution Glass wool and ceramic fiber can appear in cryogenic specs but have limits: glass wool needs heavy hydrophobic treatment and is best above -20 °C; ceramic fiber is brittle below -50 °C and needs an aluminum-foil moisture wrap. For dedicated pipe runs, rock wool, calcium silicate, and aerogel cover the field more dependably. In practice most specifications settle on a layered approach: a thin aerogel core for thermal resistance where space is tight, backed by rock wool or calcium silicate for structure and economy. The industrial pipe insulation materials guide compares the full range of pipe insulation types. Material | Service range | λ at temp (W/(m·K)) | Typical pipe thickness | Notes | Rock wool pipe (hydrophobic) | -50 °C to +250 °C | 0.035–0.045 | 60–150 mm | A1, economical, needs vapor barrier | Calcium silicate pipe | -20 °C to +650 °C | 0.040–0.047 | 20–50 mm | Rigid, high strength, buried service | Aerogel / microporous | -196 °C to +300 °C | 0.018–0.022 | 3–20 mm | Ultra-thin, deep cryogenic, premium | The Full Cryogenic Insulation Material Family Cryogenic insulation is not a single material — it is a family spanning closed-cell and fibrous options, each matched to a temperature band and a structural role. Beyond the rock wool, calcium silicate and aerogel covered above, three further material families carry deep cryogenic insulation duty: Foam Glass / Cellular Glass Foam glass (also called cellular glass) is a closed-cell, zero-capillary material made by sintering crushed glass. It is A1 non-combustible, dimensionally stable and completely impermeable to water vapor, which makes it the default for LNG tank bases, buried cryogenic lines and any cryogenic insulation where a vapor-barrier failure cannot be tolerated. Its closed cells stay dry for decades and take compressive loads that would crush fibrous insulation; the trade-off is brittleness and higher weight, so it is usually paired with a flexible sealant layer at expansion joints. PIR / PUR Polyurethane Foam Rigid polyurethane (PUR) and polyisocyanurate (PIR) foams cover the low-temperature band from roughly -196 °C up to ambient, where their very low thermal conductivity (0.020–0.025 W/(m·K)) keeps the layer thin. They are lightweight and quick to apply in sprayed or pre-formed sections. Their key limitation is combustibility: PUR/PIR is not A1, so in LNG and chemical service it is either restricted to the cold end behind a non-combustible outer layer, or replaced by foam glass and aerogel in fire-critical zones. Perlite Expanded perlite is a loose-fill granular insulation poured into the annular space of double-wall LNG storage tanks and cold boxes. It is low-cost, non-combustible and fills irregular voids completely, but it performs only as a dry fill and must be kept under slight positive pressure or an inert purge to exclude moisture. Full Cryogenic Insulation Material Family Comparison Material family | Service range | λ at temp (W/(m·K)) | Cell type | Typical role in cryogenic insulation | Rock wool (hydrophobic) | -50 °C to +250 °C | 0.035–0.045 | Fibrous (open) | Moderate cold; needs vapor barrier | Calcium silicate | -20 °C to +650 °C | 0.040–0.047 | Closed-cell | Buried / mechanically loaded cold lines | Aerogel / microporous | -196 °C to +300 °C | 0.018–0.022 | Nanoporous | Deep cryogenic, ultra-thin | Foam glass / cellular glass | -268 °C to +430 °C | 0.038–0.050 | Closed-cell | LNG tank bases, buried, vapor-tight | PIR / PUR foam | -196 °C to +100 °C | 0.020–0.025 | Closed-cell | Cold end where thinness matters | Perlite (loose fill) | -268 °C to +650 °C | 0.040–0.060 | Granular | Annular fill in double-wall tanks | For a site-wide selection across every material family on the same duties, our cryogenic insulation applications guide walks through LNG, air separation and refrigeration duty unit by unit. Cryogenic Pipe Insulation Thickness by Temperature Thickness is driven by service temperature, pipe diameter, and the need to keep the outer surface above the dew point. The same diameter rule applies on the hot side: see pipe insulation types by diameter and layer count for where a single layer stops being the right answer. The chart below gives practical starting points for common materials. Service temperature | Recommended material | Recommended thickness | -20 °C to -50 °C | Rock wool pipe (hydrophobic) | 60–80 mm | -50 °C to -120 °C | Rock wool pipe or aerogel | 80–120 mm (rock wool) / 5–10 mm (aerogel) | -120 °C to -162 °C (LNG) | Aerogel / microporous | 8–15 mm | -162 °C to -196 °C (N₂, H₂) | Aerogel / microporous | 10–20 mm | -20 °C (mild, buried) | Calcium silicate pipe | 20–40 mm | Rule of thumb: every 10 °C deeper into cryogenic territory, conventional materials need substantially more thickness, while aerogel stays thin. For DN50 lines, aerogel economic thickness is often 6–12 mm versus 80–120 mm for rock wool. Pipe diameter matters as much as temperature. A small-bore line (DN25–DN50) needs proportionally more insulation per metre of pipe because its surface-area-to-volume ratio is high; a large line (DN200+) needs less depth for the same heat-loss limit. As a practical check, always run the diameter through the economic-thickness calculation in the next section rather than taking the table value as final. For the exact aerogel thickness selection method, our pyrogel-type insulation thickness guide works the numbers for both hot and cryogenic service. How to Install Cryogenic Pipe Insulation A correct installation is as important as material choice. Follow these steps: - Surface preparation. Remove rust, oil, and moisture from the pipe; reach Sa2.5 cleaning and 40–75 µm roughness. - Apply pipe sections. Fit rock wool or calcium silicate halves snugly; for aerogel, wrap the blanket tightly with 50 mm longitudinal and 100 mm circumferential overlap. - Seal joints. Use high-temperature adhesive plus butyl tape for a double seal; stagger seams between layers to avoid thermal bridges. - Install vapor barrier. Wrap a continuous aluminum-foil vapor barrier with ≥50 mm overlap and seal all penetrations. - Outer jacketing. Fix metal cladding to shed weather and mechanical impact. - Inspect. Verify no gaps, no cold bridging, and that the outer surface stays above the dew point. Work only when ambient temperature is ≥5 °C, relative humidity ≤85%, and wind ≤5 m/s; otherwise erect a sheltered enclosure. Pay special attention at valve and support points — these are where gaps and vapor leaks most often start, so add extra adhesive and a full barrier wrap before closing the jacket. Thickness Calculation Methods Two methods govern most specifications: - Economic thickness. Balances insulation first cost against lifetime energy savings. The result is then checked against anti-condensation requirements. - Anti-condensation thickness. Ensures the outer surface temperature stays at or above the dew point — critical in humid coastal or tropical sites. When the economically derived thickness would allow heat loss above the allowable limit, the maximum-allowable-heat-loss thickness governs. For layered systems above 80 mm total, install in multiple layers to prevent cracking. Worked example. A DN100 line (outer diameter ≈ 0.11 m) carrying LNG at -162 °C, ambient 25 °C, target outer-surface temperature 5 °C (above a 3 °C local dew point). Using rock wool with λ ≈ 0.040 W/(m·K), the cylindrical resistance formula gives a required thickness near 90–110 mm plus a full vapor barrier. The same line with aerogel (λ ≈ 0.020) needs only about 10–15 mm — the same resistance in roughly one-ninth the depth. The aerogel insulation thickness and cost guide shows how the thinner layer pays back over the project life. Design Considerations for LNG Terminals and Air-Separation Plants Large cryogenic facilities have system-level issues a single pipe run does not: - Thermal contraction. Lines shrink as they cool. Design fixed and sliding supports that absorb movement; never clamp insulation so tightly that contraction cracks the jacket. - Fire and safety zoning. LNG and air-separation plants sit inside strict hazard zones. Specify A1 non-combustible insulation throughout and coordinate jacket material with the plant fire strategy. - Access for inspection. Build in inspection ports and removable jacket sections at welds and valves so corrosion under insulation can be checked without stripping the whole line. - Load and space limits. On offshore and skid-mounted units, weight and footprint are constrained — this is where thin aerogel layers earn their cost by cutting both mass and volume. For petrochemical and refining duty, the same principles apply with added chemical-exposure limits; our rock wool petrochemical refining insulation guide covers material selection in those environments. The same scenario-by-scenario logic is set out in our cryogenic insulation applications guide, which treats cold storage, cold chain and LNG storage as three separate specification problems. Common Failure Modes and How to Prevent Them Most cryogenic insulation failures trace to a short list of causes: - Vapor-barrier breach. The single most common fault. A torn foil or unsealed penetration lets vapor in, which freezes and splits the jacket. Prevent with continuous overlap, sealed penetrations, and a pre-install leak check. - Cold bridging. Gaps at supports or uninsulated valve bodies create local cold spots that sweat and corrode. Bridge-free supports and full valve covers remove the path. - Wrong material at temperature. Using rock wool below -50 °C or calcium silicate below -20 °C leads to cracking and loss of effectiveness. Stay inside each material's service range from the table above. - Compaction. Heavy jacketing or foot traffic compresses fibrous layers, raising conductivity. Use rigid calcium silicate or a protected aerogel core where loads are high. Inspection and Maintenance A simple schedule keeps a cryogenic insulation system healthy: - Visual check at every turnaround — look for jacket damage, staining, or frost bleed that signals a barrier leak. - Surface-temperature survey with an infrared camera on a cold day; a surface below the dew point indicates failed insulation or bridging. - Barrier integrity test on lines in corrosion-under-insulation-risk zones every 3–5 years, using the inspection ports built into the design. Catch a breach early and a local re-wrap fixes it; ignore it and the whole section can be lost to corrosion under insulation. Related Reading - Cryogenic insulation applications across LNG, air separation and refrigeration - Rock wool pipe insulation product specifications - Calcium silicate pipe for industrial and buried lines - Nano aerogel insulation blanket for deep cryogenic duty - Rock wool for marine & offshore engineering - Industrial pipe insulation materials — full type comparison - Aerogel insulation thickness and cost guide Related products: Calcium Silicate Pipe, Rockwool Pipe Insulation for Steam Pipes Related applications: Environmental & Dust Removal, Building, Green Building & Retrofit FAQ: Q: What temperature range does cryogenic pipe insulation cover? A: Industry practice treats **-196 °C to -20 °C** as the cryogenic range. LNG runs at -162 °C and liquid nitrogen at -196 °C, while chilled process and refrigeration lines sit at the warm end near -20 °C. Q: Which insulation is best for LNG and liquid nitrogen pipes? A: **Aerogel or microporous (nano) insulation** is the standard for deep cryogenic duty — it stays flexible and efficient at -196 °C. [Rock wool pipe insulation](/products/rock-wool-pipe/) is suitable only down to about -50 °C and needs a full vapor barrier. Q: How thick should rock wool pipe insulation be at -40 °C? A: Plan for **80–120 mm** of hydrophobic rock wool pipe sections with a continuous aluminum-foil vapor barrier and metal jacketing. Below -50 °C, switch to aerogel. Q: Do cryogenic pipes need a vapor barrier? A: **Yes — mandatory.** Without a continuous vapor barrier, water vapor condenses on the cold surface, forms ice, and destroys the insulation from within. Aluminum foil plus sealed jacketing is the typical solution. Q: Can calcium silicate pipe be used for cryogenic service? A: Down to about **-20 °C**, yes — its rigid, closed structure suits buried and mechanically stressed lines. For colder service, use [rock wool](/products/rock-wool-pipe/) or aerogel. Q: How thick should cryogenic pipe insulation be? A: It depends on the service temperature: at −20 to −50 °C hydrophobic rock wool pipe runs 60–80 mm; at −50 to −120 °C use 80–120 mm of rock wool or 5–10 mm of aerogel; LNG (−162 °C) typically takes 8–15 mm of aerogel; and liquid nitrogen (−196 °C) 10–20 mm. For DN50 lines, aerogel economic thickness is often 6–12 mm versus 80–120 mm for rock wool. Q: What is cryogenic pipe insulation made of? A: Three materials dominate: hydrophobic rock wool pipe sections (good to about −50 °C with a vapor barrier), rigid calcium silicate pipe (to about −20 °C, for buried or stressed lines), and aerogel or microporous blankets (the standard for LNG and liquid nitrogen at −162 to −196 °C). All must be A1 non-combustible and dimensionally stable at low temperature. Q: What is the difference between economic thickness and anti-condensation thickness? A: Economic thickness minimizes lifecycle cost by balancing first cost against energy savings; anti-condensation thickness ensures the outer surface stays at or above the dew point so no moisture forms. Most specifications take the larger of the two as the governing value. Q: How often should cryogenic pipe insulation be inspected? A: Perform a visual and infrared check at every plant turnaround, and run a barrier-integrity test on corrosion-under-insulation-risk lines every 3–5 years using built-in inspection ports. Early detection lets a local re-wrap fix a breach before the whole section is lost. Q: What is foam glass (cellular glass) and when is it used in cryogenic insulation? A: Foam glass, also called cellular glass, is a closed-cell insulation made by sintering crushed glass. It is A1 non-combustible, completely impermeable to water vapor and dimensionally stable, which makes it the default for LNG tank bases, buried cryogenic lines and any cryogenic insulation where a vapor-barrier failure cannot be tolerated. It is heavier and more brittle than fibrous insulation, so it is usually paired with a flexible sealant at expansion joints. Q: Is perlite used in cryogenic insulation? A: Yes. Expanded perlite is a loose-fill granular insulation poured into the annular space of double-wall LNG storage tanks and cold boxes. It is low-cost, non-combustible and fills irregular voids completely, but it works only as a dry fill and must be kept under slight positive pressure or an inert purge to exclude moisture. ### Power Plant Insulation: Materials & Thickness by System URL: https://www.rosetexwool.net/news/power-plant-insulation-materials-thickness/ 2026-08-19 | Author: Rosetexwool Editorial | Category: industry insight Summary: How to specify power plant insulation by system — boiler, steam piping, turbine and HRSG — with recommended material and thickness based on operating temperature. Why Power Plant Insulation Matters In a thermal or combined cycle power plant, an estimated 5–10% of thermal energy escapes through the surfaces of boilers, pipes, and equipment. Good insulation is not a finishing touch — it is a core part of the plant's heat balance, safety envelope, and operating cost. Three things drive specification: - Fuel efficiency — every watt lost through a bare surface is fuel burned for nothing. - Personnel safety — codes typically limit exposed surfaces to roughly 50–60°C (or about 25°C above ambient for turbine and boiler casing) to prevent burns. - Equipment life — stable surface temperatures reduce thermal cycling, corrosion under insulation, and fatigue on rotating equipment. For a full map of where these materials fit across the plant, see our power generation insulation applications overview. How Insulation Thickness Is Determined Thickness is rarely a guess. Most plants size it with the economic thickness method: the point where further added insulation costs more than the energy it saves over the asset's life. Two constraints usually cap the result: - Maximum allowable heat loss — common design limits fall around 110–130 W/m² for hot piping. - Surface temperature limit — typically ≤ 50–60°C on accessible surfaces. Higher operating temperature, larger diameter, and a lower thermal conductivity all push the economic thickness upward. The tables below translate that into practical ranges for each system. Insulation by Power Plant System Boiler and Furnace Linings The furnace enclosure runs hottest — flame and radiant zones reach 800–1100°C, with flue gas at 400–600°C across the economizer, superheater, and reheater. - Radiant walls and arches (above 800°C): ceramic fiber blanket at 128 kg/m³, typically 50–100 mm, valued for very low heat capacity and excellent thermal-shock resistance during frequent start-stop cycles. - Economizer and superheater sections (400–800°C): a composite of ceramic fiber plus calcium silicate board (total 150–200 mm) balances low conductivity against the mechanical strength needed for casing and support. Steam and Feedwater Piping - Main and hot-reheat steam (350–540°C): ceramic fiber + calcium silicate composite, 150–200 mm, to hold surface temperature and heat loss within code. - Feedwater and low-temperature steam (150–250°C): rock wool blanket or glass wool, 80–120 mm — rock wool's higher density suits outdoor and mechanically exposed runs. - Hydrogen-cooled generator piping (~ -40°C): high-density rock wool or ceramic fiber, 100–120 mm, with a non-combustible outer jacket for the explosive-atmosphere requirement. Turbines and Rotating Equipment Turbines add a vibration constraint. Specifiers favor flexible ceramic fiber or rock wool (80–100 mm) with stainless pinning at ≤ 250 mm spacing, so the lining stays put through decades of cyclic loading. Turbine casing surfaces are typically held within ~25°C of ambient. Combined Cycle and HRSG In a combined cycle plant, the heat recovery steam generator (HRSG) sees gas-turbine exhaust at 400–600°C. The casing, ducts, and stack are insulated with ceramic fiber blanket or a ceramic-fiber/calcium-silicate composite, while the HRSG steam piping follows the same 150–200 mm composite rule as the main steam line. Gas-turbine exhaust ducting often uses ceramic fiber modules for fast cyclic response. Recommended Thickness by Temperature Range Operating temperature | Recommended material | Density (kg/m³) | Conductivity (W/m·K) | Typical thickness | Common systems | > 800°C | Ceramic fiber blanket | 128 | 0.045–0.060 @200°C; 0.152–0.200 @600°C | 50–100 mm | Boiler wall, superheater, reheater | 400–800°C | Ceramic fiber + calcium silicate | 128 / 220 | ~0.052 / ~0.060 @350°C | 150–200 mm | Economizer, main steam | 250–400°C | Ceramic fiber | 128 | ~0.052 @350°C | 80–120 mm | Mid-temp steam, feedwater | 150–250°C | Glass wool or rock wool | 48 / 120 | 0.040 / 0.045 @250°C | 80–120 mm | Low-temp steam, feedwater | < 150°C | Microporous (aerogel) or glass wool | 200 / 48 | 0.021 / 0.034 @25°C | 30–50 / 50–80 mm | Low-temp water, trace heating | Special (vibration, explosive atm.) | Ceramic fiber or high-density rock wool | 128 / 160 | 0.060 / 0.050 @400°C | 100–120 mm | Hydrogen-cooled piping, turbines | Material Selection by Site Condition - Vibration (turbines, compressors): flexible ceramic fiber or rock wool with pinned, multi-layer construction. - Wet or outdoor service: choose hydrophobic options — microporous boards reach ≥ 99% water repellency; rock wool is naturally hydrophobic. - High temperature and pressure: ceramic fiber blanket, or the ceramic-fiber/calcium-silicate composite where casing strength matters. Energy Savings and Payback The payoff is direct. On a 400°C steam line, moving from a thin, degraded layer to the ~150 mm economic thickness typically cuts surface heat loss from roughly 550 W/m² toward 300 W/m² — on the order of 150,000–200,000 kWh saved per year on a single line. Because insulation is cheap relative to fuel and the equipment it protects, payback on well-specified power-plant insulation commonly lands well inside the plant's operating life. Regular inspection matters: a damaged or compressed layer loses far more than its rated value, so a scheduled check-and-repair program protects both efficiency and safety. Related products: Calcium Silicate Insulation Board, Ceramic Fiber Rope, Glass Wool Board, Ceramic Fiber Plus Blanket, Refractory Ceramic Fiber Blanket — Ceramic Fiber Blanket Insulation Related applications: Environmental & Dust Removal, Power Generation, Nuclear Power FAQ: Q: What is the best insulation for power plant piping? A: It depends on temperature. Main and reheat steam lines (350–540°C) use a ceramic fiber + calcium silicate composite at 150–200 mm. Feedwater and low-temperature lines (150–250°C) use rock wool or glass wool at 80–120 mm. Always size by the economic-thickness method and check surface-temperature limits. Q: How thick should boiler insulation be? A: Radiant walls and arches above 800°C typically use ceramic fiber blanket at 50–100 mm. Economizer and superheater sections at 400–800°C use a ceramic-fiber/calcium-silicate composite of 150–200 mm to meet heat-loss and surface-temperature codes. Q: What insulation is used in combined cycle HRSG? A: HRSG casing, ducts, and stacks see gas-turbine exhaust at 400–600°C and are insulated with ceramic fiber blanket or a ceramic-fiber/calcium-silicate composite. The HRSG steam piping follows the same 150–200 mm composite rule as the main steam line. Q: How is insulation thickness calculated? A: Most plants use the economic thickness method — the thickness where added insulation costs more than the energy it saves. The result is capped by maximum allowable heat loss (around 110–130 W/m² for hot piping) and a surface-temperature limit of roughly 50–60°C. Q: Which insulation handles vibration on turbines? A: Flexible ceramic fiber or rock wool, 80–100 mm, pinned with stainless hardware at ≤ 250 mm spacing. Multi-layer construction resists fatigue and keeps the lining stable through decades of cyclic loading. ### Pyrogel vs Mineral Wool: Which to Choose? URL: https://www.rosetexwool.net/news/pyrogel-vs-mineral-wool/ 2026-08-19 | Author: Rosetex Wool Team | Category: industry insight Summary: Pyrogel vs mineral wool on cost per R-value and lifecycle payback for tanks, vessels and equipment: when aerogel pays back faster, and when mineral wool remains the value default. Pyrogel-type aerogel — the thin, high-efficiency blanket family most buyers mean when they search for "pyrogel" — is the most efficient industrial insulation per millimetre. Mineral wool (rock or glass) is the cheap, proven, high-temperature workhorse. They are not really rivals; they slot into different constraints. The practical question is rarely "which material is better" and almost always "which one is cheaper to own over the life of the plant" — and that depends on where the money actually goes. This article compares the two on cost per R-value, lifecycle cost and payback for general plant surfaces — tanks, vessels, equipment and ducts — where space is not the binding constraint. If your application is piping, see our dedicated pyrogel vs mineral wool pipe insulation comparison, which covers pipe racks, CUI and line-by-line economics. The Core Trade-off Factor | Pyrogel (aerogel) | Mineral Wool (rock / glass) | Thermal conductivity (25 °C) | 0.020–0.025 W/(m·K) | 0.034–0.044 W/(m·K) | Thickness for same R | roughly 1/3 to 1/2 | baseline | Max continuous service temp | about 650 °C (typical grade) | rock wool ~650–750 °C; glass wool ~350–450 °C | Density | 150–250 kg/m³ | 80–200 kg/m³ (common 100–150) | Hydrophobic behaviour | Inherently hydrophobic, breathable | Hydrophilic unless treated; relies on jacketing | Typical service life | 20+ years | 5–10 years in wet/cyclic service, 15–30 in dry | Material cost | 3–10× mineral wool | Lowest first cost | The last three rows — water behaviour, service life and cost — are where the lifecycle decision is actually made. Conductivity differences get most of the attention, but on a dry indoor tank the conductivity gap narrows to a thickness argument, while outdoors the water behaviour can decide whether the insulation is replaced once or three times in twenty years. The Real Cost Question: Price per R-Value, Not Price per Square Metre "Mineral wool is cheaper" compares the wrong unit. A square metre of 25 mm aerogel and a square metre of 25 mm mineral wool are not the same product — the aerogel carries roughly twice the thermal resistance. The fair comparison is cost per unit of R-value (thermal resistance) at the same surface temperature. Because aerogel needs only one-third to one-half the thickness for the same performance, the material premium is partially offset before installation even starts: you buy less volume, ship less weight, store less material and handle fewer layers. On an area basis aerogel is still the more expensive material — that does not change. But the gap is much smaller than the 3–10× multiple on a per-square-metre quote suggests, and on the next page of the cost sheet the thinner system starts saving money. Five Lines of a Lifecycle Cost Estimate A defensible comparison has five lines, not one: - Material cost — aerogel 3–10× per m³; mineral wool lowest. This is the only line where mineral wool wins outright. - Installation labour — aerogel is light and flexible: one person can carry a large roll, and it cuts with a knife around nozzles, brackets and irregular geometry. Mineral wool is heavier and rigid boards need cutting and fitting. On complex equipment the labour gap narrows or reverses the material gap. - Structure and support — at one-third to one-half the thickness and a fraction of the weight, aerogel reduces support steel, jacketing area and, on elevated or offshore work, the crane and scaffolding cost. Weight is a real money line on roofs, vessels and modules. - Energy loss over the operating life — the line that compounds. A small conductivity advantage on a surface that runs hot for years is worth more than any first-cost saving. This is the line that justifies aerogel on continuously hot process equipment. - Maintenance and replacement — mineral wool that gets wet loses performance and must be replaced; aerogel's hydrophobic structure survives wet–dry cycling. Where the outer jacket is likely to be damaged or opened repeatedly, this line can exceed the original material cost. Add the five lines over a 15–20 year horizon and the "cheap" material is not always the cheapest. On dry, protected, indoor surfaces mineral wool usually still wins the total; on wet, cyclic or repeatedly-maintained equipment aerogel frequently wins despite the 3–10× material multiple. When Aerogel Pays Back Faster The payback period for the aerogel premium is a function of three variables: operating hours, surface temperature and how often the insulation gets wet or damaged. Rough rules from plant practice: - Continuously hot process equipment (over ~6,000 operating hours per year at high temperature) — the energy-loss line compounds fastest. Payback on the premium is commonly in the 2–3 year range, after which aerogel is the cheaper material for the rest of its 20+ year life. - Outdoor, wet or coastal duty — every wet–dry cycle that would force a mineral wool replacement pays back part of the aerogel premium. Where mineral wool would be replaced even once before the first planned shutdown, the case flips early. - Retrofit where access, scaffolding or downtime is expensive — a thin single-layer aerogel system installs faster than a thick multi-layer mineral wool build. The saved shutdown hours can repay the material premium in a single outage. - Weight-sensitive locations — roof plant, vessel tops, offshore modules and structures near their load limit. Saving structural steel is saving money before the insulation ever carries heat. When none of these conditions apply — the surface is dry, indoor, warm rather than hot, and rarely opened — the payback stretches past a sensible horizon and mineral wool is the value answer. The decision is a payback calculation, not a brand preference. When Mineral Wool Is Still the Value Choice Mineral wool remains the smarter buy in the majority of general plant situations: - Large flat and curved surfaces — boiler casings, big ducts, tank roofs and walls where there is no shortage of space. Thick mineral wool is cheap and the extra thickness costs nothing but a few centimetres. - Dry, protected, indoor locations — the service-life penalty for mineral wool mostly disappears when the material never gets wet. - Acoustic duties — rock wool and glass wool are excellent sound absorbers; aerogel is not. Where noise control shares the specification, mineral wool does two jobs at once. - Budget-capped projects — when the first-cost line is a hard gate, mineral wool delivers acceptable performance for a fraction of the outlay, and the maintenance team can manage the water risk with good jacketing and inspection. - Broad availability — mineral wool is stocked locally in virtually every industrial region; aerogel is a specialist purchase with longer lead times (see below). For most plant insulation, rock wool blanket delivers the best cost per R-value in dry indoor service. Reach for aerogel when space, weight, water or operating hours make the lifecycle calculation favour the premium material. Above the aerogel temperature limit, step up to ceramic fiber blanket instead. Supply Chain and MOQ Realities Aerogel blanket is a specialist product: production is concentrated, lead times are longer, and minimum order quantities are higher than for mineral wool. Standard rolls come in set widths (typically around 1.2–1.5 m) and fixed thicknesses, so offcuts and wastage need planning on irregular jobs. Mineral wool, by contrast, is manufactured in every industrial country, stocked by distributors, and available in short lengths and odd quantities within days. Practical consequences for procurement: - Order aerogel early and in planned batches — combining several small requirements into one order improves both price and lead time. - Confirm the minimum order quantity with the supplier before design freeze — a project sized just under a MOQ threshold can be forced into a much larger purchase. - Check roll width against your largest flat surface — joining narrow rolls costs labour and creates seam risk; one wide roll is often cheaper than two narrow ones. - Budget for protective handling — aerogel compresses under point loads; storage and installation need care that mineral wool does not demand. None of these are blockers — they are planning items. But they explain why aerogel is specified deliberately for the surfaces where it pays, while mineral wool remains the default everywhere else. Our nano aerogel insulation blanket page gives the available widths, densities and service limits. Our Take Pyrogel-type aerogel and mineral wool are not competing versions of the same product; they are answers to different cost questions. Mineral wool is the value default for dry, spacious, indoor plant surfaces. Aerogel earns its premium where the operating hours, the water risk or the weight budget make the lifecycle total cheaper — and on those surfaces it is genuinely the lower-cost material over 20 years. Specify on a payback calculation, not on the per-square-metre quote. If you need a thickness starting point, our pyrogel insulation thickness guide provides charts by temperature and surface type. For piping-specific selection — pipe racks, CUI risk and line-by-line economics — see the pyrogel vs mineral wool pipe insulation comparison. Need a cost-per-R-value comparison for your actual surface temperature and operating hours? Contact our engineering team with the surface type, temperature and annual operating hours, and we will send back a five-line lifecycle estimate for both materials. Related products: Nano Aerogel Insulation Blanket, Rockwool Insulation Blanket (Rock Wool Blanket) Related applications: Building, Aerospace & Defense, Green Building & Retrofit FAQ: Q: Is Pyrogel better than mineral wool? A: For thinness and efficiency per mm, yes. For cost and general plant use, mineral wool wins. They suit different constraints, not a straight upgrade. Q: What temperature can Pyrogel withstand? A: Typical aerogel blanket grades serve up to about 650°C. Above that, use ceramic fiber (1000–1260°C) instead. Q: Why is aerogel insulation so expensive? A: Aerogel manufacturing is energy-intensive and low-volume; you pay for extreme thinness where space is the constraint. Q: Can mineral wool replace Pyrogel? A: On open surfaces, usually yes and far cheaper — just thicker. In tight pipe racks where space forbids the thickness, aerogel is the practical choice. Q: What is the payback period for aerogel insulation? A: On equipment running over about 6,000 hours per year at high temperature, the premium commonly pays back in 2–3 years through reduced heat loss. On outdoor or coastal duty where mineral wool would need replacement after wetting, or on retrofits where downtime is expensive, payback can be much faster — sometimes in a single outage. It depends on operating hours, surface temperature and water exposure. Q: What is the cheapest alternative to Pyrogel? A: Mineral wool (rock wool or glass wool) is the cheapest alternative on dry, indoor surfaces with space to spare, and it adds acoustic absorption. Calcium silicate and ceramic fiber cover higher-temperature or load-bearing duties. Aerogel is worth its premium only where thickness, weight, water resistance or operating hours make the lifecycle total favour it. Q: Is Pyrogel available as a rigid board? A: Yes. The same aerogel insulation family is produced as rigid nano-aerogel boards for flat surfaces that need dimensional stability and a harder face, alongside the flexible blanket form for curved equipment and irregular geometry. Rigid forms suit tank walls, vessel heads and applications where the insulation must hold its shape under light load. Q: Does aerogel insulation have a minimum order quantity? A: Yes — aerogel blanket is a specialist product with higher MOQs than mineral wool. Standard rolls come in set widths and fixed thicknesses, so procurement should order early, batch small requirements into one order, and confirm the MOQ with the supplier before design freeze to avoid being forced into a larger purchase. ### Industrial Pipe Insulation Types: A Practical Guide URL: https://www.rosetexwool.net/news/industrial-pipe-insulation-types/ 2026-08-19 | Author: Rosetex Wool Team | Category: industry insight Summary: Pipe insulation comes down to temperature, medium, and form. Here is the material map by service range, plus the common forms and a quick selection rule. Three Variables Decide the Type Pipe insulation types are usually listed by material first. That ordering is why so many specifications end up with the right material in the wrong form. Picking pipe insulation comes down to three things: temperature, medium, and form. Get those right and the material almost selects itself. That is true, but it is not the whole job — and the missing part is where most specifications go wrong. Temperature narrows the material. Pipe diameter then decides whether that material can be supplied in the form you assumed, and maintenance access decides whether the form you chose survives its first shutdown. A header that will never be opened again and a valve that gets stripped twice a year do not want the same construction, even at the same temperature. Temperature sets the material family, and it is the one variable nobody forgets. The other two are the ones that get missed. Diameter sets the form. Preformed pipe sections are produced against fixed tooling in standard bores; outside that range the realistic options are wrapped blanket, cut board, or a made-to-order shell, and both price and lead time move once you leave the standard range. Access sets the construction at fittings. Anything that will be opened is a different engineering problem from anything that will not, and it should be specified separately rather than left to site practice. This guide works through all three variables, then covers the four decisions that remain once the material is settled: preformed sections or wrapped blanket, single layer or double, what to do at fittings, and when a removable cover pays for itself. Selecting by Service: Temperature and Medium Material selection for pipe insulation starts with temperature, because it eliminates most of the field immediately. Band | Range | First choice | Usual form | Note | Cryogenic | −200 °C to −50 °C | Cellular glass, aerogel, multilayer | Preformed section with a sealed vapour barrier | Outer surface must stay above dew point | Low | −50 °C to +250 °C | Glass wool | Pipe section or blanket | Chilled water, HVAC, condensate return | Medium | +250 °C to +650 °C | Rock wool | Pipe section | Steam, thermal oil, most process lines | High | +650 °C to +1000 °C | Calcium silicate | Preformed section or board | Rigid; needs expansion allowance | Ultra-high | +1000 °C to +1400 °C | Ceramic fiber | Wrapped blanket or vacuum-formed shape | Furnace, reformer and kiln services | In practice rock wool pipe insulation covers the largest share of industrial metreage, because most process lines sit in the medium band. Two rules override the table. First, specify against the peak, not the normal operating point — a 600 °C line that sees 800 °C upsets belongs in the ceramic fiber row, not the rock wool row. Second, thermal cycling matters as much as absolute temperature: a line that swings several hundred degrees twice a day will fatigue a rigid system long before it reaches its temperature limit, and a wrapped blanket tolerates that movement better. The medium sets the failure mode more than the material does. Steam drives water through any gap in the barrier, and wet insulation has lost most of its value. Thermal oil wicks and, above roughly 250 °C, begins to burn the organic binder out of a wool product — which is one reason the medium band starts where it does. Cryogenic service almost never fails inside the insulation; it fails at the vapour barrier, and it fails at the supports and valve bodies first. The Four Construction Types at a Glance Four constructions carry nearly all industrial pipe insulation, and they are not interchangeable. Pipe insulation types are easier to shortlist once diameter and access are settled, which is what this section is about. Construction | Built from | Where it wins | Where it loses | Preformed pipe section | Rigid or semi-rigid, split into two half shells | Straight runs on standard bore; fastest install, uniform density | Non-standard outside diameter, very large bore, short runs where tooling cost dominates | Wrapped blanket or roll | Flexible, wired or banded on | Large bore, irregular geometry, field-fitted work | Exposed weather without a jacket; low compressive strength | Board or slab | Rigid | Flat equipment, vessels, large-diameter duct | Anything curved below roughly 600 mm diameter | Removable cover | Textile-encased mattress, strapped or laced | Valves, flanges, instruments — anything opened on a schedule | Permanent straight runs: costs more per metre and insulates slightly worse | Choosing between pipe insulation types is mostly a diameter and access question rather than a thermal one, which is why the next three sections matter more than the table above. For the full material comparison behind these four, including the jointing and weatherproofing detail, see our industrial pipe insulation materials guide. Preformed Pipe Sections: The Default for Standard Bore Preformed pipe sections are the default pipe insulation on standard bore, and for good reason. A preformed pipe section is a half shell moulded to a specific inside diameter and wall thickness, supplied in pairs, banded over the pipe, and finished with the jacket. Where the bore is standard, it is the best answer available: the density is uniform, the inner face sits tight against the pipe with no compression loss, and installation is quick because there is nothing to cut or size on site. That tight fit is the whole argument for preformed pipe insulation. Heat loss through a pipe insulation system is governed by the insulation only when the fit is right; a gap at the inner face sets up a convection loop that bypasses the material altogether. Sections also hold their thickness under banding, which a compressible blanket does not. The catch is that sections are produced against tooling — one mould per combination of nominal bore and wall thickness. That is simultaneously their advantage and their limit. Where Preformed Sections Stop: Diameter, Tooling and Non-Standard Sizes Three situations push a pipe insulation specification off preformed pipe sections, and none of them have anything to do with temperature. Very large bore. Above roughly DN 600 to DN 900, depending on the mill, half shells get heavy and fragile to handle, and the tooling cost per metre is hard to justify for a single run. Most large-diameter specifications switch to wired blanket, or to board segments cut and banded on site. Non-standard outside diameter. Older pipe schedules, non-metric sizes, thick-walled process pipe, and jacketed or traced lines all have outside diameters that fall between standard tooling sets. A section whose inside diameter is larger than the pipe leaves a circumferential gap, and the convection loop is back — on hot service that shows up as a hot jacket, and on cold service as sweating and corrosion under insulation. Short runs and one-off sizes. If a project needs twelve metres of one size, the tooling charge may cost more than the insulation. The working rule is simple: a circumferential fit gap of up to about 5 mm is acceptable; anything larger should not be packed with offcuts. Change the form instead and wrap with blanket, which conforms to whatever diameter is actually there. And confirm the mill can produce the inside diameter and wall thickness you need rather than assuming the standard range covers it. Wrapped Blanket and Roll for Large Bore and Irregular Geometry Blanket is often treated as the fallback when it is the better pipe insulation answer from the start. It conforms to any diameter, cuts with a knife, needs no tooling, and absorbs thermal movement that would crack a stiff shell — which makes it the default for large bore, elbows, tees and anything field-fitted. Two things have to be specified or the installed result will not match the calculation. First, state the thickness at a stated compression. Blanket is compressible; an enquiry that only says "50 mm" will be supplied at nominal thickness and installed at something less, and the heat loss will run higher than designed. Second, blanket has almost no compressive strength and no weather resistance of its own — it needs banding at regular centres and a metal or polymeric jacket outdoors, with sealed laps. Where the duty is hot and the geometry is awkward, ceramic fiber blanket covers the ultra-high band and rock wool blanket covers the medium band in exactly this form. Single Layer or Double Layer Pipe insulation thicker than about 75 mm is almost always built in two layers. Thickness is set by the heat-loss or surface-temperature limit, and the number of layers follows from the thickness. - Up to about 50 mm — a single layer is normal and cheaper. - 50–75 mm — either works; single layer if the mill stocks that thickness, two if not. - Above about 75 mm, or any service above roughly 400 °C — specify a double layer. There are three reasons to go double even when a single thick section exists. Joints get staggered, so no joint runs straight through the insulation to the pipe wall. A double layer also lets the two layers be different materials, which is the economic argument: put the expensive high-temperature material on the hot face at reduced thickness, and a cheaper, lower-conductivity material outside it where the temperature is already lower. And thick rigid shells in one layer crack more readily under thermal movement. The field rule for multi-layer pipe insulation that actually matters: stagger longitudinal joints by at least 200 mm between layers, and stagger the circumferential joints as well. A straight-through joint is a heat-loss path on hot service and a condensation path on cold service. Worth saying explicitly: adding layers is not adding thickness for its own sake. The thickness should come out of an economic-thickness calculation — the point where the marginal cost of another millimetre exceeds the value of the heat it saves over the life of the line. Layer count is then simply the practical way of delivering that thickness. Fittings, Valves and Flanges Fittings are where pipe insulation most often stops, and where the heat loss concentrates. An uninsulated valve body loses several times more heat than an equivalent length of bare pipe, simply because of its surface area and its mass of metal, and it stays hot enough to be a contact hazard. - Elbows take either mitred blanket cuts or preformed elbow shells. Mitring is faster on site and cheaper on short runs; shells hold their thickness at the outside of the bend and look better on visible lines. - Tees and reducers are usually built up from blanket and banded, or boxed out with board and jacketed. - Valves and flanges have to stay accessible. Either fit a removable cover, or box the item in a sealed, banded enclosure that is understood to be cut away and replaced at each opening. - Supports, shoes and hangers are the classic thermal bridge. Insulation should be interrupted at the support rather than compressed through it, and cold service needs a load-bearing insert that carries the load without carrying the heat. The failure pattern is consistent enough to be worth designing against: the straight run is well insulated and the fittings are not. Walk any plant and the bare spots are elbows, valve bodies and support shoes. Two practical notes. Mitred blanket work is the usual source of thin spots, because an offcut that is slightly short still looks acceptable once the jacket is on — specify the finished thickness at the outside of the bend, not only on the straight. And on cold service, every penetration of the vapour barrier at a support or an instrument connection has to be sealed as carefully as the barrier itself, because that is where the water gets in. Removable Insulation Covers as a Designed System Removable pipe insulation exists for one reason: some points have to be opened again. A removable cover is not a bag tied around a valve. It is a small engineered assembly with four parts, and all four belong in the specification: - Inner liner — a textile rated above the service temperature, because it sits against the hot face. - Insulation mattress — sized and quilted so it holds its thickness instead of slumping to the bottom of the jacket after two heat cycles. - Outer textile — rated for weather, ultraviolet exposure and any chemical contact on site. - Closure — lacing hooks, straps or buckles rated for the number of removal cycles expected, not merely for the first fit. Four more items separate a cover that stays in service from one that is left off after the first shutdown: handling weight per piece (keep it under about 15 kg so one person can manage it), labelling so each part returns to the same location, drainage on outdoor vertical runs, and spares — order roughly one spare per ten covers. The economics of removable pipe insulation are straightforward. Where a valve or strainer is opened twice a year, the labour saved stripping and rebuilding a fixed box pays for the cover within the first or second outage. The same logic is why covers are increasingly supplied with an inspection port or an embedded temperature sensor, turning an insulation check into something that can be done without a shutdown. Rock Wool Pipe Section: Spec Ranges by Temperature Rock wool pipe insulation carries the medium band, and these are the ranges a rock wool pipe section specification normally works within. Rock wool pipe also has a practical advantage on site: it is A1 non-combustible and naturally water-repellent, so it tolerates a wet trade sequence better than most alternatives. Parameter | Typical range | Why it matters | Density | 80–180 kg/m³, most often 100–150 | Higher density for load, vibration and ovalisation resistance | Wall thickness | 25–200 mm, standard stock 30–100 mm | Built up in layers above about 75 mm | Inside diameter | 18–1500 mm | Non-standard sizes are made, but lead time follows | Continuous service | to about 650 °C | Above that, move to calcium silicate or ceramic fiber | Fibre diameter | 4–6 µm | Finer fibre gives lower conductivity and more dust | Shot content | ≤ 12 %, premium grades ≤ 7 % | Non-fibrous particle; affects handling and conductivity | Hydrophobicity | ≥ 95 %, ≥ 98 % for hot-humid service | Water repellency retained after exposure | Chloride content | < 0.05 % | Required over austenitic stainless steel | Density is the lever most pipe insulation specifications under-use. Specifying the right density and compressive grade costs almost nothing, and it prevents the most common field failure on large-diameter lines: sections ovalising under their own weight between supports. For how these numbers are produced — melt temperature, fibre formation, binder dosing and curing — see rock wool pipe insulation: specs, production and selection. Product ranges: rock wool pipe insulation for the medium band, calcium silicate pipe above it, and glass wool blanket for chilled and HVAC duty. What to Put on a Pipe Insulation Enquiry Most pipe insulation quotes are inaccurate for the same reason. Most of them come from an enquiry that specified the material and nothing else. These fields close the gap: - Actual outside diameter and nominal bore — not the DN alone - Operating temperature, peak temperature, and the cycling profile - Medium, plus whether the line runs indoors, outdoors or buried - Required thickness, or the heat-loss / surface-temperature limit to design against - Jacketing material and finish - Fittings schedule — count of elbows, tees, valves and flanges, not just total metres - Access points — what has to be opened, and how often - Vapour barrier requirement on any chilled or cryogenic service - Quantity per size, broken out rather than given as one total Every one of these fields changes which pipe insulation types can actually be quoted. The last two are the ones most often missing, and they are the two that move the price the most. For a full-site view spanning distillation, cracking, storage and heat-traced services, see our petrochemical plant insulation guide. And once the unit duty is known, the construction-level choices behind it are covered in our unit-by-unit refinery and reformer insulation guide companion. Related Reading - Is glass wool fireproof? A1 non-combustible rating explained - Power plant insulation: materials & thickness by system - Rock wool for marine & offshore engineering: applications & benefits - Best heat-resistant materials for furnace (2026 guide) - Marine fire insulation: materials & standards (SOLAS) - Rock wool slabs for building, industrial & HVAC insulation - Industrial pipe insulation materials: the full comparison - Cryogenic pipe insulation: vapour barriers and cold service detail - Aerogel vs mineral wool for pipe insulation Related products: Calcium Silicate Pipe, Rockwool Pipe Insulation for Steam Pipes Related applications: Cement, Building, Iron & Steel, Marine & Offshore FAQ: Q: What are the types of industrial pipe insulation? A: By material: glass wool, rock wool, calcium silicate, ceramic fiber, and dedicated cryogenic systems. By construction: preformed pipe sections, wrapped blanket or roll, board or slab, and removable covers. Which construction applies depends less on temperature than on pipe diameter and on how often the line has to be opened. Q: What insulation for 600 °C steam pipes? A: Rock wool (continuous to about 650 °C) or, for margin and rigidity, calcium silicate or ceramic fiber above that. Q: Glass wool or rock wool for pipes? A: Both are A1 non-combustible. Rock wool holds the medium band to about 650 °C and is naturally water-repellent, which is why it dominates steam and thermal-oil lines. Glass wool is lighter and cheaper for the low band to roughly 250 °C — chilled water, HVAC and condensate return — with high-temperature grades running above that. Q: What insulation for cryogenic pipes? A: Dedicated low-temperature systems — cellular glass, aerogel, multilayer constructions — covering roughly −200 °C to −50 °C, always with a sealed vapour barrier. Not the high-temperature wools. The cold end fails at the barrier, the supports and the valve bodies long before it fails in the insulation itself. Q: Is rock wool the most common industrial pipe insulation? A: Yes, for most industrial lines. Rock wool pipe sections are A1 non-combustible, rated to about 650–700 °C, naturally water-repellent, and the lowest-cost option in their temperature band — which is why they dominate steam, thermal-oil, and process lines. Ceramic fiber takes over above ~650 °C, and calcium silicate where rigid load-bearing insulation is needed. Q: When should I use blanket instead of preformed pipe sections? A: Use preformed sections on standard-bore straight runs — they install faster and hold their thickness. Switch to blanket above roughly DN 600, on any non-standard outside diameter where the fit gap would exceed about 5 mm, and on short runs where tooling cost dominates the price. Blanket also handles thermal cycling better, because the fibre mat absorbs movement that cracks a rigid shell. Q: How should valves and flanges be insulated? A: Either with a removable cover or with a sealed, banded box intended to be cut away at each opening. A removable cover pays back wherever the item is opened more than once a year. Specify the liner temperature rating, a quilted mattress that will not slump, an outer textile rated for weather and ultraviolet exposure, a closure rated for the number of removal cycles, and handling weight under about 15 kg per piece. ### Is Glass Wool Blanket Waterproof? (A1 + Hydrophobic) URL: https://www.rosetexwool.net/news/is-glass-wool-blanket-waterproof/ 2026-08-19 | Author: Rosetex Wool Team | Category: industry insight Summary: Glass wool blanket is hydrophobic by nature but not a waterproofing membrane. Here is where it works, where it fails, and how it compares to rock wool in damp plant rooms. A waterproof glass wool blanket — in the membrane sense — does not exist. Glass wool blanket is hydrophobic by nature but not "waterproof" in the absolute sense. The glass fibers themselves do not absorb water, and most industrial grades are treated with a water-repellent additive — so the blanket shrugs off rain and condensation during storage and install. But the resin binder and trapped air gaps mean it should not sit submerged or face constant driving rain without a weatherproof jacket. Why Glass Wool Resists Water The fibers are spun from molten glass, which is inherently non-absorbent. Combined with a hydrophobic treatment, a quality glass wool blanket typically shows less than 1% water uptake by volume (short-term immersion, per EN 1609). That is why you see it specified on roofs, HVAC ducts, and plant pipework in humid environments. When It Is NOT Enough - Outdoor, unsheltered: UV and rain degrade the binder over time. Use a PVC or aluminium jacketing, or a dedicated outdoor grade. - Below-grade or submerged: glass wool is not a waterproofing layer — waterproofing belongs to a separate membrane. - High humidity plus heat: above about 400°C the binder chars. Glass wool is capped at 400°C service temperature anyway (operating range −120°C to 400°C). Glass Wool vs Rock Wool in Wet Areas Both are A1 non-combustible. Rock wool is naturally more water-repellent and holds its shape better when wet, which is why specifiers often pick rock wool blanket for genuinely damp plant rooms. For most dry-to-moderate indoor HVAC and equipment, glass wool blanket is the lighter, cheaper choice. Quick Spec Recap - Classification: Euroclass A1 non-combustible - Service temperature: −120°C to 400°C - Thermal conductivity: about 0.036 W/m·K - Water uptake: under 1% by volume (treated grade) See the full glass wool insulation guide for product ranges and application notes. Discover our building and facade insulation applications for external walls, facades, and roofing envelopes. Related products: Glass Wool Blanket, Rock Wool Blanket with Glass Fiber Mesh Related applications: Building, Green Building & Retrofit FAQ: Q: Is glass wool blanket waterproof? A: Not fully. The fibers are hydrophobic and treated grades repel water (under 1% uptake by volume), but it is not a waterproofing membrane and needs jacketing outdoors or in sustained wetness. Q: Does glass wool absorb water? A: Bare glass fibers do not absorb water; the hydrophobic treatment keeps uptake under about 1% by volume. The resin binder, not the glass, is the weak point under sustained wetness. Q: Can glass wool be used outside? A: Only with a weatherproof jacket (metal or PVC) or as a designated outdoor grade. UV and rain break down the resin binder over time. Q: Glass wool or rock wool in damp plant rooms? A: Rock wool is naturally more water-repellent and holds its shape when wet; glass wool wins on weight and cost for dry-to-moderate indoor use. ### Marine Fire Insulation: Materials & Standards (SOLAS) URL: https://www.rosetexwool.net/news/marine-fire-insulation-materials-standards/ 2026-08-19 | Author: Rosetex Wool Team | Category: industry insight Summary: Marine fire insulation keeps A-class and H-120 divisions within SOLAS/IMO limits. Rock wool is the workhorse; ceramic fiber covers hot uptakes. Material + class map. Marine fire insulation keeps a ship's A-class divisions, engine-room boundaries, and exhaust uptakes within SOLAS/IMO temperature limits during a fire. The workhorse material is rock wool — A1 non-combustible, dimensionally stable, and a decent acoustic absorber. Ceramic fiber steps in where exhaust or uptakes run hot, and calcium silicate board adds a rigid backup layer on load-bearing boundaries. Getting the specification right means understanding three things at once: what the SOLAS class actually measures, which materials can carry it, and how much thickness and density each position on the vessel needs. What SOLAS / IMO Demand A-class bulkheads and decks must limit the temperature rise on the unexposed side to 139 °C above ambient, with no point exceeding 180 °C, during the standard fire test. That is a thermal-duty spec, not just "non-combustible." The Standard Fire Test Curve Behind Every Marine Fire Rating Every marine fire insulation duty — A-15, A-30 or A-60 — is measured against the IMO standard time-temperature curve, and that curve is far more aggressive than first-time specifiers expect. Furnace temperature climbs steeply in the opening minutes, then flattens out: Time from ignition | Internal furnace temperature | Start | 20 °C (initial furnace temperature) | 5 minutes | 576 °C | 10 minutes | 679 °C | 15 minutes | 738 °C | 30 minutes | 841 °C | 60 minutes | 945 °C | The practical consequence: most of the temperature jump happens in the first five minutes. An insulation that survives 900 °C steady-state can still fail an A-60 test if heat crosses it fast enough during that opening ramp, because the assembly is judged on what happens on its unexposed face minute by minute — not on whether it survives the peak. Test geometry is fixed as well. The bulkhead or deck specimen presents an exposed area of not less than 4.65 m², with a height (or deck length) of 2.44 m, built to resemble the actual construction and including at least one joint. That joint is there on purpose: it is where real divisions fail. A-Class Divisions: A-15, A-30, A-60 and H-120 SOLAS classifies fire divisions by how long they contain a standard fire. The class number is the minutes the division holds both integrity (no flame or gas passage) and insulation (temperature-rise limits). Class | Smoke & flame integrity | Temperature rise held for | Max single-point rise (unexposed face) | Typical location | A-0 | 60 minutes | Not required | No limit | Control stations, stairway boundaries with low fire load | A-15 | 60 minutes | 15 minutes | 180 °C | Light-risk bulkheads, some corridor boundaries | A-30 | 60 minutes | 30 minutes | 180 °C | Accommodation-to-service boundaries | A-60 | 60 minutes | 60 minutes | 180 °C | Engine-room boundaries, stairway enclosures, galleys | H-60 / H-120 | 60 / 120 minutes | 60 / 120 minutes | 180 °C | Offshore modules and high-speed craft | Read that table carefully, because one point is misread constantly: the number in the class is not how long the division holds back flames. Every A-class division resists smoke and flame for a full 60 minutes. The number is the thermal duty — how long the unexposed face stays inside the 139 °C average / 180 °C single-point limits. That is why an A-0 division still has to be built from steel or an equivalent material, and why A-60 cannot be met simply by making a boundary thicker at random. The temperature limits themselves apply to the unexposed side measured above the original temperature: an average rise of no more than 139 °C (rounded to 140 °C in several references) across the face, and no more than 180 °C at any single point including any joint. B-Class and C-Class Divisions: What Changes Outside A-Class Not every fire boundary on a vessel is A-class. Accommodation linings, ceilings and internal doors mostly fall into B-class, and C-class appears where only non-combustibility matters. Aspect | A-class | B-class | C-class | Construction | Steel or equivalent material | Recognised non-combustible materials | Approved non-combustible materials | Flame integrity | Prevent smoke and flame for 60 minutes | Prevent flame for 30 minutes | No requirement | Max average temperature rise | 139 °C above original | 139 °C above original | No limit | Max single-point rise | 180 °C above original | 225 °C above original | No limit | Classes available | A-0, A-15, A-30, A-60 | B-0, B-15 | n/a | Typical use | Engine rooms, machinery spaces, stairways, galleys | Cabin linings, corridor and public-space boundaries | Minor internal partitions, joinery cores | Two details drive material selection here. First, B-class permits a higher single-point limit (225 °C against 180 °C), because a B-class division is not protecting against a fully developed machinery-space fire. Second, A-, B- and C-class profiles must all be built from non-combustible material — defined in the IMO Fire Test Procedures (FTP) Code as a material that neither burns nor gives off flammable vapours in sufficient quantity for self-ignition when heated to approximately 750 °C. That 750 °C threshold explains why lightweight organic-bonded or foamed products generally cannot serve as the core of a marine fire insulation assembly, no matter how well they perform in architectural fire tests. Which Division Class Goes Where: Ship Space Matrix Marine fire insulation specs start from SOLAS, which assigns a required class to every boundary according to the fire risk of the spaces on both sides. The pattern below reflects the standard requirement set for accommodation and service layouts; the vessel's approved fire control plan always governs on a specific ship. Boundary between | Typical required class | Machinery space ↔ accommodation, corridor, stairway or control station | A-60 | Galley ↔ accommodation space | A-60 | Galley ↔ corridor | A-30 | Control station ↔ stairway or corridor | A-0 | Control station ↔ accommodation space | A-60 | Stairway ↔ accommodation space | A-0 | Corridor ↔ cabin | B-15 | Cabin ↔ cabin | B-15 to C-class (non-combustible) | Machinery space ↔ machinery space | A-0 where risk is equal, A-60 where separation is required | Pump room ↔ accommodation or machinery space | A-60 | Cargo hold ↔ accommodation or machinery space | A-60 on gas and chemical carriers; A-0 to A-30 for dry cargo | Read the logic rather than memorising the cells. Boundaries around a machinery space, a galley, or any space with both a high fire load and ignition sources are A-60. Boundaries between two similar low-risk accommodation spaces step down to B-class. Everything else sits between those two poles, which is why the same ship will carry four different division classes within a few metres of structure. H-120 Marine Insulation H-120 is the 120-minute fire-resistance class required on offshore modules, high-speed craft, and installations where evacuation takes longer than one hour. It is a stricter thermal duty than A-60: the same 139 °C / 180 °C temperature-rise limits, but held for two hours instead of one. In practice, H-120 divisions use higher-density rock wool board or ceramic fiber — typically thicker, installed over a steel substrate with certified cladding — sized so the unexposed face stays within limits for the full 120 minutes. If you are specifying H-120, request the approved product test certificate (IMO FTP Code Part 3) rather than relying on catalog ratings. Marine Fire Insulation Thickness and Density by Ship Space Once the class is fixed, marine fire insulation thickness and density follow from the duty. The figures below are typical starting points for budgeting and space planning on new builds and refits — the type-approved certificate for the chosen system sets the final numbers. Ship location | Typical class | Insulation form | Typical thickness | Typical density | Engine-room bulkhead | A-60 | Rock wool board | 80–100 mm | 150–180 kg/m³ | Engine casing / funnel casing | A-60 to A-30 | Rock wool board with cladding | 60–100 mm | 120–150 kg/m³ | Exhaust uptake and silencer casing | Hot-side layer | Ceramic fiber blanket | 25–50 mm | 128–160 kg/m³ | Galley boundary | A-60 | Rock wool board | 80–100 mm | 150–180 kg/m³ | Stairway enclosure | A-60 to A-0 | Rock wool board | 0–100 mm | 100–150 kg/m³ | Accommodation ceiling and bulkhead lining | B-15 | Rock wool board | 40–50 mm | 120–150 kg/m³ | Corridor lining | B-15 | Rock wool board | 40–50 mm | 100–120 kg/m³ | Steel deck carrying load | A-60 | Calcium silicate backup plus rock wool | 30–50 mm each | 220–1000 kg/m³ (calcium silicate) | Pipe and cable penetration | Same as parent division | Certified penetration seal | Per approval | Per approval | Two things stand out in that table. First, an A-60 duty takes roughly twice the thickness in an engine room as it does in accommodation, because the same temperature-rise limit has to hold four times longer against a much hotter neighbouring space. Second, the exhaust uptake is the one row where ceramic fiber replaces rock wool, because metal temperatures on the gas side routinely run past what a 650 °C-rated stone wool product can hold continuously. Weight Trade-offs: Density Costs Money Afloat Marine fire insulation mass matters more at sea than ashore. Every kilogram above the waterline affects stability, draught and fuel burn, so a single fire class often has two or three defensible solutions at different densities. Build-up | Approximate mass per m² | When it earns its weight | 50 mm rock wool at 120 kg/m³ | ~6 kg/m² | B-15 accommodation linings with short fire duty | 100 mm rock wool at 150 kg/m³ | ~15 kg/m² | A-60 boundaries that also need to block machinery noise | 50 mm ceramic fiber at 128 kg/m³ | ~6.4 kg/m² | Exhaust uptakes above continuous stone wool limits | 25 mm calcium silicate at 250 kg/m³ | ~6.3 kg/m² | Load-bearing backup where compression resistance dominates | Optimising downward only works if the type-approved system allows it. Going below the tested thickness is never permitted — the saving has to come from choosing a form that meets the identical duty with less mass, not from trimming the build that was actually tested. Marine Fire Insulation Material Comparison Five materials carry almost every marine fire insulation duty. The right choice is a function of three things: the division class you must meet, the continuous service temperature the position actually sees, and whether the boundary has to carry load. Material | Continuous service | Division reach | Typical density | Where it wins | Rock wool blanket | ~650 °C | A-15 → A-60 | 60–150 kg/m³ | Default A-class divisions; fire plus acoustic | Rock wool board | ~650 °C | A-30 → H-120 | 100–200 kg/m³ | Rigid bulkheads, decks, H-class boundaries | Ceramic fiber blanket | 1000–1260 °C | H-60 / H-120 hot side | 96–160 kg/m³ | Exhaust uptakes, incinerator casings, penetrations | Calcium silicate board | 900–1050 °C | A-60 backup, H-class | 220–1000 kg/m³ | Load-bearing backup on steel boundaries | Glass wool | 250–350 °C | B / C-class only | 12–48 kg/m³ | Accommodation acoustics, HVAC, low fire duty | Two things decide most of these calls. First, temperature: glass wool is an acoustic material, not a fire-division material, and it is only admissible where the division duty is low. Second, rigidity: calcium silicate is chosen not for its conductivity but because it holds shape under compression on a steel boundary where rock wool would slowly compact. Thickness by Division Class Thickness is not a free variable. For a certified division the build is fixed by the approved system — insulation type, density, thickness, cladding and fixing method all together. The figures below are typical starting points for budgeting and space planning, not a substitute for the certificate. Division | Typical build | Common locations | B-15 / C-class | 25–50 mm glass or rock wool | Accommodation internal partitions | A-15 | 40–60 mm rock wool (~80 kg/m³) | Light-risk bulkheads, corridor boundaries | A-30 | 60–80 mm rock wool (~100 kg/m³) | Accommodation-to-service boundaries | A-60 | 75–100 mm rock wool (~120 kg/m³) | Engine-room boundaries, stairway enclosures | H-60 | 100 mm+ high-density rock wool or ceramic fiber | Offshore module steel, high-speed craft | H-120 | 120–150 mm+ certified system | Offshore modules with long evacuation times | Note how the step from A-60 to H-120 is not simply "twice the time, twice the thickness." It changes the material: H-class duties usually move to higher-density rock wool board or add a ceramic fiber hot-side layer, because the same 139 °C / 180 °C temperature-rise limit has to hold for two hours instead of one. Fire-Resistant Marine Materials The materials accepted for marine fire divisions share three properties: A1 non-combustibility, low smoke and toxicity per the IMO FTP Code, and a continuous service temperature above the duty: - Rock wool blanket and board — the default for A-class divisions and accommodation boundaries. A1, service to about 650 °C continuous, naturally water-repellent, good for both fire and noise. See rock wool blanket and rock wool board. - Ceramic fiber blanket — for hot spots: exhaust uptakes, incinerator casings, and high-temperature penetrations where rock wool would break down. Continuous use to 1000–1260 °C. See ceramic fiber blanket. - Calcium silicate board — the rigid, load-bearing backup on steel boundaries. A1, dimensionally stable, holds its shape under compression. See calcium silicate insulation board. - Glass wool — lightweight acoustic insulation for accommodation and HVAC areas where the fire duty is lower (B/C-class divisions). Each of these families is covered in more depth in its own material hub: rock wool insulation, ceramic fiber insulation, calcium silicate insulation and glass wool insulation. Beyond Fire Resistance: Smoke, Toxicity and Surface Flammability Fire resistance attracts most of the attention, but a marine fire insulation product has to clear several other tests before it is admissible on a vessel. The IMO FTP Code separates them deliberately: - Part 1 — non-combustibility. The material must neither burn nor give off flammable vapours in sufficient quantity for self-ignition when heated to approximately 750 °C. Without this result the material cannot form part of an A-, B- or C-class division at all. - Part 2 — smoke and toxicity. The smoke released during combustion is measured for optical density and toxic gas concentration. On a ship, incapacitation from smoke inhalation is a larger casualty mechanism than heat, and escape routes pass through the same compartments. - Part 5 — surface flammability. Exposed surfaces must demonstrate low flame spread, so a fire in a corridor does not propagate along the lining itself. - Part 3 — fire resistance of divisions. The assembly-level test that produces the A-15 / A-30 / A-60 or B-15 duty. The practical trap is this: a product can hold a valid Part 3 certificate for a concealed engine-room bulkhead and still be inadmissible as a corridor lining, because corridor applications additionally require Part 2 and Part 5 results. When reviewing a datasheet, check all four parts rather than only Part 3. Our A1 non-combustible insulation guide covers how European classifications relate to these marine requirements. Marine vs Offshore: Two Different Rulebooks One clarification that saves confusion on mixed projects. This guide covers shipboard fire insulation under SOLAS — A-class bulkheads, decks and accommodation boundaries on vessels, where the duty is defined by SOLAS Chapter II-2 and tested to the IMO FTP Code. Offshore platforms work to a different framework. Module boundaries are rated H-60 / H-120 and are sized against hydrocarbon fire curves (ISO 834) and, where a high-pressure release is credible, jet fire (UL 1709) — with the thickness driven by the steel section factor as much as by the fire duration. That is passive fire protection engineering rather than shipboard insulation, and it is covered separately in our offshore fireproofing guide. If your project is an FPSO or a floating unit, you may well need both: SOLAS A-class divisions in the accommodation block, and H-class PFP on the process modules. Where It Goes Marine fire insulation appears in five positions on almost every vessel: engine-room and machinery-space boundaries (A-60 down to A-15), exhaust uptakes and silencer casings (ceramic fiber territory), accommodation ceilings and corridor linings where fire duty and noise control overlap, pipe and duct penetrations through fire divisions, and offshore module boundaries rated H-60 or H-120. Penetrations, Joints and Fixings: Where Divisions Actually Fail Marine fire insulation only performs as part of a certified division, and installed systems fail at discontinuities far more often than through the insulation layer itself. Three details consistently decide whether the installed division behaves like the tested specimen: - Penetration seals must match the parent division. A pipe passing through an A-60 bulkhead requires an A-60-rated seal, tested for the same pipe material, diameter and contents. Substituting an unrated sleeve is among the most common survey findings. - Joints carry their own duty. The standard test specimen deliberately includes at least one joint, because that is where gap gauges find openings. Panel fixing centres belong to the certificate, not to installer judgement. - Fixings have to survive the fire. Pins, washers and hangers form part of the tested construction. Non-rated fixings soften well before 60 minutes and let insulation slump away from the substrate, exposing bare steel to the furnace. How to Write a Marine Fire Insulation Specification "A-60 rock wool" is a product description, not a marine fire insulation specification, and it will not survive plan review. A defensible line item names five things: - The class and location — A-60 engine-room bulkhead, frames 40 to 52, port side. - The product and its form — rock wool board rather than blanket; nominal density 150 kg/m³. - The thickness and compression limit — 100 mm single layer, compressed no more than the approved percentage at fixing points. - The cladding or facing — sheet material and thickness exactly as tested. - The fixing method and centres — pin type, washer size, spacing, plus the type-approval certificate number the assembly belongs to. Close the item with the certificate reference and the approval body recognised by the vessel's flag state. If any one of the five changes during construction, treat it as a re-approval rather than a substitution. Practical Notes - Pair insulation with certified cladding or jacketing rated for the division. - Watch compression: over-compressed rock wool loses R-value and can open fire paths. - On hot uptakes, ceramic fiber modules outperform blanket for vibration and thermal cycling. - Verify the IMO FTP Code certificate for the exact product and thickness; the classification society audits the installed system, not the catalog spec. - On A-60 boundaries specifically, work from a full heat-balance rather than a catalog thickness — our A-60 marine insulation guide walks through the calculation. IMO FTP Code Part 3: What the Certificate Actually Covers This is the part that causes the most expensive rework. An A-60 certificate is issued for an approved system, not for a material. The IMO FTP Code Part 3 fire test qualifies a complete assembly: the insulation product, its density, its thickness, the cladding or facing, the fixing method and spacing, and the supporting steel. Change any one of those and the certificate no longer applies — even if the insulation itself is unchanged. In practice that means: - A catalog "A-60 rating" is a claim about one tested configuration, not a property of the product. - Substituting a different density of the same rock wool product usually invalidates the approval. - The certificate is audited by the classification society against the installed system, not against the datasheet. When you specify, ask for the certificate for the exact product, density, thickness and cladding being installed, and confirm the approval body is recognised by the vessel's flag state. For EU-flagged vessels this normally also means the Marine Equipment Directive wheel mark; US-flagged vessels look for USCG approval. Five Specification Mistakes We See on Marine Fire Insulation 1. Specifying the material instead of the system. "A-60 rock wool" is not a specification. The certificate defines the assembly — density, thickness, cladding, fixing. Write all four into the spec. 2. Over-compressing the insulation. Rock wool loses thermal performance when compressed beyond its design density, and compression can open gaps that become fire paths. Fixing centres matter as much as the insulation itself. 3. Treating penetrations as an afterthought. Pipes, cables and ducts passing through a fire division are the most common failure point in both testing and service. The penetration seal has to be rated for the same division as the bulkhead it passes through. 4. Mixing densities within one division. A boundary built partly at 80 kg/m³ and partly at 120 kg/m³ has not been tested in either configuration. Consistency is not cosmetic. 5. Substituting cladding to save weight or cost. Cladding is part of the tested system. Swapping a facing without re-testing is one of the fastest ways to fail a class survey. Acoustic Performance On most vessels the same insulation is doing two jobs. Accommodation boundaries, corridor ceilings and HVAC runs need fire performance and noise control, and rock wool is usually the material that satisfies both — it is porous enough to absorb sound and dense enough to meet A-class fire duties. Where acoustics dominate and the fire duty is low (B/C-class), glass wool is lighter and cheaper and performs better per kilogram on absorption. Where fire dominates, rock wool board is the safer call. Ceramic fiber is a poor acoustic material and is not chosen for noise control. For the thermal and acoustic side of the same question — pipe thickness, condensation control, NRC targets and HVAC zones — see our marine insulation thermal and acoustic specification guide. Related Reading - A-60 Marine Insulation: How It Works + Thickness Guide - Offshore Fireproofing: Passive Fire Protection on Platforms - Rock Wool Insulation for Marine & Offshore Engineering - Marine Insulation: Thermal & Acoustic Specifications - Non-Combustible Insulation Systems: A1 Fire Rating Explained - What Temperature Can Rock Wool Withstand? - Marine & Offshore Insulation Applications - Rock Wool Insulation Hub · Ceramic Fiber Insulation Hub · Calcium Silicate Insulation Hub For a focused look at engine rooms and machinery spaces, see our Ship Engine Room & Machinery Space A-60 insulation guide. Related products: Calcium Silicate Pipe, Ceramic Fiber Modules, Glass Wool Blanket, Ceramic Fiber Plus Blanket Related applications: Marine & Offshore FAQ: Q: What insulation is used for marine fire protection? A: Primarily A1 rock wool for A-class divisions and accommodation; ceramic fiber for hot exhaust uptakes and penetrations where rock wool would break down. Q: What temperature must marine fire insulation withstand? A: SOLAS/IMO limit the unexposed surface to 139°C above ambient (max 180°C) in the standard fire test — a thermal-duty limit, not just non-combustibility. Q: Is rock wool allowed on ships? A: Yes. Rock wool is A1 non-combustible and the standard choice for marine A-class divisions; it is also naturally water-repellent, useful in engine rooms. Q: Rock wool or ceramic fiber for exhaust uptakes? A: Ceramic fiber — uptakes run hot enough to break rock wool down (rock wool caps near 650°C continuous). Ceramic fiber serves 1000–1260°C. Q: What is H-120 marine insulation? A: H-120 is a 120-minute fire-resistance class required on offshore modules and high-speed craft. It applies the same temperature-rise limits as A-60 (139°C average / 180°C maximum on the unexposed side) but holds them for two hours instead of one, typically with higher-density rock wool or ceramic fiber over a steel substrate. Q: What materials are fire-resistant for marine use? A: Rock wool (A1) is the workhorse for A-class and H-120 divisions; ceramic fiber covers hot exhaust uptakes to 1260°C; calcium silicate board adds a rigid load-bearing backup; glass wool serves lower-duty acoustic areas. All must meet the IMO FTP Code smoke and toxicity limits. Q: What does A-0 mean on a ship fire division? A: An A-0 division still resists smoke and flame for a full 60 minutes, but it carries no requirement to limit temperature rise on the unexposed face. It must be built of steel or an equivalent material, and it is used around control stations and stairways where the adjacent spaces have a low fire load. Insulation may be omitted, but the boundary itself remains non-combustible. Q: How thick is marine fire insulation for an A-60 engine-room bulkhead? A: Typically 80-100 mm of rock wool board at 150-180 kg/m³. The exact figure belongs to the type-approved system rather than to the product: the certificate covers a specific density, thickness, cladding and fixing pattern together, so altering any one of those outside the approved assembly voids the approval. Q: Does marine fire insulation need more testing than fire resistance? A: Yes. Beyond Part 3 fire resistance of the division, the IMO FTP Code also assesses non-combustibility at approximately 750 °C (Part 1), smoke and toxicity (Part 2), and surface flammability (Part 5). Concealed engine-room boundaries may rely mainly on Part 3, but linings in escape routes and accommodation spaces generally require results from all four parts. ### Is Glass Wool Fireproof? Yes — A1 Non-Combustible URL: https://www.rosetexwool.net/news/is-glass-wool-fireproof/ 2026-08-17 | Author: Rosetexwool Editorial | Category: industry insight Summary: Glass wool is A1 non-combustible — it won't burn or spread flame. Rated -120°C to 400°C, it's fire-safe for buildings yet not a high-temperature insulation. Is Glass Wool Fireproof? (Short Answer) Yes — glass wool is non-combustible and carries the highest European fire class, A1. The glass fibers themselves do not burn, and bonded glass wool rolls or boards contribute no fuel to a fire. It will not ignite, drip, or spread flame. That said, "fireproof" and "high-temperature" are different things. Glass wool is fire-safe but has a moderate service-temperature ceiling of about 400°C (752°F). For furnace or process-heat duty you need a higher-rated material such as rock wool blanket (up to 750°C) or ceramic fiber. See our glass wool blanket for the full specification sheet. Glass Wool Fire Rating: A1 (Euroclass) Glass wool is classified Euroclass A1 — non-combustible, the same top rating as rock wool. In fire tests it: - Does not ignite or sustain combustion - Releases no significant smoke or flaming droplets - Retains its form far longer than combustible foams or plastics This makes it suitable for fire-rated building assemblies, HVAC ducts, and cavity barriers where non-combustibility is required by code. Why Glass Wool Does Not Burn Glass wool is made by spinning molten glass into fine fibers. Glass is already a fired, inorganic material — it cannot burn. Two points matter for real-world use: - The fibers: Inorganic glass softens and melts around 600–700°C. It does not combust. - The binder: Rolls and boards use a thermosetting resin binder. The binder can char above roughly 250–300°C, which is why the rated continuous service limit is about 400°C, not the glass melting point. Even as the binder degrades, the material still does not catch fire. Glass Wool Temperature Range: -120°C to 400°C Property | Glass Wool | Fire class | A1 non-combustible | Continuous service temp | -120°C to 400°C | Glass softening point | ~600–700°C (melts, does not burn) | Thermal conductivity | λ 0.036 W/m·K | The A1 rating is one class in the European scale. For how that scale is built — A1 through F, the s1-s3 smoke and d0-d2 droplet suffixes, and what each test measures — see our Euroclass fire classification system explained. Glass Wool vs Rock Wool: Fire Resistance | Glass Wool | Rock Wool | Fire class | A1 non-combustible | A1 / Class A (fireproof) | Max service temp | ~400°C | ~750°C | Melting point | ~600–700°C | ~1000°C+ | Best for | Buildings, HVAC, ducts | Buildings + higher-heat process | Both are A1 non-combustible, so both are "fireproof" in the fire-safety sense. The difference is temperature ceiling: rock wool tolerates roughly double the heat, which is why it is chosen for closer-to-source thermal duty. See our glass wool blanket for full specifications. Fire rating is only one part of the specification. For the full procurement view — supplier audit, density selection and the enquiry checklist — see our glass wool insulation buyer's guide. When Glass Wool Is NOT the Right Choice Because its ceiling is ~400°C, glass wool is not a high-temperature insulation. Avoid it for: - Furnace linings and kilns - Exhaust and flue gas streams above 400°C - Continuous process piping above its service limit For those, step up to rock wool blanket (≤750°C) or ceramic fiber blanket (up to 1260–1430°C). For a broader A1 vs A2 vs B fire rating comparison across insulation families, see the dedicated guide. See our traffic and fire-protection insulation applications for tunnels, transit, and A1 fire-rated passive protection. Related products: Glass Wool Blanket Related applications: Building, Green Building & Retrofit FAQ: Q: Is glass wool fireproof? A: Yes. Glass wool is **A1 non-combustible** — it does not burn, ignite, or spread flame. Its continuous service limit is about **400°C**; above that the binder can char but the glass fibers still will not combust. Q: What fire rating does glass wool have? A: Glass wool carries **Euroclass A1**, the highest non-combustibility rating in European standards — the same class as rock wool. It emits no significant smoke or flaming droplets in fire tests. Q: At what temperature does glass wool melt? A: The glass fibers soften and melt around **600–700°C**. However, the resin binder that holds rolls and boards together begins to break down above ~250–300°C, which is why the rated continuous-use temperature is about **400°C**. Q: Is glass wool better than rock wool for fire? A: Both are **A1 non-combustible**, so neither burns. Rock wool wins on **temperature ceiling** (~750°C vs ~400°C) and is preferred closer to heat sources, while glass wool is the cost-effective choice for buildings and HVAC. Q: Can glass wool be used for furnace insulation? A: No. With a ~400°C service limit, glass wool is not a high-temperature material. For furnaces, kilns, and hot flues use [rock wool](https://www.rosetexwool.net/products/rock-wool-blanket/) (≤750°C) or [ceramic fiber](https://www.rosetexwool.net/products/ceramic-fiber-blanket/) (up to 1430°C). Q: What does non-combustible glass wool mean? A: It means the material passes the non-combustibility test — EN 13501-1 class A1 or the equivalent GB 8624 A1 — and contributes no heat, flame, or fuel to a fire. Glass wool does not burn; at very high temperature the fibers soften and melt rather than ignite. Q: Is glass wool fire safe? A: For fire propagation, yes: glass wool is A1 non-combustible and will not ignite or spread flame. The practical limit is thermal, not fire — sustained service above about 350–538°C carbonizes the binder and weakens the material, so above that range rock wool or ceramic fiber is the safer spec. ### Calcium Silicate vs Ceramic Fiber Board: Which to Choose URL: https://www.rosetexwool.net/news/calcium-silicate-vs-ceramic-fiber-board/ 2026-08-16 | Author: Rosetexwool Editorial | Category: industry insight Summary: Calcium silicate board vs ceramic fiber board: compare temperature limits, strength, thermal conductivity, and cost to pick the right refractory board for furnace linings. When you need a rigid refractory board for furnace lining, the choice usually comes down to calcium silicate board or ceramic fiber board. Both are A1 non-combustible and widely used in industrial insulation, but they behave very differently under load, temperature, and thermal cycling. The short answer: pick calcium silicate insulation board for structural, moisture-resistant backup insulation below 1100°C; pick ceramic fiber board for lightweight hot-face linings up to 1430°C. Below is the side-by-side breakdown. Material Properties Compared Temperature limit and thermal stability Property | Calcium Silicate Board | Ceramic Fiber Board | Continuous service temperature | ≤1050°C (peak 1100°C) | Up to 1430°C | Thermal shock resistance | Moderate; can crack under rapid cycling | Excellent; handles frequent start/stop cycles | Density | 200–1200 kg/m³ (grade dependent) | 200–300 kg/m³ | Typical compressive strength | ≥1.0 MPa | ≥0.5 MPa standard; enhanced grades higher | Calcium silicate (also called calsil) keeps its rigidity and strength at moderate temperatures, making it ideal for load-bearing backup layers. Ceramic fiber board is much lighter and far more tolerant of thermal shock, but standard grades are lower in mechanical strength. Thermal conductivity Both boards insulate well, but the temperature curve matters: - Calcium silicate board: thermal conductivity stays relatively flat across the working range, around 0.04–0.06 W/(m·K) at elevated temperatures. That makes it predictable for steady-state industrial processes. - Ceramic fiber board: conductivity increases with temperature (roughly 0.09 W/(m·K) at 400°C rising to ~0.18 W/(m·K) at 1000°C). Despite the rise, its extremely low thermal mass reduces heat storage and improves fuel efficiency in cyclic furnaces. Chemical stability - Ceramic fiber board resists most acids and alkaline slags, especially zirconia-enhanced grades. Avoid strong alkalis and direct contact with phosphate or hydrofluoric acid. - Calcium silicate board tolerates moisture, weak acids, and salt-laden atmospheres. It is not suitable for strong acid environments such as phosphoric or hydrofluoric acid service. For the full property set behind the calcium silicate column — composition, density bands and grade ratings — see our calcium silicate insulation guide. Where Each Board Wins Application | Recommended board | Why | Furnace hot-face, thermal cycling | Ceramic fiber board | High temp + shock resistance, fast heat-up/cool-down | Kiln backup layer, structural support | Calcium silicate insulation board | High compressive strength, dimensional stability | Moist or fire-rated partitions | Calcium silicate board | Moisture resistant, A1 fire rating, long static life | Petrochemical heaters and reformers | Ceramic fiber board | Lightweight modules, easy to replace damaged sections | Ship bulkheads, substations, building fire barriers | Calcium silicate board | Fire rating + humidity tolerance | Cost, Installation and Service Life Initial cost: calcium silicate board is generally the lower-cost option per square meter for equivalent thickness. Ceramic fiber board costs more upfront, especially high-purity or zirconia grades rated above 1400°C. Installation: ceramic fiber board is easy to cut on site and can be supplied as pre-engineered modules, cutting rebuild time by 30% or more. Calcium silicate board is heavier and usually needs sawing, drilling, and expansion-joint detailing. Service life: - Calcium silicate board: 30–50 years in static, protected service. - Ceramic fiber board: 5–10 years on a hot face with severe cycling; longer in cooler backup positions. When whole-life cost is calculated (material + labor + energy + downtime), ceramic fiber board often wins in high-temperature cyclic furnaces because the energy savings and shorter outage windows offset the higher purchase price. Decision Framework Use this four-question filter: - Is the continuous temperature above 1050°C? → Ceramic fiber board is required. - Does the lining carry structural load or need moisture resistance? → Calcium silicate board is safer. - Will the equipment cycle frequently? → Ceramic fiber board handles thermal shock better. - Is first cost or 30-year cost driving the project? → Calcium silicate for low first cost; ceramic fiber for lowest total cost of ownership. For complex furnaces, the two materials are often combined: ceramic fiber board on the hot face, calcium silicate insulation board behind it as a rigid, insulating backup. For furnace lining duty specifically — hot face against back-up, batch cycling, gas velocity and slag contact — the four questions above are only the start: see our refractory board selection guide for the full duty assessment. Beyond furnace linings, the same two families are being specified for molten salt heat storage and battery enclosures, where service temperature and cycling are set by the storage cycle rather than by a production campaign: our LDES 2026 report on long-duration energy storage insulation covers that application. Related Reading - Ceramic Fiber vs Rock Wool for Furnace Linings - Best Heat-Resistant Materials for Furnace (2026 Guide) - What Temperature Can Rock Wool Withstand? Related products: Refractory Ceramic Fiber Board for High Temperature Insulation, Calcium Silicate Insulation Board Related applications: Cement, Power Generation FAQ: Q: What is the main difference between calcium silicate board and ceramic fiber board? A: Calcium silicate board is a rigid, high-strength backup insulation with excellent moisture resistance up to 1100°C. Ceramic fiber board is a lightweight, thermally shock-resistant hot-face insulation rated up to 1430°C. Q: Can calcium silicate board replace ceramic fiber board above 1100°C? A: No. Standard calcium silicate board is limited to 1050°C continuous service and 1100°C peak. Above that temperature, ceramic fiber board or polycrystalline fiber products are required. Q: Which board is better for furnace hot-face lining? A: Ceramic fiber board is usually better for hot-face linings because it withstands higher temperatures, handles rapid thermal cycling, and has low thermal mass for faster heat-up and cool-down. Q: How long does each board last in industrial service? A: Calcium silicate board can last 30–50 years in static, protected backup insulation. Ceramic fiber board typically lasts 5–10 years on a severe hot face with thermal cycling, and longer in cooler positions. ### What Temperature Can Rock Wool Withstand? (≤650°C Continuous, ~1000°C Melting) URL: https://www.rosetexwool.net/news/what-temperature-can-rock-wool-withstand/ 2026-08-15 | Author: Rosetexwool Editorial | Category: industry insight Summary: What temperature can rock wool withstand? Continuous service ≤ 650°C, sintering limit ~1000°C. A1 fire rating and rock wool vs glass wool & ceramic fiber. Rock wool (also called mineral wool or stone wool) is one of the most widely used inorganic insulation materials in construction and industry. If you are specifying it for a project, the two numbers that matter most are its continuous service temperature and its melting (sintering) point — and they are not the same. This guide explains both, with the real figures behind rock wool's temperature limit, A1 non-combustibility, and how it compares with glass wool and ceramic fiber. Rock Wool Temperature Rating & Melting Point Rock wool's long-term safe service temperature runs from cryogenic temperatures up to ≤ 650 °C, depending on product type, density, and binder. - Standard rock wool: continuous-use ceiling of ≤ 650 °C. As an inorganic fiber it stays mechanically stable far below freezing, so the practical lower limit is set by moisture management rather than the fiber itself (see the cold-end section below). - High-density basalt rock wool (≥ 120 kg/m³): engineered to hold ≤ 650 °C reliably for long duty cycles on industrial piping and thermal equipment. - Short-term / sintering limit ≈ 1000 °C: at roughly this temperature the fibers begin to sinter — they lose elasticity and structural stability, and properties such as thermal conductivity and compressive strength degrade. The material can briefly see ~1000 °C, but it must not be specified for sustained service there. Rule of thumb: treat ≤ 650 °C as the working ceiling and ~1000 °C as the structural / sintering limit. Anything above 650 °C for sustained duty calls for ceramic fiber. Rock Wool Insulation Blanket (Rock Wool Blanket) is the typical flexible form for wrapping pipes, ducts, and equipment within this temperature band. Melting Point vs Continuous Service Temperature This is the distinction most specifiers miss. "Melting point" and "continuous service temperature" describe two completely different limits: Term | What it means | Rock wool figure | Continuous service temperature | The temperature the material can run at indefinitely for insulation duty without losing performance | ≤ 650 °C | Sintering / structural limit | The temperature at which fibers begin to soften, shrink, and lose structure | ≈ 1000 °C | Melting point (true melt) | The temperature at which the mineral fully liquefies | well above 1000 °C (not a usable limit) | Why it matters: a material's melting point is not its operating temperature. Insulation is never run at its melting point — doing so would mean the fibers have already begun to sinter and fail. The number that belongs in a specification is the continuous service temperature (≤ 650 °C for rock wool), with the sintering point (~1000 °C) treated only as an absolute upper boundary for transient excursions. The same logic applies to fire ratings. The A1 non-combustibility test (EN ISO 1182) exposes a rock wool sample to a 750 °C furnace — a test condition, not a service temperature. Rock wool passes because it neither burns nor contributes to fire growth, even under that test heat. Don't read the 750 °C test furnace as a working limit; the working limit stays at ≤ 650 °C. What Does A1 Fire Rating Mean? The A1 fire rating is the highest classification in the EN 13501-1 European standard for the reaction to fire of building products — it denotes a completely non-combustible material that contributes nothing to a fire. (An equivalent non-combustibility grade exists under other regional standards; EN 13501-1 is the most widely referenced in international projects.) To earn A1, rock wool must pass the EN ISO 1182 non-combustibility test with: - Furnace temperature rise ≤ 30 °C - Mass loss ≤ 50% - Sustained burning time t = 0 (no combustion) - Gross heat of combustion PCS ≤ 2.0 MJ/kg (rock wool is usually far below this) - No smoke toxicity (t0 class) - No burning droplets (d0 class) Rock wool achieves A1 because it is composed entirely of inorganic mineral fibers. Basalt rock wool with an acid coefficient (MK) ≥ 1.7 retains its structural integrity through the 750 °C test furnace. The continuous service temperature of ≤ 650 °C sits well inside this fire-test envelope — which is exactly why rock wool is trusted as a fire barrier. For load-bearing and fire-rated assemblies, Rock Wool Board — Stone Wool Slabs provides the rigidity and dimensional stability needed. Rock Wool vs Glass Wool vs Ceramic Fiber (Temperature) Rock wool sits between glass wool and ceramic fiber on the temperature scale — making it the right choice for mid-to-high-temperature duty. Material | Long-term service temp | Short-term limit | Fire rating | Typical applications | Rock wool | ≤ 650 °C | ~1000 °C (sintering) | A1 | Building exterior walls, fire barriers, industrial pipe insulation, marine | Glass wool | −120 °C to ~400 °C | ~500–700 °C | A1 | Interior walls, steel-roof decks, HVAC ducts, acoustic | Ceramic fiber | 1100–1430 °C | 1600–1900 °C | A class | Industrial kilns, high-temp piping, power boilers, refining equipment | Versus glass wool: glass wool's long-term limit is about −120 to 400 °C. Above 400 °C its thermal conductivity climbs sharply and its binder carbonizes between 300–500 °C, destroying structural strength. Glass wool is lighter, but it cannot match rock wool in sustained high-temperature service. For a full breakdown of whether glass wool burns and its A1 non-combustible rating, see our dedicated guide. Versus ceramic fiber: ceramic fiber serves 1100–1430 °C continuously with almost no shrinkage, but it is brittle. Rock wool's temperature ceiling is lower, yet its mechanical strength is higher — better for load-bearing structures — and its natural hydrophobicity keeps performance stable in humid environments. Above 650 °C for sustained duty, step up to ceramic fiber. For steam and process lines, Rock Wool Pipe Insulation is engineered for the ≤ 650 °C band. What Affects Rock Wool's Temperature Resistance Four factors decide how close to the limit you can safely run: - Raw material — basalt vs slag: Basalt rock wool (SiO₂ 45.8–55.7 wt%, Al₂O₃ 13.2–19.1 wt%) sustains up to 650 °C. Slag-based wool, higher in CaO/MgO, typically caps lower and tends to powder and disintegrate at high temperature. The difference traces to the acid coefficient (MK): basalt MK ≥ 1.8 versus slag MK ≤ 1.5. - Acid coefficient (MK = (SiO₂+Al₂O₃)/(CaO+MgO)): MK ≥ 1.8 gives better heat and chemical stability (up to 650 °C); MK ≥ 2.0 improves water and corrosion resistance for humid, high-temperature duty. - Density and fiber structure: density normally spans 40–200 kg/m³; higher density means better heat resistance and lower shrinkage. High-density grades (100–140 kg/m³) hold dimension better, and fibers averaging ≤ 7 µm give higher compressive strength and heat-load temperature. - Binder type: conventional phenolic binders tolerate only ≤ 250 °C; switching to an inorganic binder (e.g., aluminum silicate) lifts the product ceiling above 600 °C. Binder content should stay ≤ 3.0% — too much undermines heat performance. Relevant product and test standards to ask for: EN 13162 (manufactured mineral wool products for buildings), EN 14303 (industrial insulation), EN ISO 1182 (non-combustibility), and EN 12667 / EN 12939 (thermal resistance). Cold End: How Low Can Rock Wool Go? Mechanically, rock wool is an inorganic fiber and remains stable at very low temperatures — there is no "cold melting point." The real limit at the cold end is moisture, not temperature. Rock wool is open-cell and hygroscopic. Below about −50 °C, and especially at LNG temperatures around −160 °C, any water vapor that reaches the insulation will condense and then freeze, destroying the insulation value and adding enormous thermal mass. So the practical cold-service rule is: a hydrophobic grade with a continuous vapour barrier and metal jacketing is the standard specification down to about −50 °C. Below that, rock wool moves to a secondary or insulated-jacket role and closed-cell materials take the primary duty — see the cryogenic insulation applications guide. Choosing the Right Rock Wool for Your Temperature - Building exterior walls: specify basalt rock wool with MK ≥ 1.8 and density ≥ 120 kg/m³ for long-term heat and fire performance. - Power-industry duty (boilers, turbines, duct linings): for system-level material selection and thickness, see our guide to rock wool in the power industry. - Industrial high-temperature piping: match density to the operating temperature; above 650 °C for sustained duty, step up to ceramic fiber. - Humid or wet environments: choose products with water-repellent rate ≥ 98% to prevent water uptake that raises thermal conductivity and lowers heat resistance. - Above 650 °C equipment: use high-density or basalt rock wool plus metal jacketing for structural stability; in sulfurous or alkaline atmospheres, validate performance with project-specific testing. - Cold service: a hydrophobic grade with continuous vapour barrier and metal jacketing is standard to about −50 °C; below that, see the cryogenic insulation applications guide. - Always request third-party test reports — acid coefficient, density, thermal conductivity, and fire-resistance rating — before purchase. Related Reading - Ceramic Fiber vs Rock Wool for Furnace Linings: Which to Choose - Best Heat-Resistant Materials for Furnace (2026 Guide) - Rock Wool Insulation Hub — stone wool boards for thermal & fire protection Related products: Rockwool Insulation Blanket (Rock Wool Blanket), Rockwool Pipe Insulation for Steam Pipes, rock Wool Strips Related applications: Cement, Cryogenic Insulation, Iron & Steel FAQ: Q: What temperature can rock wool withstand continuously? A: Standard and high-density basalt rock wool is rated for continuous use up to ≤ 650 °C. Short excursions toward ~1000 °C cause sintering (loss of structure), so 650 °C is the safe working ceiling for sustained service. Q: What is rock wool's melting point? A: Rock wool fibers begin to sinter (soften and lose structure) at about 1000 °C, so that is the practical structural limit rather than a true melt. The mineral itself melts at a much higher temperature, but above ~1000 °C the material should not be used for structural or insulating duty. Q: Is rock wool fireproof? What does A1 mean? A: Rock wool is A1 classified under EN 13501-1 — the highest non-combustibility grade. It does not burn, does not melt, and releases no toxic smoke or burning droplets (t0/d0). It contributes nothing to fire growth. The A1 test (EN ISO 1182) subjects it to a 750 °C furnace as a test condition, not a service temperature. Q: Rock wool vs glass wool — which withstands higher temperature? A: Rock wool by a wide margin. Rock wool serves ≤ 650 °C continuously (sintering ~1000 °C), while glass wool is limited to about −120 to 400 °C and its binder fails above 400–500 °C. Q: Rock wool vs ceramic fiber — which is better for high heat? A: Ceramic fiber wins on pure temperature (1100–1430 °C continuous) and shrinkage, but it is brittle. Rock wool's ceiling is ≤ 650 °C yet it has higher mechanical strength and natural water resistance, better for load-bearing and humid environments. Above 650 °C sustained, choose ceramic fiber. Q: What's the difference between rock wool's melting point and its continuous use temperature? A: They are different limits. The continuous service temperature (≤ 650 °C) is what you specify for ongoing duty; the sintering / melting point (~1000 °C) is where fibers begin to fail. Insulation is never run at its melting point, so the continuous-use figure — not the melting point — belongs in your specification. ### Best Heat-Resistant Materials for Furnace (2026 Guide) URL: https://www.rosetexwool.net/news/best-heat-resistant-materials-furnace-2026/ 2026-08-14 | Author: Rosetexwool Editorial | Category: industry insight Summary: A 2026 guide to the best heat-resistant furnace materials by temperature tier — ceramic fiber, calcium silicate, rock wool and aerogel, with pros, cons, and service-life data. Industrial furnaces span a huge temperature range — from low-temperature drying ovens below 200°C to continuous-process kilns running above 1400°C. The single most important factor in furnace design and relining is choosing heat-resistant materials for furnace walls that matches the operating temperature, load, and atmosphere. Pick wrong and you face collapsed linings, wasted energy, and unplanned shutdowns. This 2026 guide ranks the leading furnace-grade materials by temperature tier, with comparison tables, pros and cons, and real service-life data so you can specify the right lining the first time. How to Match Material to Furnace Temperature A core rule from refractory engineering: a material's continuous-service limit should sit 10–20% above the furnace's maximum operating temperature. A furnace peaking at 1000°C needs a material rated for at least 1100–1200°C. Below, materials are grouped into four practical tiers. Furnace Temperature Ladder: Match Material to Peak Temp The best heat-resistant materials for furnace lining are matched to the furnace's peak temperature in the ladder below. When a spec calls out a single peak temperature, use this ladder to pick the primary hot-face material and the backup that supports it. Each step is a practical rule of thumb — always leave a 10–20% margin above the furnace's maximum operating temperature. Furnace peak temp | Primary hot-face material | Backup / support layer | Typical form | ≤600 °C | Rock wool board; calcium silicate board | — (single layer often enough) | Rigid board, low cost | 1000 °C | Standard ceramic fiber (1260 °C grade) | Calcium silicate / rock wool board | Blanket or board | 1200 °C | High-alumina ceramic fiber (1360 °C grade) | Calcium silicate board | Pre-formed module | 1400 °C | Zirconia ceramic fiber (1430 °C grade) or high-alumina castable | Calcium silicate + ceramic fiber | Module + backup | 1600 °C | Polycrystalline mullite / high-alumina castable + brick | Ceramic fiber backup | PCW board hot face | The backup layer usually runs at 30–50% of the hot-face temperature, which is why a calcium silicate or rock wool backup stays perfectly adequate behind a 1300 °C ceramic fiber hot face. Selecting heat-resistant materials for furnace walls this way — by zone, not by furnace name — is what keeps a lining within budget. For the full composite-wall method, see the hot-face / backup section below. ≤600°C — Backup Layers & Low-Temperature Zones At the cold face and in low-temperature drying equipment, cost and conductivity matter more than raw heat resistance. Material | Max service temp | Thermal conductivity | Notes | Rock wool (stone wool) | ≤650 °C | 0.035–0.085 W/m·K | A1 non-combustible, rigid, cheap | Silica aerogel | 650–850°C | 0.016–0.030 W/m·K | Ultra-thin backup, premium cost | Rock wool is the workhorse backup layer: it is inexpensive, easy to cut, and performs well on conductivity below 600°C. Silica aerogel earns its place where space is tight — it delivers the same insulation in a fraction of the thickness. Neither belongs on a hot face above ~650°C. 600–1100°C — Load-Bearing & Mid-High Zones This is where most process furnaces, kilns, and reformers operate, and where calcium silicate insulation board becomes the material of choice for structural zones. Material | Max service temp | Thermal conductivity | Compressive strength | Calcium silicate board | 900–1050°C | 0.056–0.070 W/m·K | ≥0.55 MPa (load-bearing) | Standard ceramic fiber | 1000–1260°C | 0.025–0.050 W/m·K | Low (needs anchoring) | Silica aerogel (upper range) | 850°C | 0.016–0.030 W/m·K | Very low | Calcium silicate insulation board combines high compressive strength (≥0.55 MPa) with A1 non-combustibility and excellent dimensional stability — ideal for furnace floors, walls, and any zone that must carry load. Its main weakness is a higher thermal-expansion coefficient, so in frequent thermal-cycling designs it is often paired with ceramic fiber. 1100–1430°C — High-Temperature Hot Face Above 1100°C the lining must survive the flame zone. Ceramic fiber — especially as pre-formed ceramic fiber modules — dominates here. Material | Max service temp | Thermal conductivity | Key strength | Standard ceramic fiber | 1000–1350°C | 0.025–0.050 W/m·K | Low thermal mass, fast cycling | Zirconia ceramic fiber | 1350–1430 °C | ~0.025 W/m·K | Alkali / corrosion resistant | Nano-composite ceramic fiber | 1200–1400°C | 0.022–0.030 W/m·K | Best thermal-shock resistance | Ceramic fiber modules are anchored directly to the furnace shell, need no curing, and their very low thermal mass lets furnaces heat and cool faster — improving thermal efficiency by 15–20% versus heavy brick linings. In a typical petrochemical furnace lining, a ceramic fiber hot face is backed by calcium silicate or rock wool for a cost-efficient composite wall. Nano-composite ceramic fiber is the standout for thermal shock: in testing, modules retained 85%+ of compressive strength after 10 thermal cycles (1100°C → water quench), versus under 40% for traditional ceramic fiber — exactly what rotary kilns and frequent start-stop furnaces need. ≥1430°C — Ultra-High-Temperature & Special Applications For the hottest zones — semiconductor annealing, high-purity labs, and ultra-high-temp research — standard fibers are not enough. Material | Max service temp | Why it's used | Polycrystalline mullite fiber | 1900°C | Ultra-low shrinkage, high purity | Zirconia ceramic fiber | 1430 °C | Extreme alkali resistance | Carbon aerogel | 1800–3000°C | Frontier material, highest temp, very high cost | Polycrystalline mullite fiber board holds its structure with minimal shrinkage even at 1900°C and is the practical choice for ultra-high-purity furnaces. Carbon aerogel reaches 3000°C but remains a niche, high-cost option mostly outside mainstream industrial furnace specification. Ceramic Fiber Forms: Blanket, Board, and Module Among heat-resistant materials for furnace hot faces from 1100–1430 °C, ceramic fiber is the most-used, but it ships in three forms that are not interchangeable. - Blanket — a needled, flexible roll at 96–160 kg/m³. It conforms to irregular surfaces and is the standard backup and expansion-joint fill. Density grades run 1100 (common), 1260 (standard), 1360 (high-alumina) and 1430 °C (zirconia) classification temperature, with continuous-working temperatures about 10–20% lower. Ceramic fiber blanket is the workhorse for lining repairs and pipe wrapping. - Board — a rigid, machinable panel at 260–400 kg/m³. Use it where the lining must hold a shape: door liners, gaskets, burner blocks and expansion joints. It cuts cleanly and resists airflow erosion better than blanket. - Module — pre-compressed blocks anchored directly to the steel shell. Ceramic fiber modules are the dominant hot-face form for process furnaces: install is fastest, there is no curing step, and their very low thermal mass lets a furnace heat and cool far quicker than a brick or castable wall. For a head-to-head against rock wool in furnace duty, see Ceramic Fiber vs Rock Wool for Furnace Linings. Castable Refractory vs Ceramic Fiber: Choosing the Form Three lining forms dominate furnace construction, and they trade the same variables against each other: density, slag / load resistance, install speed and thermal mass. Form | Density | Slag / load duty | Install | Thermal mass | Best for | Fired brick | Highest | Best | Slow, jointed | High | Harshest hot faces, ladles | Monolithic castable | Medium–high | Good (low-cement) | Fast, jointless, pourable | High | Complex geometry, repairs | Ceramic fiber | Lowest | None (no load / slag) | Fastest | Tiny | Fast-cycling clean heat, backup | Castable refractory covers 1200–1800 °C and is the default for irregular shapes, transition zones and on-site pours — but its high thermal mass means a brick or castable furnace stores a lot of heat each cycle and needs 24–48 h of curing. Ceramic fiber is immune to thermal shock and reaches temperature almost instantly, but it cannot carry load or resist slag, so it is reserved for clean, low-velocity, lower-temperature duty or used as backup behind a dense face. Most real linings combine forms: a castable or brick hot face backed by ceramic fiber and calcium silicate. When you weigh heat-resistant materials for furnace duty, the form you pick matters as much as the chemistry. For board-level selection between calcium silicate and ceramic fiber, see Refractory Board Selection: Calcium Silicate vs Ceramic Fiber, and for the full material rating map see Refractory Insulation Materials: Types, Ratings & Applications. Bio-Soluble (AES) Fiber: A Safer Lower-Temperature Option Alkaline earth silicate (AES) wool — built on a calcium–magnesium–silica chemistry rather than alumina–silica — is a bio-soluble alternative to conventional ceramic fiber. It dissolves in body fluid and is exonerated from carcinogen classification under EU Directive 97/69/EC (Note Q), which removes the compulsory health-surveillance burden that traditional refractory ceramic fiber carries in EU and UK projects. AES fiber insulates comparably to standard ceramic fiber up to about 1200 °C (classification temperature 1300 °C) and typically carries a 5–15% material premium — but on regulated projects the eliminated monitoring and notification costs usually deliver a net saving. It is the right call for medium-temperature furnaces, appliances and any lining where installers work close to the material. The limit: above ~1200 °C continuous hot-face duty you still need ceramic fiber (high-alumina or zirconia grade) or castable. AES is a complement to, not a full replacement for, ceramic fiber in high-temperature furnaces. Pros & Cons by Material (Quick Comparison) Material | Temp ceiling | Strength | Cost | Best for | Rock wool | 650 °C | Medium (rigid) | Low | Backup, ≤600°C zones | Calcium silicate board | 1050°C | High (load-bearing) | Medium | Floors, load-bearing walls | Ceramic fiber | 1350°C | Low (needs anchor) | Medium-low | Hot face, thermal cycling | Nano-composite ceramic fiber | 1400°C | Low–medium | Medium-high | High thermal-shock zones | Silica aerogel | 850°C | Very low | High | Thin backup, space-limited | Polycrystalline mullite | 1900°C | Low–medium | High | Ultra-high-temp, pure atm. | Hot Face vs Backup: Getting the Composite Wall Right Very few industrial furnaces are lined with a single material. The standard construction is a layered composite, because the temperature the hot face sees and the temperature the backup sees are 300–600 °C apart — and paying hot-face prices for backup material is the most common way furnace budgets get wasted. Layer | Typical material | What it does | Hot face | Ceramic fiber modules / nano-composite fiber | Survives flame, thermal shock, low heat storage | Intermediate | Ceramic fiber blanket | Absorbs shrinkage, cushions the hot face | Backup | Calcium silicate board / rock wool board | Controls shell temperature, carries load | Shell | Carbon steel plate | Structure | The design rule that matters: specify each layer by the temperature it actually sees, not by the furnace's peak temperature. The backup layer typically runs at 30–50 % of hot-face temperature, which is why rock wool and calcium silicate are perfectly adequate behind a 1300 °C ceramic fiber hot face. Two details that get missed. First, anchoring: the metal anchors holding a fiber hot face must survive close to hot-face temperature, so they are alloy (310 stainless or equivalent), never carbon steel — anchor oxidation and creep is a leading cause of lining collapse. Second, shell temperature target: most specifications aim for 60–80 °C on the shell, which protects personnel and caps heat loss; that target is what actually sets backup thickness. Atmosphere Matters More Than Temperature A lining that fails at 1100 °C is rarely a temperature problem. In our experience it is more often the furnace atmosphere attacking a material that was correctly rated for the heat. Atmosphere | What it does | Safer choice | Oxidising | Mildest case; almost all fibers are stable | Standard ceramic fiber, calcium silicate | Reducing / hydrogen | Reduces SiO₂ to volatile SiO, causing fibre mass loss | High-alumina or alumina fiber, low-silica grades | Vacuum | Removes convective heat transfer; fibrous linings perform better | Ceramic fiber, polycrystalline fiber | Alkali vapour | Attacks alumino-silicate fibres, causing powdering | Zirconia ceramic fiber | Sulphur / chlorine bearing | Corrodes metal anchors before it attacks the fibre | Special alloy anchors, plus fibre review | This is why the same ceramic fiber that runs ten years in an air-fired heat-treatment furnace can fail in eighteen months in a reducing-atmosphere unit at 200 °C lower. When you specify, state the atmosphere alongside the temperature — a temperature-only spec is incomplete. Maintenance & Service Life Material choice decides not just first cost but how often you reline. Field data: - Rock wool loses strength above ~650°C and in high-temperature service can fail in under 3 years. - Ceramic fiber linings last 5–10 years with preventive care — e.g., a high-temperature hardener sprayed every 12 months. - Calcium silicate board is the longest-lived structural option, with a service life often cited at 50+ years in stable zones. - Silica aerogel composites typically deliver 15+ years with 60%+ heat-loss reduction. - Nano-composite ceramic fiber modules keep 85%+ strength after 10 severe thermal cycles. Maintenance best practices: spray ceramic fiber with a refractory hardener annually to reduce fiber shedding and dust; request third-party test reports (thermal shrinkage, shot content, fiber diameter) for every batch; and manage thermal shock in frequent-cycling furnaces by pairing fiber with calcium silicate. A rotary-kiln case using a calcium silicate + nano-ceramic-fiber composite cut shell temperature from 280°C to 205°C and reduced fuel use by 11.2% — a payback of about 6.5 years on a 50-year asset. Five Failure Modes and What Actually Causes Them 1. Shrinkage cracking. The single most common failure. The lining is operated above the material's continuous service limit rather than its short-term classification temperature, the fibres devitrify and shrink, and gaps open at the joints. Hot gas tracks through the gaps and attacks the shell. 2. Anchor failure. Metal anchors oxidise, creep, or were specified in the wrong alloy for the hot-face temperature. The lining stays intact but detaches. Almost always a specification error rather than a material defect. 3. Chemical attack. Alkali vapour, molten slag, or a reducing atmosphere degrades the fibre surface. The material was the right temperature grade and the wrong chemistry grade. 4. Mechanical damage. Charging impact, slag removal, and maintenance traffic break a rigid board or tear a blanket. Concentrated on lower walls, door surrounds and hearth edges. 5. Thermal shock spalling. Rapid heat-up or cool-down cracks rigid linings. The fix is usually a material change — ceramic fiber modules tolerate cycling that calcium silicate board does not — rather than a procedural one. Note that four of these five are specification problems, not material defects. That is why the temperature-tier tables above are built around continuous service limits, and why the polycrystalline mullite fiber board guide puts shrinkage data ahead of temperature headline numbers. How to Choose: A Decision Framework - Operating ≤600°C? → Rock wool or aerogel backup. - 600–1100°C, load-bearing? → Calcium silicate board. - 1100–1430°C hot face / frequent cycling? → Ceramic fiber modules (zirconia if alkali is present). - ≥1430°C, high purity? → Polycrystalline mullite fiber. - Large furnace? → Composite wall: fiber hot face + calcium silicate / rock wool backup. For most process and petrochemical furnace lining projects, the working lining is ceramic fiber with calcium silicate or rock wool behind it. Real-World Examples: Cement Kiln & Reformer Furnace Two common furnaces show how heat-resistant materials for furnace lining are combined in practice, zone by zone. Cement kiln. The burning / sintering zone sees material at ~1450 °C under a flame above 1800 °C, so the hot face runs on magnesia-based brick while the shell is protected by ceramic fiber and calcium silicate board backup. The preheater tower and calciner, running cooler, use refractory castable plus ceramic fiber linings. A full engineering walkthrough is in Cement Kiln Thermal Protection: Insulation Engineering. Steam methane reformer. The radiant box holds tube walls around 900–1100 °C. The lining is high-alumina or zirconia ceramic fiber modules on anchors, backed by calcium silicate, with castable at the harshest penetrations. Our Petrochemical Reformer Furnace Reline case study and the Refinery & Reformer Insulation unit guide cover the detail. Related Reading - Ceramic Fiber vs Rock Wool for Furnace Linings: Which to Choose - Refractory Board Selection: Calcium Silicate vs Ceramic Fiber - Cement Kiln Thermal Protection: Insulation Engineering - Petrochemical Reformer Furnace Reline — Case Study - Calcium Silicate Insulation: Board, Pipe & Panels For process-unit lining standards across furnaces, kilns and reactors, see our petrochemical furnace insulation guide. Related products: Rockwool Insulation Slabs — Rock Wool Board, Calcium Silicate Pipe, Refractory Ceramic Fiber Blanket — Ceramic Fiber Blanket Insulation, Ceramic Fiber Tape Related applications: Cement, Iron & Steel FAQ: Q: What is the best heat-resistant material for a furnace? A: It depends on temperature. For hot faces at 1100-1430°C, ceramic fiber (especially modules) is best; for load-bearing zones at 600-1100°C, calcium silicate board; for backup below 600°C, rock wool. Ultra-high-temp zones above 1430°C use polycrystalline mullite fiber. Q: What material can withstand 1000°C continuously? A: Standard ceramic fiber serves 1000-1260°C continuously, calcium silicate board to 1050°C, and high-purity alumina refractories higher still. Rock wool should not be used above about 650°C. Q: What material can withstand 1500°C or more? A: Polycrystalline mullite fiber board is rated to 1900°C with minimal shrinkage; zirconia ceramic fiber reaches 1350-1600°C; carbon aerogel up to 3000°C but at very high cost. Q: Is rock wool good for furnace lining? A: Only for backup and zones below about 650°C. Above that it loses strength and eventually melts near 1000°C, so the hot face must use ceramic fiber or refractory. Q: What is the difference between refractory brick, castable, and ceramic fiber lining? A: Brick wins the harshest hot faces and slag duty; castable wins install speed, complex geometry and most new linings; ceramic fiber wins fast-cycling clean heat and backup insulation because it has almost no thermal mass. Most real furnace linings combine more than one form across their layers. Q: Is bio-soluble fiber a replacement for ceramic fiber in furnaces? A: Only up to about 1200 °C. Bio-soluble (AES) fiber insulates like standard ceramic fiber and is safer to handle under EU and UK rules, but for continuous hot-face duty above 1200 °C you still need high-alumina or zirconia ceramic fiber, or a castable. It complements rather than replaces ceramic fiber at high temperature. ### Rock Wool External Wall Insulation: European ETICS Techniques URL: https://www.rosetexwool.net/news/rock-wool-external-wall-insulation-installation/ 2026-08-13 | Author: Rosetexwool Editorial | Category: industry insight Summary: ETICS rock wool external wall insulation guide: U-value and thickness, anchor wind-load calculation, horizontal fire barriers, condensation control and service life. Why European ETICS Practice Matters for Rock Wool Facades Rock wool is an A-class (non-combustible) high-performance insulation with a long, well-documented history in European External Thermal Insulation Composite Systems (ETICS). The maturity of its installation standards and quality-control discipline far exceeds what is common elsewhere. This article distils European practice — built on ETAG 004, EN 13500 and EN 17237 — into a practical reference for external wall insulation, covering how thick the board has to be, how many anchors a given wind zone actually needs, how horizontal fire barriers stop vertical flame spread, and what governs moisture behaviour over a 25-year service life, so that facade projects anywhere can adopt internationally proven methods. For the full material family behind this guide, see the rock wool insulation hub. The single most useful idea in external wall insulation is that the board is the least interesting part of the system. Bonded area, anchor pattern, fire-barrier continuity and the vapour path through the build-up decide whether a facade performs for twenty-five years or starts cracking and staining in five. Every number in this guide is a system number, and that is how a rock wool external wall should be specified. 1. System Build-Up and the Standards Framework European rock wool facade systems follow two pillars: the European Technical Assessment (ETA) route and the harmonised EN route. ETAG 004 is the certification core for rendered ETICS, while EN 13500 specifies performance requirements for mineral-wool-based systems. In 2022, EN 17237 (ETICS kits with rendered systems) was published, replacing EAD 040083-00-0404 and giving manufacturers more flexibility to tune components such as anchor spacing and render thickness within a defined field of application. Three basic build-ups dominate: - Double-mesh with disc-anchored mesh — substrate → levelling → adhesive → rock wool board → two glass-fibre mesh layers (one below, one above the anchor disc) → base coat → finish. Best for tall buildings needing high flatness and crack resistance. - Single-mesh with disc-anchored mesh — same sequence with one mesh layer. Lower cost, suited to less demanding flatness requirements. - Strip-anchored single mesh — uses rock wool lamellas (fibres perpendicular to the wall) with higher tensile strength, ideal for weak substrates. Disc diameter is the key differentiator: ≥ 60 mm in double-mesh systems, ≥ 140 mm in single-mesh systems, and ≥ 60 mm in strip-anchored systems. This sizing reflects how the anchoring system affects overall thermal and mechanical performance. 2. Thickness, U-Value and Thermal Bridging "How thick should external wall insulation be?" is the question specifiers ask first, and it is the one question a board datasheet cannot answer. Thickness is an output of a calculation that starts with the wall you already have, not with the insulation you would like to sell. The arithmetic runs in one direction. Convert the target U-value to a total thermal resistance: R = 1 / U. Subtract the resistances the assembly already provides — inner surface film (0.13 m²·K/W for horizontal heat flow), outer surface film (0.04 m²·K/W), and the existing masonry and plaster layers taken as thickness divided by design conductivity. What is left is the resistance the insulation alone must deliver, and thickness = R × λ. Use the declared thermal resistance from the Declaration of Performance rather than thickness divided by a rounded lambda: the declared figure is the one a building-control officer can trace to a U-value. The summing method itself is set out in EN ISO 6946. Design conductivity for rock wool external wall boards typically falls between 0.034 and 0.040 W/(m·K), and the value on the Declaration of Performance governs. Worked once, the numbers stop being abstract. For a target U-value of 0.30 W/(m²·K) on a 215 mm brick wall, the total resistance required is 3.33 m²·K/W; after the surface films and the masonry are removed, roughly 2.98 m²·K/W has to come from the board. At a rock wool design conductivity of 0.035 W/(m·K) that is about 104 mm. Published system calculations land in the same place: mineral wool at 0.036 W/(m·K) reaches 0.30 W/(m²·K) at 110 mm on 215 mm brickwork and 120 mm on 200 mm dense blockwork, while a graphite EPS board at 0.032 W/(m·K) does it at 90 mm and 100 mm respectively. Rock wool needs perhaps 20–30 mm more than EPS for the same U-value, and that is the entire thickness penalty — a detail, not a disqualifier. Glass wool sits in the same band and is chosen on the same arithmetic, with fire class and service temperature as the tiebreakers. Most conventional retrofit work settles between 90 and 120 mm. Deep retrofit and low-energy work runs 150–200 mm. The reason thickness dominates the result is simple arithmetic: moving from 100 mm to 200 mm adds about 3.15 m²·K/W to the assembly, which is more resistance than most solid masonry walls contribute in total. Insulation is the only lever in the build-up with that much range. Then the anchors claw some of it back. Every fixing that penetrates the insulation is a small thermal bridge, and the correction is explicit: Uc = U + χp × n, where n is the number of anchors per square metre and χp is the point thermal transmittance of one fixing. Where the anchor's own technical approval does not state a value, 0.004 W/K is taken for a galvanised steel screw with a plastic-covered head and 0.002 W/K for a stainless screw with a plastic cover or an air gap at the head. The correction only has to be carried when χp × n exceeds 0.04 W/(m²·K) — below that it is lost in rounding. Two consequences follow from that. The first is thermal: specifying stainless fixings, or fixings with an insulated cap, halves the point loss at no cost to holding power. The second is visual, and it is the one that generates complaints. Fastener points run marginally colder than the surrounding render, so they attract moisture and airborne dust and print themselves on the facade as a faint regular grid — the "leopard" or tile-ghosting pattern. The fix is the same in both cases: recessed anchors with an insulating cap, and no more anchors than the wind calculation actually requires. Every extra fixing is another thermal bridge, which is the whole argument for calculating the number instead of guessing it. Linear thermal bridges matter more than the point ones. A balcony slab punching through the insulation layer, a window reveal left uninsulated, or a base detail where the insulation layer is interrupted will each drop the local internal surface temperature below the dew point of the room air, and that is where condensation forms and mould appears. External wall insulation is uniquely good at suppressing these because it wraps the structure instead of sitting inside it — but only if the wrap is continuous. A thermal bridge that survives a retrofit is almost always geometric — a slab, a reveal or a base detail — not a material one. 3. Board Bonding and Anchoring Substrate preparation and primer European standards are strict: substrate flatness deviation ≤ 3 mm/m, verticality ≤ 2 mm/2 m — tighter than the ≤ 5 mm/m commonly required elsewhere. The sequence: high-pressure washing (≥ 6 MPa) to remove dust and oil; a silane-coupling / nano-silica primer forming Si–O–Si covalent bonds; and cementitious levelling (≤ 15 mm per layer, ≥ 24 h between coats). Primer thickness is 0.8–1.2 mm, applied at ≥ 5 °C and ≤ 85% RH; cold-climate epoxy-modified primers allow work down to −35 °C. Bonding sequence: anchor-first, then bond European practice reverses the usual order — anchor first, then bond. Steps: pre-drill with hole depth 10 mm beyond the effective anchor depth; select anchors by substrate (concrete pull-out ≥ 0.6 MPa, masonry ≥ 0.3 MPa); drive discs flush or 1–2 mm recessed to avoid finish cracking; apply adhesive by the strip-and-dab method (50–80 mm perimeter bead plus 8–10 dabs ≈ 100 mm); require tensile bond ≥ 0.60 MPa (wet) and ≥ 0.40 MPa (water-aged). Effective bonded area must be ≥ 50%. Anchor count is calculated from building height and wind load: 6–8 /m² generally, densified to 8–10 /m² at the ground floor, corners and openings. Embedment: ≥ 30 mm in concrete, ≥ 50 mm in masonry. Base coat and mesh embedding Base coat thickness is typically 5–7 mm (tolerance ≤ 3 mm/m). Apply 3–5 mm first, embedding alkali-resistant glass-fibre mesh (≥ 160 g/m²) while wet with ≥ 100 mm overlaps; once initial set, apply a second 2–3 mm pass. European standards specify 45° diagonal mesh overlaps to improve crack resistance — and never allow dry-laid mesh, which creates stress concentrations. 4. Critical Detailing at Special Locations Opening fire-stop borders ETAG 004 requires a fire-stop border ≥ 100 mm wide around every door and window. Method: pre-embed A-class rock wool strips of the same thickness; fit ≥ 100 mm stainless or galvanised metal edge profiles (≥ 0.8 mm, anchored ≤ 300 mm); seal with weather-resistant silicone (≥ 50% movement, 12–15 mm wide, ≥ 5 mm deep, passing EN 1609); and add 300×400 mm diagonal mesh reinforcements at corners. Anchors around openings are densified to ≤ 300 mm spacing with at least 3 per side. Internal/external corners with metal beads European standards mandate rigid metal corner beads — not the mesh-only reinforcement common elsewhere. Beads are hot-dip galvanised steel (≥ 1.2 mm), aluminium (6063-T5, ≥ 10 µm oxide) or stainless (304, ≥ 0.8 mm), fixed before the base coat (vertical ≤ 400 mm, horizontal ≤ 600 mm). At external corners, double mesh (≥ 400 mm total) wraps the bead. Movement and expansion joints A three-layer system is standard: breathable waterproof membrane + silicone foam rod + weather-resistant sealant. The membrane laps ≥ 150 mm; the foam rod rebounds ≥ 80%; the sealant recovers ≥ 90% and moves ≥ 50%. Expansion joints are set every 6–8 m or at structural breaks, 10 mm wide, filled with elastic polyurethane foam (≤ 10% compression set) and capped with a metal cover. 5. Horizontal Fire Barriers: The Band That Stops Vertical Spread Where a facade uses a combustible board, a horizontal fire barrier is the detail that decides whether a room fire becomes a building fire. It is a continuous band of non-combustible insulation, set at floor level, that interrupts the fuel path so flame cannot run up the elevation. The geometry that recurs across codes is consistent: the band is at least 300 mm high, it sits at slab level, it is the same thickness as the main insulation — never thinned to save material — and it must be continuous across the whole elevation, including across openings and around corners. Where the roof meets the wall, the band is deepened to 500 mm, because that junction collects heat and is the hardest place to fight a fire from. At window heads the band is carried 300 mm beyond each side of the opening, not just across its width. Two execution rules separate a real barrier from a decorative one. The first is bonding. Normal boards are bonded over 40–50 % of their area; a fire barrier is bonded over 100 %. Any unbonded pocket behind the band is a void flame can travel through, which defeats the entire purpose. The second is sequencing: the barrier is installed simultaneously with the surrounding insulation. Leaving a 300 mm gap and returning to fill it later — a common site shortcut — produces a band that is not connected to anything, and it is the defect most often found at inspection. Material choice inside the band favours lamella boards — rock wool strips cut so the fibres run perpendicular to the wall. The tensile strength perpendicular to the face of a lamella board is an order of magnitude higher than that of a standard board (≥ 100 kPa against ≥ 10 kPa in typical European specifications), and because the band is fully bonded and carries its own weight plus the render, that margin is what keeps it on the wall. Mechanically, the band is supplemented with anchors that clamp the lower mesh layer, spaced no more than 600 mm apart, at least one per board, and with a plate diameter of at least 100 mm when lamella is used. A support bracket under the band is worth specifying: it prevents long-term sag in a strip that is fully bonded and heavy. How much does a 300 mm band actually buy? Window-fire tests put flame spread rates on a combustible facade above 2 m/s, and without a barrier flame can reach the floor above in roughly two minutes. A correctly installed non-combustible band holds that spread for two to three minutes. That is not a small number — it is the difference between an evacuation and a rescue. Where the whole facade is already non-combustible — a full rock wool board build-up classified to A1 — the barrier question changes. An all-A1 external wall insulation system does not need discrete bands because there is no continuous fuel to interrupt. This is the argument for mineral wool over EPS on tall buildings, and it is worth making explicitly in a specification rather than leaving it implicit. One honest caveat from European test work: when a mineral wool band is inserted into an EPS system, the EPS-to-wool joint retains roughly half the bond strength of the polystyrene itself. Full hygrothermal cycling to ETAG 004 produced no visible cracking or debonding at those junctions across the finishes tested, so the detail is sound — but the joint is the weak link, and it is where mesh reinforcement and bonding discipline matter most. 6. Wind Load and Anchor Calculation Wind load is zoned, not uniform, and anchor counts quoted as "6 to 8 per square metre" are rules of thumb. The real number comes out of a wind calculation, and the calculation usually surprises people in one direction only: the corners and the parapet need far more than the middle of the wall. The system's wind resistance is assembled from the fixings: Rd = (Rpanel × npanel + Rjoint × njoint) / γ where Rpanel and Rjoint are the characteristic resistances of anchors placed away from and on board joints, n is the number of each per square metre, and γ is the national safety factor. The critical subtlety is that pull-through often governs, not pull-out. A fixing may hold perfectly well in the concrete and still fail by dragging its plate through the insulation board. Characteristic pull-through for a 60 mm plate in 60 mm of board is around 530 N; fitting a 140 mm extension washer roughly doubles that to 1,000 N. With a partial material factor of 2.5, the design value per anchor becomes about 0.40 kN. Run that per board and the zoning becomes obvious. Five anchors on a 1.2 × 0.6 m board gives 2.0 kN, or 2.77 kN/m² — comfortably above the design wind suction of about 1.8 kN/m² that governs the main wall zones. The same five anchors are not enough at the parapet, where six per board are needed to reach 3.33 kN/m² against a local demand of 2.85 kN/m². Measured retrofit projects land on the same split: 8 anchors/m² in the edge zone, 6 anchors/m² in the central zones. Adhesive is not a spectator in this calculation. A 40 % bonded system at the ETAG 004 minimum bond strength of 0.08 N/mm² carries an unfactored wind capacity of roughly 2.37 kN/m² — adequate for the main zones, short of the parapet. Where the bond alone cannot carry the local load, either the bonded area is increased or supplementary anchors are designed to take the remainder. Bond strength itself is verified on site by five pull-off tests, none of which may fall below 0.08 N/mm², with the dolly bonded after the adhesive has cured for one day per millimetre of render thickness. Two practical notes. Board tensile strength perpendicular to the face sets the anchor's pull-through capacity, so a low-strength board cannot be rescued by adding more anchors of the same plate size — increase the plate diameter instead. And the certified envelope has a ceiling: ETICS approvals generally top out at a characteristic wind load of −2.2 kN/m². Beyond that, the system as a whole is out of its field of application, and no amount of extra fixings changes that. For general reference on wind actions, see EN 1991-1-4; the ETICS-specific assessment route remains ETAG 004 and its successor EAD. The same load-first logic governs industrial insulation specifications, where mechanical rather than wind loads set the fixing pattern. 7. Quality Control and Common Defects - Delamination / detachment — Europe uses infrared thermography + drone scanning (per EN 13187, ≥ 320×240 px, ≤ 50 mK sensitivity); voids show ≥ 2 °C (day) or ≥ 1 °C (night) contrast. Prevention: thorough substrate prep, adequate bonded area, correct embedment (≥ 25 mm concrete / ≥ 50 mm masonry). - Surface cracks — the rule is thin, layered application (≤ 5 mm per pass), ≥ 100 mm 45° mesh overlaps, ≥ 7 days curing, and no work below 5 °C. - Water ingress — joints packed with rock wool strips (density ≥ board) or closed to ≤ 1.5 mm; continuous sealant at deformable joints and sills; drip lines or ≥ 5% slopes at plinths, sills and soffits; membrane laps ≥ 150 mm fixed ≥ 3 points/m². - Fire safety — material must reach EN 13501 A1/A2 (non-combustible); fire-stop borders ≥ 100 mm; fire barriers ≥ 300×300 mm for buildings above 22 m; anchors with ≥ 30 mm embedment and ≥ 0.3 kN tension capacity. 8. European Installation Tips - Bond control — combine strip bonding (≥ 50 mm continuous beads) with point anchoring (disc ≥ 60 mm); adhesive thickness 3–5 mm; coverage ≥ 50%. - Anchor timing — install anchors at least 24 h after bonding so adhesive fully cures; never over-drive (cracks the board); discs flush or 1–2 mm recessed. - Mesh work — two-pass base coat (3–5 mm + 2–3 mm = 5–7 mm); mesh flat, no wrinkles, ≥ 100 mm overlaps, embedded wet; double mesh at external corners with the metal bead between layers. - Winter methods — keep ≥ 5 °C for 24 h post-application; cold-climate primers to −35 °C; electric-blanket curing (around 40 °C, 48 h); mobile heated enclosures (double PVC + 50 mm rock wool core) to block moisture. 9. Trends Shaping the System European rock wool ETICS is moving toward systematised, standardised design (EN 17237 "kits", strict weathering/wind/impact/freeze-thaw testing, BIM-driven simulation), sustainability (detachable systems, low-carbon rock wool, circular reuse) and smart, multi-functional facades (embedded sensors for temperature, humidity and cracks; integrated thermal-water-acoustic performance; aesthetic diversity). 10. Rock Wool vs EPS and PU: What Changes in a Fire Insulation choice on a facade is a fire-strategy decision long before it is a thermal one. Three materials are most often compared, and they behave completely differently once flame is present: | Rock wool | EPS (expanded polystyrene) | PU / PIR | Reaction to fire (EN 13501-1) | A1 — non-combustible | E as standard; B/C with flame-retardant grades | B/C with facings | Behaviour in fire | No fuel contribution; holds shape | Softens near 100 °C, melts, drips, spreads flame | Chars and smoulders | Smoke | Negligible | Dense | Dense, high CO and HCN | Declared conductivity | 0.034–0.040 W/(m·K) | 0.030–0.040 W/(m·K) | 0.022–0.028 W/(m·K) | Practical service limit | Well above 250 °C | Around 70–80 °C | Around 100–120 °C | The practical consequence is vertical fire spread. A combustible board inside a ventilated cavity gives flame a continuous path up the facade. A non-combustible rock wool board does not — which is why height-based rules in most European codes require non-combustible insulation above a defined building height, and why fire-stop borders are cut from rock wool strips rather than offcuts of the main board. Rock wool is not the only mineral wool that reaches A1. Glass wool also carries an A1 non-combustible classification, and the two are regularly offered against each other on the same facade. The reaction-to-fire class is identical; the service ceiling is not, and that is usually what actually decides between them. Smoke decides the escape calculation. Rock wool contributes essentially nothing to fire load or smoke toxicity; EPS and PU both add substantial calorific value, and burning PU releases carbon monoxide and hydrogen cyanide. For escape routes, stair cores and high-occupancy facades, that difference matters far more than a few millimetres of extra thickness. On a facade the service ceiling is never approached, but specifiers still ask where it sits, because the same material family also runs on industrial equipment. Binder behaviour and the upper service range are set out in what temperature rock wool can withstand. 11. Fire Walls and Curtain Walls: Boards with Steel Furring The same board behaves differently once it moves from a rendered facade into a framed assembly. Two build-ups cover most projects. Fire and partition walls with light steel furring. The sequence is structural substrate → light-steel C-studs (typically 50–100 mm) → rock wool board friction-fit between the studs → board facing on one or both faces. Because the board is held by friction and stud spacing rather than adhesive, density matters more here than on a bonded facade: 80–150 kg/m³ is the usual range, chosen for the combination of fire resistance, acoustic absorption and dimensional stability. Specified correctly, this assembly contributes to fire-resistance ratings from one to four hours depending on the number and type of facing boards. Read the rating from a tested assembly, never from an insulation datasheet — the number belongs to the build-up, not the board. Curtain wall spandrels and shadow boxes. In a ventilated or unitised curtain wall, the risk is fire travelling up the cavity from one floor to the next. The standard detail is a fire stop at every slab edge: rock wool board ≥ 100 mm high, backed by a galvanised steel sheet, closing the gap between the slab and the rear of the cladding panel. Combined with the ≥ 100 mm opening borders described earlier, this turns a continuous cavity into a series of compartments. Where one layer has to deliver both acoustic and fire performance — plant rooms, stair cores, party walls — rock wool acoustic panels suit flat, framed builds, while rock wool blanket handles irregular geometry and services penetrations. 12. Moisture, Condensation and Service Life External wall insulation is, before anything else, a condensation-control strategy. Putting the insulation outside the structure keeps the masonry close to indoor temperature, which pushes the dew point out of the wall and into the insulation or the base coat. Interstitial condensation inside the structure therefore stops being a concern — and where any condensate forms at all, it forms near the outer surface where it can dry outward in warm weather. With the wall warm, condensation risk is governed by the vapour path, and the rule is directional: diffusion resistance must decrease from inside to outside. An inner layer may retard vapour more than the outer layers, but never the reverse — otherwise vapour that gets in cannot get back out. Rock wool helps here because it is vapour-open, with a water-vapour resistance factor μ of roughly 1–2, against values an order of magnitude higher for closed-cell foams. Moisture leaving the masonry passes through the board and dries instead of accumulating. That property is why mineral wool is the default on solid masonry and historic fabric that has to keep releasing stored moisture, and it is why the finish has to stay vapour-open too: a silicate or siloxane render preserves the advantage, while a vapour-tight coating throws it away. Assessment runs on two levels. The Glaser steady-state method, given in EN ISO 13788, is enough for simple build-ups; it is explicitly a simplification and reaches its limits with hygroscopic materials, capillary transport and driving rain, where a dynamic hygrothermal simulation to EN 15026 is the honest answer. A thermal bridge cold enough to pull the surface below dew point will produce local condensation however good the board is. It is also worth stating where external wall insulation does not win. In hot-humid climates the vapour-openness that helps in temperate Europe becomes a liability: published hygrothermal studies of rock wool ETICS in humid subtropical regions find genuine interstitial condensation risk at the inner layers, and the recommended control is a vapour retarder with a sufficiently high sd value rather than more insulation. Diffusion-open is a strategy, not a virtue, and it has to be checked against the climate. On service life, the European assumption for a rendered ETICS under normal maintenance is at least 25 years. Two qualifications matter. First, durability assessment under ETAG 004 / EAD 040083-00-0404 covers hygrothermal cycling only — heat–rain and heat–cold cycles — and does not address UV radiation, atmospheric pollution or biological colonisation, all of which act on real facades. Second, the anomaly record is long: cracking, detachment of the finishing coat, loss of adhesion between layers, colour change, runoff staining, efflorescence, biological growth and flatness defects. Most of them trace back to water. Long-term field evidence is genuinely reassuring — retrofits twenty years old have been found still performing thermally and mechanically — but twelve-year natural-exposure surveys still record three persistent defect families: surface defects, cracks and local deterioration. Low water absorption correlates with long service life, which is why the absorption limits in the system approval are worth enforcing rather than treating as paperwork. The maintenance consequence is unglamorous and effective: keep water out, and inspect the places water enters. Sealant at movement joints and sills, drip details at plinths and soffits, membrane laps, and the condition of the finish coat are what determine whether the system reaches its assumed life. See green building insulation practice for how facade upgrades are sequenced alongside other envelope measures. 13. Fire Inspection and Acceptance: What Inspectors Check Most facade fire failures are documentation and detailing failures, not material failures. A submission that clears review on the first pass usually has these in order: - Classification evidence — a current EN 13501-1 report showing A1, issued for the product actually delivered rather than a generic family certificate. - Declaration of Performance and ETA — traceable to the batch, with declared thermal conductivity, tensile bond and reaction-to-fire values matching the specification. - Thickness and density as built — verified against the approved drawings, not the quotation. - Fire-stop continuity — ≥ 100 mm borders around every opening, plus a fire barrier band at every slab edge in curtain wall build-ups. This is the single most common rejection. - Anchor evidence — pull-out test records (≥ 0.3 kN), embedment ≥ 30 mm in concrete or ≥ 50 mm in masonry, and the densified pattern at corners and openings. - Bonded area — ≥ 50 % verified, with photographic or pull-off records at the agreed frequency. - Infrared survey — thermography to EN 13187 with agreed void acceptance criteria, carried out after curing and before handover. Two defects cause disproportionate rework because the finish hides them: dry-laid mesh, which leaves the reinforcement outside the base coat, and substituted insulation class, where a combustible board is swapped into a non-combustible specification. Both are cheap to catch at inspection stage and expensive to rectify once the finish coat is on. 14. Conclusion European rock wool facade systems excel through systematic design (whole-system performance, not single-material), refined execution (anchor spacing, mesh direction, coat thickness), scientific acceptance (infrared inspection, documented ETA and pull-out records) and environmental progress (detachable, low-carbon, circular). Specifying rock wool external wall insulation to ETAG 004 / EN 13500 discipline — anchor-first sequencing, ≥ 50% bonded area, correct fire-stop and metal-bead detailing, non-combustible material throughout, and infrared quality control — raises facade reliability and fire safety for any project. Related Reading - Rock Wool Facade Insulation for Buildings - Green Building Insulation Solutions - Non-Combustible Insulation Systems: A1 Fire Rating Explained - Industrial Pipe Insulation Materials: The Complete Guide Related products: rock Wool Strips, Rockwool Insulation Slabs — Rock Wool Board, rock Wool Acoustic Panels Related applications: Building FAQ: Q: Which European standards govern rock wool external wall insulation? A: ETAG 004 is the certification core for rendered ETICS, EN 13500 sets performance requirements for mineral-wool systems, and EN 17237 (published 2022) covers ETICS kits with rendered finishes. Reaction to fire is classified to EN 13501-1, and thermographic inspection follows EN 13187. Q: How thick should rock wool external wall insulation be? A: Work backwards from the target U-value rather than picking a thickness off a product sheet. Convert the target to a total resistance (R = 1 / U), subtract the inner and outer surface resistances of 0.13 and 0.04 m²·K/W and the resistance of the existing wall, then multiply what is left by the board's design conductivity. For a 0.30 W/(m²·K) target that puts mineral wool at roughly 110 mm on 215 mm brickwork and 120 mm on dense blockwork. Most retrofit work lands between 90 and 120 mm; deep retrofit runs 150–200 mm. Q: What adhesive coverage is required for rock wool boards? A: Effective bonded area must be at least 50%, achieved with the strip-and-dab method: a 50–80 mm perimeter bead plus 8–10 dabs of roughly 100 mm. Tensile bond strength should reach at least 0.60 MPa wet and 0.40 MPa after water ageing, with anchors added at 6–10 per square metre depending on height and wind load. Q: How many anchors does a rock wool facade need per square metre? A: Whatever the wind calculation returns. System resistance is Rd = (Rpanel × npanel + Rjoint × njoint) / γ, and pull-through through the board often governs before pull-out from the substrate: a 60 mm plate in 60 mm of board carries roughly 530 N characteristic, roughly doubled by a 140 mm extension washer. In practice that means about 6 anchors/m² over the main wall and 8 anchors/m² in edge and parapet zones, with each fixing also counted as a small thermal bridge in the U-value. Q: How wide must the fire-stop border be around openings? A: ETAG 004 requires a fire-stop border at least 100 mm wide around every door and window. It is formed from non-combustible rock wool strips of the same thickness as the main board, protected by a metal edge profile at least 0.8 mm thick and sealed with weather-resistant silicone. Q: What is a horizontal fire barrier and when is one required? A: A continuous band of non-combustible insulation at least 300 mm high, set at slab level and the same thickness as the main insulation, which interrupts the fuel path in a combustible facade. It is bonded over 100 % of its area rather than the 40–50 % used for normal boards, and it must be installed at the same time as the surrounding insulation — leaving a gap to fill later is the most common defect. Where the whole facade reaches A1, no discrete bands are needed because there is no continuous fuel to interrupt. Q: Is rock wool safer than EPS or PU on a facade? A: Yes, for fire. Rock wool is classified A1 non-combustible to EN 13501-1: it contributes no fuel, no meaningful smoke, and holds shape well above 250 °C. EPS softens near 100 °C, melts and drips, and spreads flame. PU chars and smoulders and releases carbon monoxide and hydrogen cyanide. On tall buildings and escape routes that difference usually decides the specification. Q: What density rock wool board is used in fire walls with steel furring? A: Boards friction-fit between light-steel C-studs are typically specified at 80–150 kg/m³, selected for the combination of fire resistance, acoustic absorption and dimensional stability. The fire-resistance rating applies to the complete tested assembly — studs, board and facings — so it must be read from an assembly test report rather than a product datasheet. Q: How is vertical fire spread stopped in a curtain wall? A: By compartmenting the cavity at every slab edge. The standard detail is rock wool board at least 100 mm high, backed by a galvanised steel sheet, closing the gap between the floor slab and the rear face of the cladding panel. Combined with 100 mm fire-stop borders around openings, this prevents flame travelling up the cavity between floors. Q: Can external wall insulation cause condensation? A: Installed correctly it prevents it. Placing the insulation outside the structure keeps the masonry close to indoor temperature, so the dew point moves out of the wall and into the insulation or the base coat. The vapour path still has to run in the right direction — diffusion resistance must fall from inside to outside — and the finish has to stay vapour-open. In hot-humid climates a rock wool system can still show interstitial condensation risk, and the control there is a vapour retarder with a high enough sd value rather than more insulation. Q: What do inspectors check before accepting a rock wool facade? A: A current EN 13501-1 A1 certificate matching the delivered product, a batch-traceable Declaration of Performance and ETA, as-built thickness and density against the approved drawings, fire-stop continuity, anchor pull-out records of at least 0.3 kN, verified bonded area of at least 50%, and an infrared thermography survey to EN 13187 before handover. Q: Can rock wool ETICS be installed in winter? A: Yes, with controls. The substrate and ambient temperature must stay at or above 5 °C for 24 hours after application. Cold-climate epoxy-modified primers allow work down to −35 °C, electric-blanket curing at around 40 °C for 48 hours is used on small areas, and mobile heated enclosures with a double PVC skin and 50 mm rock wool core protect larger sections from moisture. Q: How are delamination and voids detected after installation? A: Infrared thermography, typically drone-mounted, to EN 13187 — at least 320×240 pixel resolution and 50 mK sensitivity. Voids and debonded areas show a surface temperature contrast of at least 2 °C in daytime surveys or 1 °C at night. Prevention is better: thorough substrate preparation, bonded area above 50%, and correct anchor embedment. Q: What causes facade insulation to fail fire inspection most often? A: Two defects dominate. Fire-stop discontinuity, usually a missing or undersized border around openings or at curtain-wall slab edges. And substituted insulation class, where a combustible board is swapped into a non-combustible specification. Both are hidden by the finish coat, so both must be checked at inspection stage rather than after completion. Q: How long does a rock wool ETICS last? A: European guidance assumes at least 25 years under normal maintenance. Two caveats apply. The durability assessment covers hygrothermal cycling only and does not address UV radiation, atmospheric pollution or biological growth, and the recorded defect list — cracking, finish detachment, loss of adhesion between layers, staining, biological colonisation — traces back to water in most cases. Keeping sealant joints, drip details and the finish coat in good order is what actually delivers the assumed life. ### Ceramic Fiber vs Rock Wool for Furnace Linings: Which to Choose URL: https://www.rosetexwool.net/news/ceramic-fiber-vs-rock-wool-furnace/ 2026-08-13 | Author: Rosetexwool Editorial | Category: industry insight Summary: A data-backed comparison of ceramic fiber and rock wool for industrial furnace linings — temperature limits, thermal conductivity, installation, lifecycle cost, and health impact. Ceramic Fiber vs Rock Wool for Furnace Linings: Which to Choose Choosing the right heat-resistant material for furnace linings determines a furnace's thermal efficiency, operating safety, and total cost of ownership. This comparison focuses on the two materials that cover most industrial duty; the full temperature-tier ranking is in our 2026 materials guide. Two materials dominate industrial furnace insulation — ceramic fiber and rock wool (stone wool). Both are non-combustible and widely specified, yet their chemistry, temperature tolerance, and lifecycle economics differ sharply. This guide compares the two materials across composition, temperature limits, thermal conductivity, installation, maintenance, cost, and health impact — and gives you a decision checklist you can apply to your own lining project. Material Basics: Composition & Structure Property | Ceramic Fiber | Rock Wool | Main chemistry | Al₂O₃ (42–55%) + SiO₂, optional ZrO₂ (up to 15%) | Basalt / slag (SiO₂, Al₂O₃, CaO, MgO) | Form | Spun or blown amorphous alumino-silicate (or zirconia) fibers | Centrifuged volcanic-rock or slag fibers | Melt temperature | 1800–2000°C | 1400–1500°C | Ceramic fiber is an engineered refractory material; rock wool is a mineral wool made from abundant igneous rock. That difference drives everything below. Temperature Limits: The Decisive Difference Temperature is the single most important selection factor. Property | Ceramic Fiber | Rock Wool | Continuous service temp | 1000–1260°C (standard); 1250–1350°C (zirconia); up to 1600°C+ (special) | ≤ 650°C (degrades above; melts ~1000°C) | High-temp stability | Almost no shrinkage, stable structure | Structure collapses above ~650°C | Typical hot-face use | Ethylene cracker furnaces to 1400°C | Outer-shell / cold-face backup only | Our ceramic fiber bulk is rated for continuous use up to 1430°C, making it the correct choice for furnace hot faces, combustion chambers, and high-temperature ducting. Rock wool blanket carries an A1 non-combustible rating and excels as back-up / cold-face insulation and for furnaces operating below 650°C. Rule of thumb: if operating temperature exceeds ~650–750°C, ceramic fiber is the only safe choice of the two. Thermal Conductivity & Energy Efficiency A common misconception is that ceramic fiber is the "better insulator" at every temperature. The data says otherwise: - At 500°C, ceramic fiber conductivity is 0.11–0.15 W/m·K, while rock wool is 0.035–0.045 W/m·K — rock wool is actually more efficient in the low-to-mid range. - Ceramic fiber's real energy advantage comes from its very low thermal mass: furnaces heat up and cool down faster, and in high-temperature service ceramic fiber linings improve thermal efficiency by 15–20% versus heavier systems. So the two materials win in different bands: rock wool for low-temperature conductivity, ceramic fiber for high-temperature survival plus faster thermal cycling. In practice, a petrochemical furnace lining often pairs a ceramic fiber hot face with rock wool behind it. Density, Thermal Shock & Water Resistance - Density: ceramic fiber 64–450 kg/m³; rock wool 40–200 kg/m³. High-density (zirconia) ceramic fiber serves extreme heat; low-density rock wool suits mid-low temp. - Thermal shock: ceramic fiber resists rapid temperature swings far better — its low expansion and fiber toughening prevent cracking. This is why it is preferred for furnaces that start and stop frequently. - Water: rock wool is naturally hydrophobic; ceramic fiber absorbs more water but can be treated to ~99% water repellency. In damp or wash-down environments, rock wool has the edge. Installation & Maintenance Ceramic fiber ships as pre-compressed modules anchored directly to the furnace shell with studs — no curing required, and modular design cuts downtime during retrofits. Rock wool usually needs multi-layer wrapping or special anchoring, takes longer to install, and its coarser fibers demand more handling protection. Maintenance tells the lifecycle story: - Ceramic fiber linings last 5–10 years with preventive care (e.g., a high-temperature hardener sprayed every 12 months). - In high-temperature service, rock wool can fail in under 3 years as its structure collapses. One ethylene-cracker case saw heat loss drop from 550 W/m² to 300 W/m² after switching to ceramic fiber modules — about 200,000 kWh/year saved. Life-Cycle Cost: Why Ceramic Fiber Often Wins Although ceramic fiber costs 20–30% more upfront, its lower thermal mass and longer life usually make it cheaper over the asset's life: - Energy: 15–20% efficiency gain in high-temperature furnaces. - Payback: 1.2–1.8 years on typical petrochemical projects — far shorter than the 10–15-year equipment life. - Composite design: a "hot-face ceramic fiber + cold-face rock wool" wall captures ceramic fiber's heat resistance and rock wool's cost efficiency in one lining. Environmental & Health Considerations - Carbon: ceramic fiber ~0.03 tCO₂/t vs rock wool ~0.034 tCO₂/t — close, with rock wool's higher recycling rate (e.g., EU Rockcycle at 95% re-melt) giving it a circularity edge. - Health: ceramic fiber is classified by IARC as Group 2B (possibly carcinogenic) with residual crystalline silica ≤1%; it requires respirators, gloves, and protective clothing during cutting or gunning. Rock wool's coarser fibers are lower in biopersistence and generally need only basic dust control. Both demand PPE, but ceramic fiber's bar is higher. Which Should You Choose? (Decision Checklist) - Operating > 1200°C? → Ceramic fiber, preferably zirconia grade. - 600–1200°C, energy-critical or frequent cycling? → Ceramic fiber. - 600–1200°C, stable load & tight budget? → Rock wool can work, but watch the shorter service life. - < 600°C? → Rock wool — better conductivity, cheaper, naturally hydrophobic. - Large furnace? → Composite: ceramic fiber hot face + rock wool cold face. Most petrochemical and process furnace linings run hot enough that ceramic fiber — module or bulk form — is specified for the working lining, with rock wool or calcium silicate behind it. For a deeper look at hot-face vs backup selection across furnace types, see Alumina & AES furnace lining zones. Related Reading - Petrochemical Reformer Furnace Reline Case Study - Rock Wool for Marine & Offshore Applications Review our iron and steel industry insulation applications for furnaces, kilns, and continuous-casting lines in steel and iron production. Related products: Ceramic Fiber Modules, Ceramic Fiber Plus Blanket, Refractory Ceramic Fiber Blanket — Ceramic Fiber Blanket Insulation, Refractory Ceramic Fiber Board for High Temperature Insulation Related applications: Iron & Steel, Petrochemical FAQ: Q: Can rock wool be used inside a furnace? A: Only if the continuous operating temperature stays below about 650°C. Above that, rock wool loses strength and eventually melts near 1000°C. For hot-face furnace lining, ceramic fiber is required. Q: Is ceramic fiber better than rock wool? A: Not in every case. Ceramic fiber wins above roughly 650–750°C and where thermal shock or low weight matter; rock wool wins on cost, rigidity, and low-temperature conductivity below 600°C. They are complementary, not strictly competing. Q: What temperature can ceramic fiber withstand? A: Standard grades serve 1000–1260°C continuously; zirconia grades 1250–1350°C, with special types rated to 1600°C and beyond. Its low thermal mass also improves furnace energy efficiency by 15–20%. ### Ceramic Fiber Raw Materials and Manufacturing Process: A Technical Study URL: https://www.rosetexwool.net/news/ceramic-fiber-raw-materials-manufacturing-process/ 2026-08-12 | Author: Rosetexwool Editorial | Category: industry insight Summary: A technical study of ceramic fiber raw materials — alumina, silica, zirconia — and the melt-spinning, blowing and sol-gel processes, plus performance drivers, applications and market outlook. Introduction Ceramic fiber is a high-performance industrial insulation material prized for its light weight, high strength, temperature resistance, low thermal conductivity and chemical stability. Often called the "fifth form of energy," it is central to industrial energy savings. This article examines the raw-material chemistry, the main manufacturing routes, how composition and process drive performance, and the market outlook. 1. Raw Material Composition and Chemistry Base oxide system Ceramic fiber is built on alumina (Al₂O₃) and silica (SiO₂); the grade is set by composition: Grade | Composition | Continuous use (°C) | Max (°C) | Standard (low-alumina) | Al₂O₃ 43% / SiO₂ 55% | 1000 | 1200 | Standard | Al₂O₃ 45% / SiO₂ 52% | 1100 | 1300 | High-alumina | Al₂O₃ 35% / SiO₂ 46.7% | 1250 | 1400 | Zirconia-containing | Al₂O₃ 40% / SiO₂ 58% / ZrO₂ 15–17% | 1350 | 1600 | High-purity | Al₂O₃ 72% / SiO₂ 28% | 1500 | 2000 | - Al₂O₃ — the dominant component. Above 70% the crystal phase shifts from amorphous to mullite, lifting continuous-use temperature by 200–400°C. High-purity fiber (Al₂O₃ ≥72%) runs stably above 1500°C, up to a 2000°C peak. - SiO₂ — network former with Al₂O₃. Over 55% lowers temperature resistance but improves flexibility and tensile strength. - Stabilizers — ZrO₂ (15–17% in zirconia grades) and Cr₂O₃ (1.8% in high-purity) suppress high-temperature crystal transformation and delay embrittlement; zirconia grades last 200%+ longer under 1200–1400°C thermal shock. Source and purity - Natural minerals: kaolin (Al₂O₃ 46–48%, SiO₂ 52–54%), silica powder (SiO₂ >98%), feldspar — lower cost but more impurities (Fe₂O₃, Na₂O, K₂O form a low-melting glass phase). - Synthetic: high-purity Al₂O₃ (>99%), SiO₂ (>99.9%) — costly; raw material is 35–40% of production cost for high-purity fiber. - Purity: industrial grades require Al₂O₃+SiO₂ ≥95% and total impurities ≤5%; aerospace grades require ≥99% and <0.5%. Additives and modifiers - Anti-caking agents (B₂O₃, borax) 0.5–1.2% - Binders (silicone, phenolic resin) 1–3% - Wetting agents (silicone oil, PTFE emulsion) 0.5–1.5% - Surface modifiers (rare-earth oxides Y₂O₃, La₂O₃) raise interfacial strength 30–50% in composites 2. Manufacturing Processes Melt spinning (dominant for industrial grades) - Centrifugal spinning — raw materials melted at 1600–1800°C, spun at 1850–2200 m/min into 3.0–5.0 μm fibers; shot (>212 μm) held ≤12%. Output 5000–6000 t/line/year (2–4× blowing), tensile 120–180 MPa, thermal conductivity ~0.12 W/m·K at 400°C (1260°C grade). Coarse, long fibers give strong erosion and impact resistance — ideal for modules. - High-pressure blowing — melt at 1700–1900°C blown at 0.5–0.8 MPa into 2.0–3.0 μm fibers. Finer, lower conductivity (0.08 W/m·K at 400°C) and better thermal-shock stability, but weaker erosion resistance. Sol-gel process (high-purity, aerospace) Metal alkoxide sol → spinneret → gel fiber in inert atmosphere → heat treatment (dry <200°C, decompose 200–700°C, sinter 1150–1350°C) → high-purity alumina fiber. Achieves Al₂O₃ >99%, impurities <0.5%, continuous use above 1600°C, viscosity 5–20 Pa·s. Energy use is 3–5× melt spinning; cost ~USD 15,000–17,000/t versus 5,000–15,000 for standard alumino-silicate. Other advanced routes Electrospinning makes nanofibers <100 nm (porosity 276.1 m²/g) but is not yet industrial; freeze-drying, CVD (e.g., SiC fibers) and hydrothermal routes serve aerospace and R&D. Process parameters vs performance Best melt temperature is 1700–1850°C for alumino-silicate and 1800–1950°C for zirconia grades; centrifugal line speed 1850–2200 m/min, blowing pressure 0.5–0.8 MPa; sintering at 1150–1350°C sets crystallinity. Modern solvent recovery reaches 99.5%. 3. How Composition and Process Drive Performance - Temperature resistance — each +10% Al₂O₃ raises continuous-use temperature ~150–200°C (standard 43% → 1000°C; high-purity 72% → 1500°C). ZrO₂ boosts thermal-shock life 200%+ at 1200–1400°C. Impurities (Fe₂O₃, alkali oxides) form a low-melting glass and must be limited. - Thermal conductivity — finer fiber means lower k: blown 2–3 μm at 0.08 W/m·K versus spun 3–5 μm at 0.12–0.16 W/m·K at 400°C (≈50% gap). Longer fiber and lower density also lower k. - Mechanical — coarse fibers (120–180 MPa) are stronger than fine (80–120 MPa); long fibers resist impact better; ~2% binder raises erosion resistance 40–50% with minimal insulation penalty. - Process — optimum melt 1700–1850°C for 30–45 min; sintering to 1350°C yields 50–80 nm grains (best strength and stability); inert atmosphere prevents surface oxidation. 4. Applications and Market Outlook Applications - Industrial kilns — linings (heat capacity 0.2–0.3 J/g·K, k 0.03–0.18 W/m·K), door seals (1000–1200°C) and high-temperature pipe sleeves (1000–1400°C). A national building-materials research institute reports kiln heat loss cut 15–20% and energy 8–12% with ceramic-fiber linings. - High-temperature filtration & environmental — filter tubes (276.1 m²/g, >1500°C flue gas) for steel and cement off-gas; dry desulfurization–denitration–dedusting units raise treatment efficiency 20–30% and cut footprint 30%. - New energy & high-end manufacturing — EV battery-pack insulation (demand +85% as NEV sales passed 10 million in 2024; ceramic fiber's new-energy share rose from 3% to 12% over 2020–2024); aerospace thermal protection and engine parts (silicon-carbide ceramic-matrix composites raise fuel efficiency ~15% and cut NOx ~50%); semiconductor near-zero-expansion composites. Market size - Global: ~USD 1.15–1.2 billion in 2024 (insulation ~65%, composites ~35%); projected USD 2.05–2.62 billion by 2030, CAGR 8.4–10.15% (per market research). - China: RMB 7.6 billion in 2024 (industrial ~60%, high-end composites ~40%); above RMB 9.8 billion by 2030, CAGR ~5.1%; high-end share expected to rise from 35% to 50%+ within five years. - Asia-Pacific: ~USD 0.97 billion in 2025 → USD 1.9 billion by 2035, CAGR 6.7%; China is over 65% of the regional total. Trends - Greener process — solvent recovery 99.5%; green-power and scrap-recycling routes cut carbon footprint ~23%; AI control lowers energy ~3.8%; closed crushing plus wet dedusting brings emissions below 15 mg/m³ (under the 30 mg/m³ limit). - Higher-end and functional — high-purity alumina (≥99%) and nanofibers (<100 nm); oxide–non-oxide (Al₂O₃+SiC) and intermetallic composites; rare-earth modifiers raise thermal-shock resistance 60–80%; catalytic, adsorptive and EMI-shielding fibers. - Policy and opportunity — energy-saving promotion catalogs with up to 15% capex subsidy; green-product certification with carbon-footprint tracking (an EU import rule expected by 2027); high-energy industries (steel, cement, glass) keep demand rising (steel energy intensity −5.2% in 2024, with ceramic-fiber lining contributing 18%). 5. Conclusion and Recommendations Al₂O₃ content is the core of temperature resistance, ZrO₂ stabilizers extend thermal-shock life, and impurity control secures long-term stability. Melt spinning (centrifugal and blowing) dominates industrial grades on cost and throughput, while sol-gel serves high-end applications at higher cost. For producers, the priorities are: tighten raw-material purity (especially alkali oxides); adopt closed-loop solvent recovery and smart manufacturing (target 99.5% recovery); develop high-purity, high-performance grades for aerospace and EV markets; expand composite applications; and pursue green certification for market access. By 2030 the global market is expected to reach USD 2.05–2.62 billion and China above RMB 9.8 billion, with CAGR above 5.1%. Related Reading - aerospace and defense insulation - nuclear power insulation - petrochemical insulation - steel furnace and ladle insulation - PCW module supplier qualification checklist For a dedicated manufacturer and supplier evaluation guide, see our refractory ceramic fiber manufacturer guide. Related products: Refractory Ceramic Fiber Blanket — Ceramic Fiber Blanket Insulation, Ceramic Fiber Cloth, Ceramic Fiber Modules, Ceramic Fiber Paper, Ceramic Fiber Plus Blanket Related applications: Cement, Iron & Steel, Building FAQ: Q: What is ceramic fiber made of? A: Primarily alumina (Al₂O₃) and silica (SiO₂), with stabilizers such as zirconia (ZrO₂) or chromia (Cr₂O₃) in high-temperature grades. Composition sets the temperature class: standard grades run at 1000–1100°C, high-alumina and zirconia grades at 1250–1350°C, and high-purity alumina fiber above 1500°C. Q: What is the difference between spun and blown ceramic fiber? A: Centrifugal spinning makes coarser, longer fibers (3.0–5.0 μm, up to 250 mm) with high tensile strength and erosion resistance — ideal for modules. High-pressure blowing makes finer, shorter fibers (2.0–3.0 μm) with lower thermal conductivity (0.08 versus 0.12 W/m·K at 400°C) and better thermal-shock stability, suited to high-purity products. Q: Why does alumina content matter for ceramic fiber? A: Alumina is the main driver of temperature resistance. Each 10% increase in Al₂O₃ raises the continuous-use temperature by about 150–200°C, and above 70% the crystal phase shifts to mullite, letting high-purity fiber (Al₂O₃ ≥72%) work above 1500°C long term, with a 2000°C peak. ### Rock Wool Raw Materials and Manufacturing Process: A Technical Study URL: https://www.rosetexwool.net/news/rock-wool-raw-materials-manufacturing-process/ 2026-08-11 | Author: Rosetexwool Editorial | Category: industry insight Summary: A technical study of rock wool raw materials — basalt, industrial slag, binders — and the six-stage manufacturing process, quality control and eco-friendly recycling routes. Introduction Rock wool (rockwool) is a key industrial thermal insulation material valued for its fire resistance, thermal performance and environmental profile. It is widely used in buildings, industry, marine and agriculture. This article examines the raw material composition, the full manufacturing workflow, the key process parameters that govern quality, and the eco-friendly production routes built on industrial waste recycling. 1. Raw Material Composition and Proportions Primary raw materials - Basalt — 60–70% of the mix. Typical chemistry: SiO₂ ~46%, CaO ~28%, Al₂O₃ ~15.6%, MgO 7–10%. - Dolomite / limestone — 10–25%, used to adjust the acidity coefficient and the melt temperature. Chemistry: CaO ~50–52%, MgO 10–12%. Auxiliary materials - Coke — 10–23%, acting as both fuel and flux to supply the heat for high-temperature melting. - Binder — phenolic resin at 5–8% of dry fiber in conventional production; modified phenolic or inorganic binders at 1–4% in eco grades. - Water repellent — 0.5–3%; silane-based agents (commercially available BS-series products) at about 1.5–2.5 kg per ton of rock wool. - Silane coupling agent — 0.3–0.8%, improving the fiber–binder interfacial bond and raising bending, internal-bond and tensile strength. - Flame retardant — 30–40% in fire-rated grades, mainly surface-modified alumina trihydrate and zinc borate, to extend the fire-resistance limit. Solid-waste utilization (eco rock wool) - Blast-furnace slag can replace basalt by up to 40–45%. - Fly ash at 5–10%. - Recycled rock wool recovery exceeds 85% after crushing and screening, then goes straight back into the furnace. - A representative eco recipe (parts): rock wool waste 40–45, basalt 35–42, limestone 4–6, coke 14–17, binder 1–4. This cuts reliance on natural minerals and lowers process carbon emissions, supporting China's dual-carbon strategy. 2. The Manufacturing Process (Six Stages) - Raw material preparation — crush basalt and dolomite to 10–30 mm, blend to the target ratio, screen, and dry to moisture ≤1%. Target chemistry: SiO₂ 40–50%, Al₂O₃ 15–25%, CaO+MgO 20–30%, Fe₂O₃ ≤10%. - High-temperature melting — cupola furnaces run at 1450–1500°C under slight positive pressure (0.05–0.1 MPa); all-electric furnaces run at 1600–2000°C with ±5°C control and cut energy use by more than 40% per ton. - Centrifugal fiberization — a four-roll spinner at 7000–15000 r/min draws the melt into fibers 3–7 μm in diameter (about one tenth of a human hair). Shot (non-fibrous particles) is held at ≤7%. - Binder & repellent application — a spray system at 0.2–0.3 MPa atomizes the binder and water repellent uniformly onto the fiber surface. - Forming & laying — suction draws the fiber onto a collection belt (50–100 mm mat, width up to 2200 mm, line speed 50–120 m/min); a pendulum lays multi-layer folds with CV ≤3.5%. - Curing & cutting — temperature gradient 180–200°C (inlet) / 220–240°C (middle) / 150–170°C (outlet), 30–45 min; slabs cut to standard sizes such as 1200×600×50 mm; final moisture ≤1% before shipment. 3. Key Process Parameters and Quality Control - Melting: basalt 1450–1500°C, slag 1300–1400°C, control precision ±5–10°C. - Fiberization: spinner speed 3000–15000 r/min (each +1000 r/min trims fiber diameter ~0.5–1 μm); melt viscosity 0.3–0.7 Pa·s; acidity coefficient MK = (SiO₂+Al₂O₃)/(CaO+MgO) ≥1.6, typically 1.8–2.2. - Curing: gradient as above, 30–45 min, curing oven 120–150 m long. - Physical control: density ±8%; tensile strength ≥7.5 kPa (high-density up to 15.2 kPa); compressive ≥40 kPa (up to 77.6 kPa). - Chemical control: MK ≥1.8; shot ≤7%; water repellency ≥98%. - Eco control: thermal conductivity ≤0.040 W/(m·K); all-electric melting reduces CO₂ by about 400 kg per ton. - Smart QC: online monitoring of temperature/pressure/CO, AI visual inspection of mat uniformity, 100% online waste re-melt, and VFD control that tunes fan flow to density. 4. Eco-Friendly Production and Waste Recycling - Slag pretreatment — crush to ≤10 mm, adjust MK to 1.4–1.8 and viscosity to 1–3 Pa·s, nitrogen stirring for homogeneity. - Recycled rock wool — recovery ≥85%, particle size 20–50 mm, metal impurities removed. - Incineration fly ash — low-temperature pyrolysis (<500°C) decomposes dioxins by >99%; water washing holds chloride <2%; salts (NaCl, KCl) are recovered. - Re-melt flow — recycled slag 88–92% blended with basalt 5–12%, conveyed to the furnace and co-melted. - Challenges & solutions — impurity control via XRF (Fe₂O₃ ≤10%); melt-temperature control via oxy-fuel combustion at 1300–1400°C; fiber-stability control via molecular simulation and a melt-composition database. - Market & policy — used in external wall insulation, fire barriers, industrial equipment, pipe insulation, marine and agricultural (soilless) cultivation; national standards require waste utilization ≥85% and define eco rock wool technical指标, with recycling subsidies available. 5. Conclusion and Outlook Basalt and dolomite remain the backbone of conventional rock wool, while industrial-waste recycling defines the eco-friendly direction. Product quality is decided by melting temperature (1450–1500°C), spinner speed (7000–15000 r/min), fiber diameter (3–7 μm) and the curing gradient. Quality control ultimately comes down to physical (density, tensile, compressive), chemical (acidity coefficient, shot, water repellency) and environmental (thermal conductivity, organic release, carbon) properties meeting industry standards. Looking ahead, rock wool production will move toward higher waste ratios (over 60%), smarter manufacturing (AI inspection, online monitoring), greener energy (electric furnaces replacing cupolas), more diversified products (high-density, ultra-fine, functional surfaces) and a full circular-economy loop of produce–use–recover–reuse. Related Reading - building insulation - green building insulation - fire-safe insulation Related products: Rockwool Insulation Blanket (Rock Wool Blanket), Rockwool Pipe Insulation for Steam Pipes, rock Wool Strips, rock wool Wired Insulation Blanket Related applications: Building, Cement, Iron & Steel FAQ: Q: What is rock wool made of? A: Primarily basalt (60–70%) with dolomite or limestone (10–25%) and coke (10–23%) as flux and fuel. Binders, water repellents and coupling agents complete the recipe. Eco grades replace up to 45% of the basalt with industrial slag and recycle more than 85% of production waste. Q: What temperature is used to melt rock wool? A: Cupola furnaces run at 1450–1500°C, while all-electric furnaces operate at 1600–2000°C with ±5°C control. Electric melting also cuts energy use by more than 40% per ton and reduces CO₂ emissions by roughly 400 kg per ton. Q: How fine are rock wool fibers? A: High-speed centrifugal spinners (7000–15000 r/min) produce fibers 3–7 μm in diameter — about one tenth the thickness of a human hair. Non-fibrous shot is held at or below 7% to protect product quality. ### Industrial Pipe Insulation Materials: A Pro Selection Guide URL: https://www.rosetexwool.net/news/industrial-pipe-insulation-materials/ 2026-08-09 | Author: Rosetexwool Editorial | Category: industry insight Summary: All five industrial insulation families compared by temperature band, form factor, fire class and lifetime cost, with a five-step selection method and links to every product page. Industrial pipe insulation is a decisive factor in energy efficiency, equipment safety, and service life across petrochemical, power, chemical, and district-heating operations. Specifiers have to weigh operating temperature, fire rating, mechanical strength, water resistance, form factor, and total installed cost — and those six variables rarely point at the same answer. This page is the hub for that decision. It covers all five industrial insulation material families used on process pipework — glass wool, rock wool, calcium silicate, ceramic fibre and nano aerogel — then routes you to the temperature band, the form factor, and finally the specific product page that matches. If you already know your service temperature, skip straight to the temperature-band table. The Five Material Families at a Glance Every industrial pipe insulation material in common use falls into one of five families. The table below is the shortlist; everything after it is refinement. Family | Continuous service temp | Short-term peak | Thermal conductivity (W/m·K) | Fire class | Density (kg/m³) | Compressive strength | Hydrophobicity | Where it wins | Where it loses | Glass wool | -120 °C to +400 °C | 500 °C | 0.030–0.042 | A1 non-combustible | 10–120 | low (non-load-bearing) | > 95 % | Lowest k-value per unit cost, lightest to handle, best value below 250 °C | Low temperature ceiling, dusts at sustained high temperature, weak mechanical strength | Rock wool | -260 °C to +650 °C | 800 °C | 0.030–0.047 | A1 non-combustible | 80–200 | 0.2–0.35 MPa (board) | > 98 % | Widest usable band, high strength, A1 fire safety, low cost | Higher water uptake than closed-cell alternatives, can dust under sustained vibration | Calcium silicate | +650 °C to +1000 °C | 1100 °C | 0.040–0.060 | A1 non-combustible | 170–280 | 0.35–0.53 MPa | > 98 % (through-section, not surface-only) | Dimensional stability, moisture and corrosion resistance, load-bearing | Heavy, higher conductivity than wool at low temperature, brittle at edges | Ceramic fibre | +800 °C to +1400 °C | 1600 °C | 0.05–0.15 (rising with temperature) | A1 non-combustible | 64–200 | low (needs composite or reinforcement) | > 95 % | Only practical choice above 1000 °C, light, removable and reusable | Highest cost per m³, low mechanical strength, dusty if mishandled | Nano aerogel | -200 °C to +650 °C | 800 °C | 0.014–0.024 | A1 (blanket form) | 160–240 | moderate | hydrophobic through-section | Thinnest solution for a given heat loss, roughly 5× service life, ideal where clearance is tight | Highest material cost, needs care at compression points | Read the conductivity column with a caveat: the figures are mean-temperature values, not room-temperature datasheet numbers. Ceramic fibre in particular degrades noticeably as mean temperature rises, which is why its range is so wide. Always size thickness from the curve, never from a single number. What Each Family Is Actually Like to Work With The table ranks materials by property; the notes below rank them by what happens on site. Glass wool is the easiest material on the list to handle and the fastest to cut, which makes it the default on long low-temperature runs where labour dominates the installed cost. Its limitation is structural rather than thermal — it has almost no compressive strength, so it needs mechanical protection anywhere it can be struck, and it will not survive sustained vibration without settlement. Rock wool is the generalist. It carries enough compressive strength to be used behind cladding on its own, tolerates vibration far better than glass wool, and holds A1 classification across its whole temperature range. It is denser and slightly heavier to handle, and it absorbs more water than closed-cell materials — which is a specification issue rather than a defect, since it is solved with a vapour barrier and correct jacketing. Calcium silicate is the structural material. It is the only family here that is routinely specified for buried service and for lines that have to carry load, and its moisture resistance runs through the section rather than sitting on the surface. It is heavy, it is brittle at cut edges, and it costs more per metre than wool — which is justified on high-temperature or wet duty and wasted at 200 °C. Ceramic fibre is the high-temperature specialist and, in blanket form, the most forgiving material to fit around irregular geometry. It has almost no mechanical strength on its own, so it is either reinforced, faced, or used in a composite build-up. It is also the material most often mis-specified at low temperature, where its cost is unjustifiable against wool. Nano aerogel solves a different problem from all four. It is not chosen because the temperature demands it but because the space does — where clearance is tight, where weight matters, or where re-insulating later would cost far more than the material. Judged on cost per unit of thermal performance it is expensive; judged on cost per year of service at a fixed heat loss on a congested line, it frequently wins. Temperature-Band Navigation Temperature is the first filter, and it usually eliminates three of the five families immediately. Start here. Band | Range | First choice | Alternative | Go to product | Cryogenic | -200 °C to -50 °C | Nano aerogel blanket | Cellular glass, elastomeric foam | nano aerogel insulation blanket | Low | -50 °C to +250 °C | Glass wool | Rock wool where mechanical strength matters | glass wool blanket · glass wool board | Medium | +250 °C to +650 °C | Rock wool | Calcium silicate in wet or buried service | rock wool pipe · rock wool board | High | +650 °C to +1000 °C | Calcium silicate | Ceramic fibre for complex geometry or weight limits | calcium silicate board · calcium silicate pipe | Ultra-high | +1000 °C to +1400 °C | Ceramic fibre | Polycrystalline mullite board above 1300 °C | ceramic fibre blanket · ceramic fibre board | Extreme | +1400 °C to +1600 °C | Polycrystalline mullite fibreboard | Ceramic fibre modules | polycrystalline mullite fibreboard | Two rules that override the table. First, always specify against the peak, not the normal operating point — a 600 °C line with 800 °C upsets belongs in the ceramic-fibre row, not the rock-wool row. Second, thermal cycling matters as much as absolute temperature: a line that swings 400 °C twice a day will fatigue a rigid calcium-silicate system long before it reaches its temperature limit. For cryogenic work the physics changes again — moisture drive is inward rather than outward, and the vapour barrier becomes the critical component rather than the insulation. That is a separate discipline, covered in our cryogenic pipe insulation guide. Form Factor Matrix Once the family is chosen, the form factor decides install speed, joint count, and long-term maintenance cost. This is where most specifications are either over- or under-engineered. Form | Typical use | Advantages | Limits | Pipe section (preformed shell) | Standard pipe diameters, long straight runs | Fastest install, fewest joints, consistent thickness | Standard diameters only; specials cost more | Blanket / roll | Large diameters, vessels, irregular geometry | Universal, easy to layer, forgiving on site | Needs banding, more joints, labour-intensive | Board / slab | Flat walls, equipment casings, load-bearing surfaces | High strength, dimensionally stable | Must be cut and mitred for curved surfaces | Paper / felt | Thin layers, gaskets, expansion joints | Very thin, easy to cut | Minimal strength, not a standalone thermal layer | Cloth / tape / rope | Valve and flange covers, removable jackets, sealing | Flexible, removable, reusable across shutdowns | Limited thickness, not for primary insulation | Module / special shape | Furnace linings, complex geometries | Pre-engineered, fast install, consistent density | Custom order, longer lead time | For a single-material deep dive on rock wool pipe sections — spec table, five-step production line, four-dimension supplier qualification and installation notes — see our pre-formed rock wool pipe insulation guide. For a step-by-step view of how those pipe sections are actually produced — melt, fibre, three-dimensional forming, curing and the lot certificate — see our rock wool pipe production walkthrough. The pattern worth remembering: pipe sections for straight runs, blankets for everything that is not a straight run, and removable textile jackets for anything you will have to open again. Mixing two forms on one line is normal and usually correct — a rock-wool pipe section on the run with a removable ceramic fibre cloth jacket at every valve and flange is a typical industrial specification. Our ceramic fibre rope and ceramic fibre tape pages cover the sealing end of that matrix in detail. Application Scenarios Petrochemical High-temperature lines — cracking furnace outlets, reformers and reactor effluent above 800 °C — belong to ceramic fibre, which is stable to 1000–1300 °C and forms readily into board, pipe or blanket for complex geometry. Where waterproofing matters alongside temperature, such as buried runs or humid coastal sites, calcium silicate is the safer call. Low-to-mid temperature lines — crude transfer, cooling water, instrument air, roughly -40 °C to +120 °C — are rock wool territory: A1 fire safety plus mechanical strength at low cost. Glass wool performs better than its price suggests on chilled-water and instrument lines because of its low conductivity at low mean temperature. Valves, flanges and removable items are where ceramic fibre removable blankets pay for themselves fastest — reusable across repeated shutdowns, which converts a recurring cost into a one-off. Power generation Boilers and main steam lines run 400–650 °C with peaks above 800 °C. Ceramic fibre blanket is the standard choice where heat retention is the goal; documented retrofits show surface temperature dropping from around 90 °C to below 30 °C, frequently retiring electric heat tracing entirely. Calcium silicate serves long high-temperature mains where dimensional stability and moisture resistance matter more than minimum thickness. Combined-cycle plant adds a wrinkle: frequent cycling between operating and standby favours materials that tolerate thermal movement. Our combined cycle power plant insulation guide treats that case specifically. District heating and cooling Buried long-distance mains are the strongest case for calcium silicate — its through-section moisture resistance holds thermal performance where a fibrous material would slowly wet out. Retrofit cases commonly show 30–40 % heat-loss reduction simply from replacing degraded insulation. Rigid polyurethane foam is cheaper and widely used but is fire-limited and needs a separate protective layer. Above-ground mains are usually rock wool (A1, strong, economical) or glass wool (light, lowest conductivity) depending on whether mechanical protection or thermal performance is the binding constraint. General industrial and HVAC Plant HVAC, process water, and compressed-air headers below 250 °C are the volume end of the market. Glass wool wins on cost per unit of thermal performance; rock wool wins where the line can be struck, walked on, or exposed. Neither needs the high-temperature families, and over-specifying here is the single most common source of wasted insulation budget. The Five-Step Selection Method Work through these in order. Skipping step 1 is what produces most failed specifications. - Fix the temperature envelope. Continuous operating temperature, peak or upset temperature, and cycling frequency. This selects the family — use the temperature-band table above. - Fix the fire requirement. Process plants and power stations generally require A1 non-combustible material. All five families here qualify in their inorganic forms; organic foams do not, which is why they need a separate fire layer. - Fix the mechanical and environmental duty. Vibration, load-bearing, burial, ambient humidity, and chemical exposure. Vibration argues against brittle rigid systems; burial argues strongly for calcium silicate; chloride or sulphur environments argue against certain binder systems. - Fix the form factor and thickness. Pipe sections on straight runs, blankets elsewhere, removable jackets at maintenance points. Size thickness from the economic-thickness calculation, not from a rule of thumb — see below. - Fix the lifetime cost. Compare installed cost per metre against service life, maintenance frequency and energy saved. Aerogel looks expensive per cubic metre and is often cheapest per year of service at a given heat loss. Thickness, Heat Loss and Surface Temperature Three separate calculations govern thickness, and the governing one changes with the service. Economic thickness balances the marginal cost of insulation against the marginal value of the heat saved. Above roughly 300 °C on a continuously operating line, the optimum thickness almost always exceeds what a rule-of-thumb table suggests. Surface temperature for personnel protection caps at around 60 °C for surfaces within reach. This is a hard safety limit, not an optimisation. Condensation control applies to chilled and cold service, where the constraint is keeping the outer surface above the local dew point. The calculation uses dew point rather than a fire or economic criterion, and ships and offshore platforms have their own version of it — our marine insulation thermal and acoustic specifications guide works through the method. For pipe-specific thickness by diameter and temperature, the dedicated pyrogel insulation thickness guide carries the full tables. This hub deliberately stops at method rather than duplicating them. For the unit-by-unit view — how those material choices change between distillation columns, cracking furnaces, storage tanks and heat-traced lines — our petrochemical plant insulation selection by process unit works through each process area. Corrosion Under Insulation: The Failure Mode That Costs the Most Insulation does not fail thermally as often as it fails by destroying the pipe underneath it. Corrosion under insulation (CUI) is the largest single cause of unplanned pipework replacement in process plant, and it is almost always a specification and detailing problem rather than a material defect. The mechanism is simple. Water gets in — through a failed joint, a damaged jacket, a missing seal at a protrusion, or simply by condensation during a shutdown — and the insulation holds it against the steel. The pipe stays wet at a temperature that happens to be ideal for corrosion, out of sight, indefinitely. Three design decisions control the risk: Material selection. Closed-cell and through-section hydrophobic materials — calcium silicate and aerogel blanket — hold far less water than fibrous materials. Where a fibrous material is chosen for other reasons, a vapour barrier is not optional. Jacketing and sealing. The metal or non-metallic jacket is the actual waterproofing layer, not the insulation. Every joint, termination, valve, and support penetration is a potential entry point, and the specification should detail them individually rather than leaving them to site practice. Our industrial pipe insulation types: fittings, valves and supports guide breaks those points down one by one — elbows, tees, valve bodies and support shoes — because that is where the heat loss concentrates. Operating temperature. CUI risk peaks roughly between 50 °C and 150 °C for carbon steel — warm enough to drive corrosion, cool enough that water does not flash off. Lines that cycle through that band are higher risk than lines that sit permanently above or below it. Worth noting for specification: drain holes, vents, and inspection plugs are cheap to include at design stage and effectively impossible to retrofit later. Most CUI mitigation is decided in the detailing, not in the material schedule. Installation Details That Decide Real-World Performance Two identical material specifications can produce installations with very different service lives. The differences are almost always in the details. Joints and seams. On multi-layer work, stagger the joints between layers — aligned joints are a direct thermal bridge and a direct water path. Butt joints tightly rather than leaving gaps; a 5 mm gap in a fibrous layer costs more heat than 10 mm of additional thickness gains. Compression. Every material has a practical compression limit, and over-tightening banding to "make it fit" is a common site error. Compressing a blanket beyond its design point raises its conductivity measurably and can crush a closed-cell structure permanently. Support and hanger details. Insulation is routinely compromised at pipe supports, where the load path cuts through the thermal layer. Pre-formed inserts or high-density calcium silicate board at support points prevent both crushing and the thermal short that would otherwise form. Weatherproofing continuity. The jacket must be continuous across the whole run, including bends, tees, and terminations. Most moisture ingress starts at a termination rather than in the middle of a run, which is why termination detailing deserves as much attention as the insulation itself. Removable items. Every valve, flange, and instrument that will need access should have a removable jacket from the start. Retrofitting them later costs several times more than specifying them initially, and the maintenance savings begin on the first shutdown. Standards and Compliance Specifications should name the standard, not just the property. The common references: - ASTM C547 — mineral fibre pipe insulation (rock wool and glass wool preformed sections) - ASTM C533 — calcium silicate block and pipe insulation - ASTM C892 — high-temperature ceramic fibre blanket - ASTM E84 / EN 13501-1 — surface burning characteristics and Euroclass fire classification; A1 is the non-combustible grade - EN 14303 / EN 14306 — factory-made mineral wool and calcium silicate products for building equipment and industrial installations - ISO 9229 — thermal insulation vocabulary, useful for getting unambiguous tender documents Naming the standard in the procurement document is what makes a rejected delivery enforceable. A datasheet alone is not a specification. Product Directory by Family Rock wool — blanket · board · pipe sections · strips · wired blanket · glass-mesh faced blanket · acoustic panels Glass wool — blanket · board · spec & selection guide Ceramic fibre — blanket · board · board alternative · plus blanket · bulk · paper · cloth · tape · rope · modules · special shapes Calcium silicate — insulation board · pipe sections · high-density board Nano and high-performance — nano aerogel blanket · nano insulation board · polycrystalline mullite fibreboard Composite — composite silicate plate Future Trends Aerogel adoption continues to grow wherever space or weight is constrained. Ultra-low conductivity and long service life offset high material cost on lines that are expensive to re-insulate, and the material is moving from niche retrofit into standard specification on offshore and compact plant. Composite systems — ceramic fibre backed with calcium silicate, or foil-faced glass wool — combine thermal and moisture performance in one build-up, and are increasingly pre-engineered rather than assembled on site. Removable and instrumented insulation is the visible trend on maintenance-heavy plant: textile jackets that can be opened and refitted in minutes, increasingly with embedded temperature sensors that turn insulation inspection into a monitoring task rather than a shutdown task. Tighter energy-efficiency regulation keeps raising the bar on allowable heat loss, which favours inorganic, durable materials with stable long-term conductivity over cheaper materials that degrade. Conclusion No universal industrial insulation material exists, and any supplier claiming otherwise is selling rather than specifying. The sequence that works: fix the temperature envelope, choose the family, choose the form factor, size the thickness from the governing criterion, then compare lifetime cost rather than purchase price. Ceramic fibre for refining high-temperature lines. Calcium silicate where moisture or load is the constraint. Rock wool across the broad medium band. Glass wool wherever the temperature stays below 250 °C. Aerogel where clearance is tight or re-insulation is expensive. Validate with testing, specify against a named standard, and the installation will outlast the plant's next turnaround. Related Reading - industrial pipe insulation types - cryogenic pipe insulation guide - pyrogel insulation thickness chart - calcium silicate buyer's guide - high temperature insulation wool ratings - petrochemical pipe insulation - power plant piping insulation - cryogenic insulation systems Related products: Calcium Silicate Pipe, Ceramic Fiber Special Shaped, Ceramic Fiber Plus Blanket, Nano Aerogel Insulation Blanket, Rockwool Pipe Insulation for Steam Pipes Related applications: Iron & Steel, Petrochemical, Building FAQ: Q: Which pipe insulation material is best above 800 °C? A: Ceramic fibre is the practical choice above 800 °C and remains stable to 1400 °C in continuous service, with a short-term peak around 1600 °C. Calcium silicate is an alternative up to roughly 1000 °C where moisture resistance or dimensional stability matters more than weight. Above about 1300 °C, polycrystalline mullite fibreboard is the usual step up. Q: Why is calcium silicate preferred for buried heating mains? A: Because its moisture resistance runs through the section rather than sitting on the surface. A buried line is permanently exposed to groundwater drive, and fibrous materials that rely on a surface treatment will eventually wet out and lose most of their thermal performance. Calcium silicate keeps its shape and its conductivity in that environment, which is why retrofit projects commonly report 30–40 % heat-loss reduction after replacing degraded insulation. Q: What is the most cost-effective pipe insulation for low-to-mid temperatures? A: Glass wool below 250 °C and rock wool from 250 °C to 650 °C. Glass wool has the lowest conductivity per unit cost in the low band and is the lightest to handle; rock wool adds mechanical strength and a higher temperature ceiling for a modest cost increase. Calcium silicate and ceramic fibre are both over-specified in this range unless moisture or fire duty demands them. Q: How do I choose between glass wool and rock wool for the same pipe? A: Temperature first: glass wool tops out around 400 °C, rock wool reaches 650 °C. If both are within range, decide on mechanical duty — rock wool is stronger and better under vibration or where the line can be struck, while glass wool is lighter, has marginally lower conductivity at low mean temperature, and is cheaper. Our comparison of the two covers the seven differences that actually decide the spec. Q: Is aerogel worth the extra cost for pipe insulation? A: It is worth it where clearance is tight, where weight matters, or where re-insulating the line later would be expensive — offshore platforms, congested pipe racks, and retrofit work on live plant are the classic cases. Aerogel achieves the same heat loss at roughly a third to a half of the thickness of mineral wool, and has a service life several times longer. On a simple, accessible, low-temperature line with no space constraint, mineral wool remains the better value. Q: What thickness of pipe insulation should I specify? A: Whichever of three criteria governs: economic thickness on hot continuously-running lines, a surface temperature cap around 60 °C for personnel protection, or dew-point control on chilled and cold service. Calculate all three and take the largest. Rules of thumb systematically under-insulate hot lines, because the economic optimum is usually thicker than intuition suggests. Q: Do I need a vapour barrier on pipe insulation? A: On cold and cryogenic service, yes — without one, moisture drives inward, condenses within the insulation, and destroys thermal performance while corroding the pipe underneath. On hot service the requirement depends on whether the insulation can get wet; calcium silicate generally does not need one, while rock and glass wool do in outdoor, buried or wash-down locations. Q: What fire classification should industrial pipe insulation meet? A: A1 non-combustible to EN 13501-1 is the standard requirement for process plant and power generation. All five inorganic families in this guide — glass wool, rock wool, calcium silicate, ceramic fibre and aerogel blanket — are available in A1 grades. Organic foams such as polyurethane are not, and require a separate fire-protective layer where a fire rating applies. Q: Can different insulation materials be combined on the same pipe run? A: Yes, and it is often the right answer. A common build-up is a preformed pipe section along the straight run, blanket on bends and irregular geometry, and removable textile jackets at valves and flanges. Multi-layer systems also work well — a high-temperature inner layer with a lower-cost outer layer — provided the layers are chemically compatible and mechanically secured. Q: Which standards should a pipe insulation specification name? A: ASTM C547 for mineral fibre pipe sections, ASTM C533 for calcium silicate, ASTM C892 for high-temperature ceramic fibre blanket, and EN 13501-1 or ASTM E84 for fire classification. Naming the standard in the procurement document is what makes a rejected delivery enforceable; a supplier datasheet alone is not a specification. ### India's High-Temperature Insulation Materials Market: Growth, Drivers & Material Trends URL: https://www.rosetexwool.net/news/india-high-temperature-insulation-market/ 2026-08-07 | Author: Rosetexwool Editorial Team | Category: industry insight Summary: India's thermal insulation market is forecast to grow from USD 203M (2024) to USD 383M (2032) at a 7.29% CAGR. Compare rock wool, glass wool, ceramic fiber and calcium silicate across building, indus… Market Overview India — the world's second-most-populous country and one of its fastest-growing major economies — is undergoing a structural shift in its high-temperature insulation materials market. Driven by extreme climate conditions, expanding industrial capacity and the Make in India policy, four material families — rock wool, glass wool, ceramic fiber and calcium silicate — are each carving out distinct roles tailored to local demand. This report compares the physical properties, industry applications and policy environment of these four materials, mapping their typical use cases and market outlook in India. Material Properties & Temperature Ranges Material | Key Composition | Thermal Conductivity (W/m·K) | Max Service Temp (°C) | Fire Class | Density (kg/m³) | Price (INR/t) | Key Advantage | Rock wool | Basalt | 0.035–0.042 | ≥1000 | A (non-combustible) | 100–150 | 120,000–180,000 | Excellent fire performance, easy install, recyclable | Glass wool | Silica sand, soda ash | 0.032–0.040 | ≤350 | B (limited combustibility) | 50–80 | 80,000–120,000 | Soft, easy install, low cost | Ceramic fiber | Alumina, silica | 0.03–0.12 (at 600°C) | 1000–1400 | A (non-combustible) | 200–260 | 250,000–400,000 | Extreme-temp resistance, lightweight, low heat capacity | Calcium silicate | Silicate, lime | 0.04–0.05 (at 400°C) | 900–1100 | A (non-combustible) | 220–270 | 100,000–150,000 | Local raw materials, low cost, high strength | Rock wool is produced from basalt melted above 1450°C and spun into fine fibres. It offers non-combustible A-class fire performance and service temperatures ≥1000°C, with low thermal conductivity (0.035–0.042 W/m·K). Glass wool (silica sand, soda ash, limestone) is valued for low cost and easy handling. Its conductivity is close to rock wool (0.032–0.040 W/m·K) but its service limit is lower (≤350°C), restricting it to HVAC and acoustic applications. Ceramic fiber (alumina + silica) — available as traditional RCF or the safer AES grade — leads on temperature (1000–1400°C) and keeps conductivity low at high heat. It is the preferred choice for energy-intensive industry, though it is the most expensive (250,000–400,000 INR/t). Calcium silicate (silicate + lime, hydrothermally processed) performs well at 900–1100°C with good mechanical strength. Its biggest edge in India is abundant local raw material and lower cost (100,000–150,000 INR/t), making it dominant for mid-to-high-temperature industrial piping in cement and power. Building-Sector Applications India's construction industry is shifting from traditional to modern insulation materials, with the ECBC (Energy Conservation Building Code) as the key driver. - Rock wool — Commercial facade/roof insulation (ECBC 2024 mandates A-class fire materials). - Glass wool — HVAC duct insulation, acoustic ceilings/partitions, light-gauge steel roof insulation in western/eastern coastal zones. - Calcium silicate — fire-wall and fire-door linings; high-temp-area building insulation near cement/steel plants; high-temperature piping in hospitals and pharma. Industrial Applications India's surge in steel, cement, petrochemical and power capacity is creating huge demand. Metallurgy - Rock wool: electric-arc and blast-furnace linings, high-temp building insulation. - Ceramic fiber: ladle/tundish linings and furnace-seal — can cut steelmaking energy use 15–20%. - Calcium silicate: heating/soaking/annealing furnace piping. Petrochemical - Ceramic fiber: reformers, crackers and piping (~200 t per million tonnes of ethylene capacity). - Calcium silicate: low-temperature tank/filter piping; good corrosion resistance. - Glass wool: low-temp process piping and acoustics (limited by ≤350°C). Cement - Calcium silicate: preheater, precalciner, tertiary air duct, kiln hood, cooler insulation (boards rated to 1050°C). - Ceramic fiber: kiln linings, expansion-joint repair, hot piping. Power - Ceramic fiber: supercritical boiler linings, hot piping (NTPC invested USD 210M in boiler upgrades in 2023). - Calcium silicate: cooling-water and mid-temp steam piping. - Rock wool: plant building insulation and fire compartments (control rooms, substations, cable trenches). - Glass wool: non-high-temp plant insulation and acoustics. Regional Demand Differences - North (Delhi, Haryana, UP) — large temperature swings; strict fire codes push A-class rock wool/ceramic fiber. - West (Maharashtra, Gujarat) — industrial heartland; ceramic fiber and rock wool dominate in petrochemical/steel. - South (Tamil Nadu, Karnataka) — major cement base; calcium silicate strong; rock wool rising with green building. - East (West Bengal, Odisha) — power & cement hubs; calcium silicate and ceramic fiber widely used. Policy & Market Outlook ECBC 2024 lowers the mandatory threshold from 500 kW to 100 kW connected load, mandates A-class fire materials in commercial buildings, and raises efficiency bars — directly boosting rock wool and ceramic fiber. PLI (Production-Linked Incentive) does not list insulation directly, but its import restrictions and localization pull have pushed international makers to build local plants. Downstream steel/petrochemical/power support indirectly lifts insulation demand (India targets 30 Mt steel capacity by 2030). Market size: India's thermal insulation market was ≈USD 203M in 2024, projected ≈USD 383M by 2032 (CAGR 7.29%). - Rock wool: 8–10% CAGR (ECBC + localization) - Ceramic fiber: 6–8% CAGR (steel/petrochemical) - Calcium silicate: ≈6% CAGR (local raw material + cement) - Glass wool: ≈4% CAGR (price pressure) Conclusion Material roles are clearly differentiated: rock wool leads building fire and high-temp industrial insulation; ceramic fiber owns extreme-high-temp industry; calcium silicate wins mid-high-temp industrial piping; glass wool holds low-temp pipe and acoustic niches. Policy (ECBC 2024, Make in India) is reshaping the market structure, and regional needs vary sharply. Success in India means understanding local requirements, developing adaptive products, building local service networks, and tracking policy shifts. Related Reading - building insulation materials - power generation insulation - petrochemical insulation Related products: Calcium Silicate Insulation Board, Ceramic Fiber Plus Blanket, Glass Wool Blanket, Composite Silicate Plate, Rockwool Insulation Blanket (Rock Wool Blanket), Rockwool Insulation Slabs — Rock Wool Board Related applications: Cement, Power Generation, Petrochemical FAQ: Q: What is the size of India's thermal insulation market? A: India's thermal insulation market was valued at approximately **USD 203 million in 2024** and is projected to reach **USD 383 million by 2032**, growing at a **CAGR of 7.29%**. Q: Which insulation material is growing fastest in India? A: **Rock wool** is forecast to grow fastest at **8–10% CAGR**, driven by ECBC 2024's mandatory A-class fire requirement for commercial buildings and rising local manufacturing under the Make in India / PLI push. Ceramic fiber follows at 6–8% CAGR on steel and petrochemical demand. Q: How does ECBC 2024 affect insulation material demand? A: ECBC 2024 lowered the mandatory coverage threshold from 500 kW to 100 kW connected load, **requires A-class (non-combustible) fire materials** in commercial buildings, and raised efficiency standards — directly increasing demand for rock wool and ceramic fiber in the building sector. Q: Why is calcium silicate popular in Indian cement and power plants? A: Calcium silicate uses **abundant local Indian raw materials**, costs less (100,000–150,000 INR/t), and offers good mechanical strength and 900–1100°C service — making it the dominant choice for preheater, precalciner, kiln and boiler piping insulation. ### Rock Wool Insulation for Marine & Offshore Engineering: Applications & Benefits URL: https://www.rosetexwool.net/news/rock-wool-marine-offshore-applications/ 2026-08-06 | Author: Rosetexwool Technical Team | Category: industry insight Summary: Rock wool (mineral wool) marine insulation: A-60 fire rated, salt-resistant, soundproof. For ship pipes, bulkheads, cabins & offshore platforms. IMO SOLAS compliant. Why Rock Wool Is the Material of Choice at Sea Rock wool (stone wool / mineral wool) is an inorganic insulation made by melting natural basalt and diabase rock above 1450C and spinning the melt into fine fibres (3-7 microns), then bonding them with an eco-friendly binder. With a density range of 80-150 kg/m3, it delivers a rare combination of fire safety, thermal efficiency and marine durability that organic foams simply cannot match. In ships and offshore structures the environment is brutal: high salt spray, constant vibration, humidity and temperature swings from -50C polar waters to 1000C engine rooms. Rock wool thrives in exactly these conditions. Key properties: - Fire: melting point above 1000C; A-60 class fire rated (back-face temperature rise under 140C within 60 minutes), fully compliant with the IMO SOLAS convention. - Thermal: thermal conductivity 0.038-0.042 W/(m·K), lower than glass wool, so less material is needed for the same effect. - Marine durability: hydrophobicity above 98%, water absorption below 1%, and over 90% strength retention after 2000 hours of salt-spray testing. - Comfort & safety: asbestos-free, fluorine-free, with smoke toxicity meeting IMO FTP Code Part 2. Primary Applications on Ships and Offshore Structures 1. Fire Division Systems Fire compartments are the backbone of maritime safety, and rock wool's A-class rating makes it the default choice. The material rules behind those ratings — which products qualify for A-15, A-30 and A-60 divisions, and what the IMO FTP Code actually tests — are set out in our marine fire insulation guide. - Bulkheads and decks: A-60 rock wool sandwich panels (50-100 mm) fixed on metal studs separate engine rooms, cargo holds and accommodation blocks. - H- and A-class structures: certified A-30 and A-60 fire-rated boards protect decks and bulkheads; in fire testing a typical LNG-carrier machinery-space panel held a back-face temperature of just 112C against the 140C limit. - Fire doors and partitions: composite rock wool boards are used in doors and divisions between critical zones such as machinery spaces, cargo areas and living quarters. 2. Pipe and Equipment Insulation Ships and offshore facilities run kilometres of piping that must stay hot, safe and efficient. - Steam lines: rock wool pipe sections rated to 600C wrap steam mains, cutting heat loss and preventing burns. - Subsea pipelines: specialised deep-sea, high-pressure-rated insulation systems keep subsea hot lines stable under extreme external pressure. - Equipment: engines, heat exchangers and other high-temperature plant are insulated with rock wool for both safety and energy efficiency. 3. Cabin Comfort — Thermal and Acoustic Modern vessels demand liveable, quiet spaces. - Cold stores: high-density rock wool (120 kg/m3, conductivity 0.036 W/(m·K)) on cruise-ship cold stores delivers roughly 30% energy savings versus traditional materials. - Accommodation soundproofing: composite rock wool acoustic boards (NRC at least 0.8) drop interior noise below 45 dB, sharply improving comfort. - Polar vessels: aerogel-modified rock wool (conductivity 0.028 W/(m·K)) withstands -50C, holding heat during polar voyages. 4. Special Requirements for Naval and Defence Vessels Military ships push material limits further. - EM shielding: aluminium-coated rock wool attenuates electromagnetic waves by 30 dB for command and radar spaces. - Lightweighting: low-density designs (under 150 kg/m3) trim hull weight, boosting manoeuvrability and fuel efficiency. - Impact protection: four-layer composites (metal face / rock wool board / foam-aluminium core / metal backing) add blast and impact resistance. 5. Offshore Platforms Offshore oil, gas and wind structures demand even stricter performance. - Platform fire systems: rock wool builds fire barriers across fire zones, piping and equipment rooms to stop fire spread. - High-temperature plant: drilling and processing equipment is insulated to protect personnel and conserve energy. - Structural insulation: divisions between living and working areas provide temperature control and comfort. Rock Wool vs Other Marine Insulation Materials Material | Conductivity W/(m·K) | Sound reduction dB(A) | Fire class | Corrosion resistance | Marine rock wool | 0.038-0.042 | 30-46 | A class | Excellent | Glass wool | 0.045-0.055 | 25-35 | B class | Moderate | Polyurethane foam | 0.031-0.035 | 28-38 | B class | Poor | Aerogel composite | 0.015-0.024 | 35-45 | A class | Excellent | Against glass wool and polyurethane, rock wool wins on fire safety (fully non-combustible versus B-class organics) and on high-temperature stability (glass wool softens and fails when hot). Aerogel matches rock wool's A-class rating but at far higher cost, so the two are increasingly combined. On cost, rock wool's initial price sits about 30% above glass wool, yet a 15-20 year service life, lower maintenance and hull-weight fuel savings make it cheaper across the full lifecycle. It is also easy to cut and fit, and modular prefabricated systems speed up shipyard installation. Innovation and Future Directions Greener chemistry. Formaldehyde-free binders (lignin or plant protein) cut VOC emissions by 50-80%, and dust-free rock wool with fibre emission under 0.1 mg/m3 raises handling safety. Some producers now use inorganic binders made from industrial waste. Functional composites. Rock wool-aerogel boards reach 0.012-0.032 W/(m·K) at 40% less thickness and over 1 MPa strength for LNG-duty extremes. Graphene coatings push temperature resistance to 1200C, and aluminium-coated variants serve electromagnetic-shielding needs. Smart manufacturing. Digital-twin furnace models, AI visual inspection for fibre uniformity, and 3D simulation design tools are raising quality consistency and lowering energy use. System solutions. The industry is moving from single materials to modular prefabricated insulation, BIM-integrated design and IoT-based lifecycle monitoring. Market Outlook The global marine rock wool market reached about USD 1.8 billion in 2023 and is forecast to grow at a 6-8% CAGR through 2030, led by green-ship and emissions rules, smarter vessels, and rising polar and deep-sea demand. New-energy ships — battery rooms and fuel cells — are opening fresh fire-and-insulation roles for rock wool. Meeting International Standards Producers increasingly secure DNV, LR and ABS class-society certifications so products clear global markets. With aerogel costs falling, rock wool answers through modular design and rock wool-aerogel hybrids, while custom products target specific vessel and platform scenarios. Conclusion From a single fire-and-insulation material, rock wool has become an integrated marine system — fire safety, noise control and energy savings in one. Its A-class fire performance, superior thermal and acoustic behaviour, extreme-environment durability and full-lifecycle economy make it indispensable for ships and offshore engineering. As vessels green, smart and push into harsher seas, rock wool will keep guarding safe, comfortable and efficient operation worldwide. Rock wool is the default for most of those duties, but not the only option. Where a spec needs conductivity, condensation and acoustic numbers compared across all five material families — rock wool, glass wool, calcium silicate, ceramic fibre and aerogel — our marine insulation specifications across all five material families guide lays out the side-by-side data and the selection matrix by zone. Related Reading - marine insulation - cryogenic marine insulation - fire-rated marine insulation For A-60 insulation inside the engine room and machinery spaces specifically, see our engine room & machinery space A-60 guide. FAQ: Q: What is rock wool used for on ships and offshore platforms? A: Rock wool is used for A-class fire divisions (bulkheads, decks, fire doors), pipe and equipment insulation, cabin acoustic and cold-store insulation, naval EM-shielding and offshore-platform fire and structural barriers. Q: Is rock wool fire rated for marine use? A: Yes. Marine rock wool is A-60 class fire rated with a melting point above 1000C and meets the IMO SOLAS convention, making it the standard non-combustible material for ship fire compartments. Q: Does rock wool resist salt water and corrosion at sea? A: Rock wool is over 98% hydrophobic with under 1% water absorption and retains over 90% strength after 2000 hours of salt-spray testing, so it performs reliably in high-salt marine and offshore environments. Q: Can rock wool reduce noise in ship cabins? A: Yes. Composite rock wool acoustic boards with an NRC of at least 0.8 can lower interior noise below 45 dB, significantly improving comfort in accommodation and working spaces. Q: What rock wool products insulate marine pipes and equipment? A: Rock wool pipe sections rated to 600C insulate steam and process lines, while boards and blankets protect engines, heat exchangers and high-temperature plant; specialised deep-sea systems insulate subsea pipelines. Q: Is rock wool suitable for offshore oil and gas platforms? A: Absolutely. Offshore platforms use rock wool for fire barriers, high-temperature equipment insulation and structural divisions between living and working areas, often supported by DNV, LR and ABS class certifications. ### Rock Wool Insulation in Metallurgy: Applications, Benefits & Slag Recycling URL: https://www.rosetexwool.net/news/rock-wool-insulation-metallurgy-applications/ 2026-08-05 | Author: Rosetexwool Technical Team | Category: industry insight Summary: Rock wool (mineral wool) insulation in metallurgy: high-temperature pipe and furnace protection, A1 fire rating, 600C+ resistance, and steel slag recycling into sustainable insulation materials. Why Metallurgy Relies on Rock Wool Insulation Metallurgical plants operate at extreme temperatures. Blast furnaces, electric-arc furnaces, hot-rolling mills and slag-handling systems all need thermal insulation that survives heat, vibration and corrosive gases. Rock wool (stone wool / mineral wool) meets these demands: it is non-combustible, thermally stable above 600C, chemically inert, and increasingly produced from metallurgical slag itself — turning industrial waste into high-value insulation. This article explains where rock wool is used in metallurgy, the performance advantages that matter on the plant floor, and the economic and environmental value of converting steel slag and manganese slag into rock wool products. Key Applications of Rock Wool in the Metallurgy Industry 1. High-Temperature Pipe Insulation Metallurgy uses miles of steam, hot-water and process pipes carrying fluids above 600C. Rock wool pipe insulation (also called mineral wool pipe insulation / rock wool pipe section) is the standard solution because it: - Withstands continuous service temperatures above 600C. - Lowers surface temperatures to safe working levels. - Reduces heat loss by an estimated 28-35% in practical installations. Real-world examples include steel-mill steam lines, continuous-casting cooling-water pipes, electric-arc-furnace flue ducts, and hot slag conveying systems. In one project, a steel plant using rock wool pipe insulation reduced surface temperature from 70C to 42C while cutting annual energy costs by roughly RMB 200,000. 2. Furnace and Equipment Thermal Protection Besides pipes, rock wool board and blanket protect large stationary equipment: - Blast furnace body and trough covers – anchored rock wool composites lower shell temperatures and prevent thermal shock damage. - Electric-arc furnace walls – high-density rock wool / ceramic-fiber composite boards rated >=1000C reduce radiant heat to personnel and adjacent equipment. - Hot-rolling reheating furnaces – 1200C kiln projects report surface temperatures dropping from 65C to below 30C after installing high-temperature rock wool boards. - Dust collectors and baghouses – rock wool lagging prevents condensation, moisture buildup and dust caking that causes blockages. 3. Slag-to-Wool Recycling: Closing the Loop A growing share of rock wool raw material comes from metallurgical slag: - Steel slag / blast-furnace slag is melted and fiberized into rock wool. - Manganese slag and silicomanganese tailings are processed into mineral wool boards. - Red mud–steel slag co-processing has demonstrated full conversion of both residues into rock wool plus recovered metallic iron. A representative project in Hancheng, Shaanxi, consumes 360,000 tonnes/year of blast-furnace slag, saves 31,700 tonnes of standard coal and avoids 82,300 tonnes of CO2 annually. Another plant in Inner Mongolia processes 100,000 tonnes/year of manganese slag, creating both environmental benefit and new revenue. Performance Advantages That Matter in Metal Production High-Temperature Stability Rock wool is rated for continuous use above 600C and tolerates short-term peaks to 800C. Its thermal conductivity is typically 0.035–0.040 W/(m·K), providing reliable thermal resistance where organic insulations fail. A1 / Non-Combustible Fire Rating Rock wool melts above 1000C and is classified as GB 8624 A1 non-combustible. It does not burn, melt, or release toxic smoke — critical for fire compartments, cable tunnels and hot-work areas in steel plants. Chemical and Corrosion Resistance Rock wool has an acidity coefficient >=1.6, contains no fluoride or chloride ions, and resists attack from acidic or alkaline process gases. It will not corrode stainless steel or carbon-steel substrates under normal operating conditions. Hydrophobicity and Moisture Protection With a water-repellent treatment, rock wool reaches a water repellency rate >=98% (GB/T 25975). When paired with a vapour barrier and metal or composite jacket, it performs reliably in humid, wash-down environments. Mechanical Durability High-density rock wool board (>=120 kg/m3, compression strength >=40 kPa) withstands foot traffic, vibration, thermal cycling and mechanical impact on furnaces, platforms and ductwork. Economic and Environmental Benefits Energy Savings and Maintenance Reduction - Field measurements show heat-loss reductions of 28–35%. - One steel mill reported an 8% drop in converter gas-line energy consumption and a 30% maintenance-cost reduction after switching to rock wool pipe insulation. - Service life typically reaches 15–20 years, compared with 1–2 year replacement cycles for some organic alternatives. Solid-Waste Valorization - Converting slag to rock wool diverts waste from landfill and lowers disposal risk. - It supports national circular-economy and carbon-reduction policies. - Tax incentives under China's resource-utilization catalogue can return up to 70% of VAT for qualified slag products. Productivity and Safety - Lower surface temperatures improve worker safety and reduce heat-stress exposure. - Stable insulation reduces process temperature swings, improving product quality and equipment reliability. Technology Trends Higher-Density, Higher-Temperature Products New formulations push density above 120 kg/m3 and raise continuous-use temperatures, while sandwich composite panels combine steel or aluminum facings with rock wool cores for structural and thermal performance in one panel. Rock Wool–Ceramic Fiber and Aerogel Composites Hybrid insulation layers combine rock wool with ceramic fiber or silica aerogel to achieve lower thermal conductivity (0.018–0.030 W/(m·K)) and longer service life in the hottest zones. Smart Manufacturing and Slag Heat Recovery Modern plants use automated melting, fiber-forming and visual-inspection lines. Slag sensible-heat recovery systems transfer waste heat back into production, cutting electricity by roughly 50 kWh per tonne of product and reducing manufacturing cost by up to 41%. Conclusion Rock wool insulation is no longer just a thermal product for metallurgy — it is an integrated part of plant energy management, fire safety and slag valorization strategy. Whether protecting 600C steam lines, lining reheating furnaces, or converting steel slag into sustainable building materials, rock wool delivers measurable performance, durability and circular-economy value. For metallurgical operators evaluating insulation upgrades, specifying high-density, high-temperature rock wool with the correct facing and installation details is the lowest-risk path to lower energy bills, safer surfaces and reduced environmental impact. Related Reading - steel industry insulation - cement industry insulation Related products: Rockwool Insulation Blanket (Rock Wool Blanket), Rockwool Pipe Insulation for Steam Pipes, rock wool Wired Insulation Blanket Related applications: Iron & Steel FAQ: Q: What temperature can rock wool insulation withstand in metallurgical applications? A: Industrial rock wool is rated for continuous service above 600C and can tolerate short-term peaks up to 800C, making it suitable for steam pipes, furnaces and hot-slag handling systems in steel and non-ferrous metal plants. Q: Is rock wool fireproof for steel mills and foundries? A: Yes. Rock wool is classified as GB 8624 A1 non-combustible. It does not burn or release toxic smoke above 1000C, so it is widely used for fire compartments, cable tunnels and high-temperature equipment enclosures. Q: How does rock wool pipe insulation reduce energy loss? A: Rock wool pipe sections create a dense, low-conductivity thermal barrier. Field projects report heat-loss reductions of 28–35%, surface temperatures falling from 70C to safe levels below 45C, and payback periods typically under five years. Q: Can metallurgical slag really be turned into rock wool? A: Yes. Blast-furnace slag, steel slag and manganese slag are melted and fiberized into rock wool or mineral wool board. Commercial projects convert hundreds of thousands of tonnes of slag per year, cutting CO2 emissions and creating revenue from waste. Q: What is the service life of rock wool insulation in a metallurgy plant? A: When correctly installed with vapour barriers and protective jacketing, rock wool insulation in metallurgical plants typically lasts 15–20 years and requires maintenance only every 3 years or so. Q: Rock wool vs ceramic fiber: which is better for metallurgy? A: Rock wool is more cost-effective and performs well up to 600–800C, making it ideal for pipes, ducts and general equipment. Ceramic fiber handles higher temperatures (up to 1260C) but is more expensive; many plants use hybrid rock wool–ceramic fiber systems for optimal balance. ### Rock Wool Insulation for Petrochemical & Refining: Applications & Benefits URL: https://www.rosetexwool.net/news/rock-wool-petrochemical-refining-insulation/ 2026-08-05 | Author: Rosetexwool Editorial | Category: industry insight Summary: Rock wool pipe insulation cuts refinery heat loss 16-60% with A1 fire rating, 600C resistance & 98% hydrophobicity. Explore applications, ROI and material comparisons. Rock wool (rockwool) has become the backbone insulation material across the petrochemical and oil refining industry. With the pipe insulation market for petrochemical plants surpassing multi-billion scale and a CAGR of 8.7%, rock wool now serves roughly 11.4% of refinery and chemical pipeline insulation demand thanks to its unmatched fire safety, high-temperature resistance and chemical stability. This guide breaks down where and why rock wool works in refineries, its economic return, and how it stacks up against aerogel, polyurethane foam, foam glass and calcium silicate. Rock Wool Applications in Petrochemical & Refining High-Temperature Pipe Insulation Rock wool pipe sections are the first-choice material for high-temperature lines in refineries and petrochemical complexes. These pipelines carry hot oil, steam and heat-transfer fluids at 450-600C, with some zones absorbing short-term 800C shocks. - Steam networks: refinery steam mains insulated with rock wool drop surface temperature from 150C to below 40C while cutting heat loss by up to 60%. - Hot oil lines: process lines transporting heat-transfer oil retain process temperature and prevent overheating of the outer jacket. - Reactor and heat-exchanger connections: keeps process temperature stable and reduces thermal energy waste. In practice, high-temperature rock wool pipe systems use a two-layer design: an inner 128 kg/m3 layer at 75 mm plus an outer 64 kg/m3 layer at 75 mm, forming a 150 mm blanket that stays stable at 600C. Low-Temperature Pipe Insulation Low-temperature rock wool sections suit cryogenic media such as LNG tanks and low-temperature process lines down to -162C. - Cooling water lines: hold low temperature and reduce cold loss. - LPG and LNG transfer lines: keep liquefied gases stable during transport. - Instrument air lines: prevent condensation and keep instruments working. A typical low-temperature system wraps rock wool with an aluminum foil or stainless-steel jacket plus a vapor barrier, forming a multi-layer "rock wool + vapor barrier + jacket" structure that blocks moisture ingress. Special Environments Rock wool performs in the harsh corners of a refinery that defeat ordinary materials. - Coastal high-salinity sites: paired with coal-tar epoxy + high-density rock wool + galvanized or FRP jacket, hydrophobicity at or above 98% delivers 15+ years of service in coastal refineries. - High-vibration zones: high-density rock wool (100+ kg/m3) with dual "banding + anchoring" fixation keeps the layer stable at pumps, valves and reactors. - Corrosive media: chemically inert rock wool resists acid/alkali and, with C2-grade foil-glass facing, holds 97%+ hydrophobicity after 1000 hours of humidity aging. Core Advantages of Rock Wool Insulation Fire Safety (A1 Non-Combustible) Rock wool meets SH/T 3010-2025 for A-class non-combustible material in petrochemical equipment and piping. - A1 non-combustible: highest fire rating, blocks flame spread. - No toxic smoke: smoke toxicity index below 0.5 versus a 5.0 limit. - High-temperature stability: stays structurally stable at 800C without softening, melting or burning. In a refinery fire scenario, rock wool buys critical evacuation time and limits loss. Heat Resistance - Continuous service: above 600C for most refinery piping. - Short-term tolerance: 800C shock for sudden high-temperature events. - Thermal stability: no powdering or shedding at high temperature; under 5% performance loss after 2000 hours at 600C, while organic foams carbonize and need steel-clad protection. Moisture & Corrosion Resistance - Hydrophobicity: 98%+ (premium products 99%), slashing water penetration. - Chemical stability: inert to acid/alkali, no corrosion to piping. - Long life: 15-20 years under good protection, far beyond organic alternatives. A fluorosilicone coating can drop surface energy below 20 mN/m for a lotus-leaf effect, stopping local water pooling and pipe corrosion. Economic Benefits of Rock Wool Lower Initial Cost - Material price: roughly 3-5x cheaper than aerogel. - Fast installation: pre-formed pipe sections wrap directly, cutting site fabrication. - No complex pretreatment: unlike calcium silicate, no high-temperature sintering needed. For a DN200 steam line, rock wool costs roughly one-third less than an aerogel composite system. Maintenance & Service Life - Service life: 15-20 years typical; 12-18 years even at 400C+ or heavy corrosion. - Low maintenance: inspect every 6 months; recoat every 10 years to extend life past 25 years. - Predictable cost: polyurethane lasts only 3-4 years and needs frequent replacement. Energy Savings - High-temperature lines: 16-60% heat-loss reduction; one 30 km steam network retrofit hit 42% measured reduction. - Low-temperature lines: 15-20% cold-loss reduction; one northern LNG project reported meaningful annual fuel savings. - Short payback: 3-5 years for refinery high-temperature piping, well below most alternatives. A 1 km DN200 steam line drops surface temperature from 150C to below 40C, cuts heat loss 60% and delivers measurable fuel savings per line. Rock Wool vs Other Insulation Materials Rock Wool vs Calcium Silicate Property | Rock Wool | Calcium Silicate | Temp limit | 600C (800C short) | 1000C+ | Fire rating | A1 | A | Density | 80-160 kg/m3 | 120-200 kg/m3 | Initial cost | Lower | Higher | Service life | 15-20 yr | 12-20 yr | Install ease | High | Medium | Calcium silicate wins only above 1000C; rock wool leads on cost and stability below 600C. How those material boundaries play out unit by unit is mapped in our guide to refinery insulation engineering by process unit. Rock Wool vs Polyurethane Foam Property | Rock Wool | PU Foam | Conductivity | 0.032-0.040 W/(m·K) | 0.022-0.027 W/(m·K) | Temp range | -200 to 650C | -50 to 150C | Fire rating | A1 | B1/B2 | Life | 15-20 yr | 3-5 yr | PU conducts slightly better but fails on fire and temperature range; it needs extra fire protection in refineries. Rock Wool vs Foam Glass Property | Rock Wool | Foam Glass | Fire rating | A1 | A1 | Density | 80-160 kg/m3 | 150+ kg/m3 | Conductivity | 0.032-0.040 | 0.060-0.064 | Cost | Lower | Higher | Install ease | High | Low | Foam glass suits deep-cryogenic and buried wet zones but is heavy, costly and brittle. Rock Wool vs Aerogel Property | Rock Wool | Aerogel | Conductivity | 0.032-0.040 | 0.013-0.018 | Initial cost | Low | 3-5x higher | Payback | 3-5 yr | 3-4.6 yr | Life | 15-20 yr | 15-20 yr | Aerogel cuts 30-40% more heat loss but at 3-5x cost; rock wool remains the economical default for most refinery piping. Challenges & Solutions Challenge | Solution | Edge water absorption | Polyurethane edge-sealing wraps the core six sides; 20+ yr life | Fiber shedding on cutting | Supplier pre-cutting and facing lamination reduce site dust | Long-term performance loss | Nano hydrophobic additive holds 97%+ after 1000 h aging | Harsh install conditions | Multi-layer "rock wool + vapor barrier + jacket" structure | Conclusion & Recommendations Rock wool delivers broad application value and clear economic return across petrochemical and refining insulation, covering -200C to 600C pipeline needs with A1 fire safety, chemical stability and high hydrophobicity. For high-temperature lines choose 120+ kg/m3 pipe sections at 50-150 mm with aluminum or galvanized jackets; for cryogenic lines use low-temp-grade rock wool with stainless or foil jackets; for coastal sites adopt the three-layer anti-corrosion composite. With a 3-5 year payback and 15-20 year life, rock wool remains the most balanced refinery insulation material as safety and energy rules tighten. For the site-wide picture across every material family on the same duties — ceramic fibre, calcium silicate, glass wool and aerogel included — our full petrochemical plant insulation guide covering every material family selects unit by unit. Related Reading - petrochemical refining insulation - power plant insulation - cryogenic LNG insulation Related products: Rockwool Insulation Blanket (Rock Wool Blanket), Rockwool Pipe Insulation for Steam Pipes, rock Wool Strips Related applications: Petrochemical FAQ: Q: Why is rock wool used for refinery pipe insulation? A: Rock wool is **A1 non-combustible**, resists up to 600C continuous (800C short-term) and is chemically inert, making it ideal for the fire-safe, high-temperature and corrosive conditions found in refineries and petrochemical plants. Q: What temperature can rock wool insulation withstand? A: Rock wool performs at **600C continuous service** and tolerates **800C short-term shocks**. Below 600C it is more cost-effective than calcium silicate or aerogel for refinery piping. Q: How much heat loss does rock wool reduce in steam lines? A: Rock wool pipe insulation cuts refinery steam-line heat loss by **16-60%**. A 30 km steam network retrofit recorded a 42% measured reduction, and a 1 km DN200 line dropped surface temperature from 150C to below 40C. Q: Is rock wool better than aerogel for petrochemical insulation? A: Aerogel insulates 30-40% better but costs **3-5x more**. For most refinery and petrochemical piping, rock wool offers the better balance of fire safety, service life and payback (3-5 years). Q: What density and thickness of rock wool for high-temperature pipes? A: For refinery high-temperature lines choose **120+ kg/m3 density** pipe sections at **50-150 mm thickness**, paired with an aluminum foil or galvanized steel jacket for stable 600C service. Q: How long does rock wool insulation last in a refinery? A: Under normal refinery conditions rock wool lasts **15-20 years**; even at 400C+ or heavy corrosion it reaches 12-18 years. Inspect every 6 months and recoat every 10 years to extend life past 25 years. ### rock wool in the Power Industry: Fire-Safe, High-Temperature Insulation URL: https://www.rosetexwool.net/news/rock-wool-applications-in-power-industry/ 2026-08-02 | Author: Rosetexwool Editorial | Category: industry insight Summary: A practical guide to rock wool in power systems — A1 fire safety, 600–700°C stability and 20+ year life for boilers, steam piping, substations, nuclear and offshore wind. rock wool in the Power Industry: Fire-Safe, High-Temperature Insulation rock wool (also called rockwool) has become the default A1 non-combustible insulation for the power sector. It operates continuously at 600–700°C, resists fire for 3+ hours, and serves 20+ years on boilers, steam piping, substations, nuclear facilities and offshore wind — far outlasting glass wool and rubber-plastic alternatives. This guide explains where rock wool is used in power systems and why engineers specify it. 1. Why the Power Industry Specifies Rock Wool 1.1 Key Properties - A1 non-combustible: inorganic basalt fibers do not burn, melt or release toxic smoke; oxygen index ≥50, smoke toxicity class t0, fire resistance limit ≥3 hours. - High-temperature stability: long-term service at 600–700°C and short-term tolerance above 1000°C — far beyond glass wool (≈260°C) and rubber-plastic (≈150°C). - Thermal efficiency: thermal conductivity 0.034–0.040 W/(m·K) at 25°C, stable because the material is inorganic and does not age. - Service life 20+ years: versus 8–10 years for glass wool and 5–8 years for rubber-plastic, with near-zero maintenance cost. - Chemical stability: chloride ≤10 mg/kg protects austenitic stainless steel from stress corrosion; water repellency ≥98.5%. - Mechanical strength: compressive strength ≥80 kPa, tensile strength ≥10 kPa; resists vibration on running equipment. 2. Core Application Scenarios 2.1 Boiler and furnace insulation Power boilers run at 400–800°C on water-wall, superheater and economizer zones. High-density rock wool board (≥120 kg/m³, 100–150 mm) with stainless pins and metal cladding keeps outer-surface temperature at 40–50°C and cuts heat loss. A 660 MW retrofit lowered boiler heat loss from 8% to 5% and paid back in ~1.5 years. 2.2 Steam and thermal piping High-temperature steam lines (>400°C) use a composite of rock wool pipe shell (≥120 kg/m³, ≥50 mm) plus metal or galvanized cladding. Medium- and low-temperature lines use single-layer shells. Rock wool keeps conductivity change under 5% at high temperature, while rubber-plastic can exceed 20%. 2.3 Substations and power equipment Main transformers are wrapped in rock wool (50–80 mm, ≥100 kg/m³) to lower operating temperature and extend life. Prefabricated substations use rock wool as an A-class fire barrier (≥120 kg/m³, 3-hour rating). Cable trays and cable trenches use rock wool fire boards (≥50 mm) to stop fire spread per GB/T 25975. 2.4 Nuclear power facilities Nuclear islands and conventional islands use rock wool pipe shells (≥120 kg/m³, 80–120 mm) on main steam lines above 600°C. Valves and flanges use rock wool blanket (≥100 kg/m³). Low-chloride grades (Cl⁻ ≤10 mg/kg) prevent stress corrosion of austenitic stainless steel. Cable trenches use ≥50 mm fire boards for compartmentation. 2.5 Offshore wind Offshore platforms face salt spray and high humidity. Rock wool pipe shells (≥110 kg/m³, ≥50 mm) with galvanized or epoxy-coated cladding protect steam lines for 15+ years. Transformers, cable trays and nacelle equipment use hydrophobic rock wool (repellency ≥99%) to resist corrosion. 2.6 Energy storage stations With storage booming, rock wool fire boards (≥50 mm) compartment battery cabins and cable trenches to an A-class standard, preventing thermal-runaway propagation. Equipment is also insulated to improve efficiency. 3. Rock Wool vs Glass Wool vs Rubber-Plastic Property | Rock wool | Glass wool | Rubber-plastic | Max service temp | 600–700°C | 250–300°C | 110–150°C | Fire rating | A1 non-combustible | A non-combustible | B1 difficult-to-ignite | Oxygen index | ≥50 | >30 | 32–35 | Fire resistance limit | ≥3 h | 0.5–1 h | 0.5 h | Service life | 20+ years | 8–10 years | 5–8 years | Thermal conductivity (25°C) | 0.034–0.040 W/(m·K) | 0.030–0.034 W/(m·K) | 0.038–0.043 W/(m·K) | 4. Lifecycle Cost Advantage Although rock wool's initial cost is slightly higher, its 20-year near-zero maintenance and high energy savings dominate total cost. On a 1000 m steam line, 10-year savings reach 6 million yuan versus 4.5 million for glass wool and 3 million for rubber-plastic; payback is 1.5–2 years. One 500 kV substation cut heating runtime 30% and saved ~100k yuan/year in electricity after switching to rock wool pipe. 5. Selection and Installation Tips - Match density to temperature: ≥120 kg/m³ for high-temperature zones; ≥140 kg/m³ for boiler furnaces. - Use low-chloride grade for austenitic stainless steel (nuclear, superheater). - Use hydrophobic grade (≥99%) for offshore and buried networks. - Verify test reports for thermal conductivity, fire rating and acidity coefficient (≥1.8). - Seal joints with fire sealant and fix with pins (300×300 mm staggered) to avoid cold bridges. 6. Standards and Market Relevant codes include GB 50126 (industrial equipment insulation), GB 50016 (building fire), and DL/T 5714-2024 / DL/T 5713-2024 (power equipment thermal insulation). The domestic pipeline-insulation market passed 180 billion yuan in 2025, with inorganic materials like rock wool pipe taking over 70% — a clear signal of continued growth in power-sector adoption. Related Reading - power plant insulation - nuclear power insulation - CSP molten-salt insulation Related products: Rockwool Insulation Blanket (Rock Wool Blanket), Rockwool Insulation Slabs — Rock Wool Board, Rockwool Pipe Insulation for Steam Pipes Related applications: Power Generation FAQ: Q: Is rock wool suitable for high-temperature power equipment? A: Yes. Rock wool runs continuously at 600–700°C and tolerates short-term temperatures above 1000°C, with a fire-resistance limit of 3+ hours (A1 non-combustible, oxygen index ≥50). That makes it the standard choice for boilers, superheaters, steam piping and nuclear main-steam lines — far beyond glass wool (≈260°C) and rubber-plastic (≈150°C). Q: What rock wool products are used in substations and energy storage stations? A: Substations use rock wool blanket or board to wrap transformers (50–80 mm, ≥100 kg/m³) and rock wool fire boards (≥50 mm) in cable trays and trenches to stop fire spread. Energy storage stations use the same ≥50 mm fire boards to compartment battery cabins to an A-class standard and prevent thermal-runaway propagation. Q: Why choose rock wool over glass wool or rubber-plastic in power plants? A: Rock wool beats both on temperature, fire and life: 600–700°C service versus 260°C/150°C, A1 versus B1, and 20+ years versus 8–10/5–8 years. Its near-zero maintenance and 1.5–2 year payback give the lowest 10-year total cost despite a higher upfront price. ### rock wool in the Building & Construction Industry: Fire-Safe, Thermal & Acoustic Insulation URL: https://www.rosetexwool.net/news/rock-wool-applications-in-construction/ 2026-07-31 | Author: Rosetexwool Editorial | Category: industry insight Summary: A complete guide to rock wool in construction — A1 non-combustible fire safety, 0.034–0.042 W/(m·K) thermal insulation and acoustic performance across walls, roofs and partitions. rock wool in the Building & Construction Industry: Fire-Safe, Thermal & Acoustic Insulation rock wool (also called rockwool) is an inorganic, mineral-based insulation material made from natural basalt, diabase and dolomite melted above 1450°C and spun into ultra-fine fibers. With its exceptional fire resistance and outstanding thermal performance, rock wool has become an indispensable material in modern construction. As national building energy-efficiency standards tighten and the "dual-carbon" strategy advances, rock wool is evolving from a conventional insulating material into high-performance, multi-functional, system-level solutions. This article examines rock wool's properties, product forms, construction applications, core advantages, installation best practices and future trends to give building professionals a practical reference. 1. rock wool Properties and Product Forms 1.1 Key Properties A1 non-combustible: Rock wool fibers are inorganic silicate, inherently non-combustible. They emit no toxic smoke at high temperature and effectively block fire spread, making rock wool an ideal material for building fire-protection systems. High thermal efficiency: Fine, evenly distributed fibers and a porous structure trap air and reduce heat transfer. Thermal conductivity typically falls between 0.034 and 0.042 W/(m·K). Excellent acoustic performance: The open porous structure absorbs and dampens sound waves with a high sound-absorption coefficient — ideal for public spaces with strict noise requirements. Stable hydrophobicity: Advanced water-repellent treatment keeps volumetric and mass moisture uptake low (mass moisture ≤1%, water repellency ≥98%), resisting vapor penetration and preventing performance loss from dampness. Chemically stable and healthy: Made from inorganic stone, with no CFCs, asbestos or formaldehyde — safe for occupants and compliant with green-building standards. High compressive and tensile strength: High-density boards reach compressive strength ≥40 kPa and perpendicular tensile strength ≥15 kPa, with dimensional stability ≤1.0% relative change. Lightweight and workable: Density typically 60–200 kg/m³; easy to cut and drill on site for complex geometries. 1.2 Main Product Forms rock wool board: Flat slab, density 60–200 kg/m³, good compression resistance and easy cutting. Used for external wall insulation, fire barriers, roof insulation and load-bearing applications. rock wool blanket: Flexible, density 40–120 kg/m³, can be rolled. Suited to irregular surfaces and pipe insulation such as HVAC ductwork and light-gauge steel stud partitions. Rock wool sandwich panel: Rock wool core laminated with metal facings, density ≥120 kg/m³, excellent compression and airtightness. Used for fast-erected steel plants, cold stores and clean rooms. rock wool pipe: Tubular, higher density, mainly for industrial pipe insulation (steam, hot water, oil and gas lines) with good wrapping and sealing. 2. Primary Construction Applications 2.1 Exterior Walls External thermal insulation systems (ETICS): Rock wool board is the core material for ETICS, especially high-rise and public buildings. Under the "Code for Fire Protection Design of Buildings," when a building exceeds 50 m or is a crowded-place occupancy, the external insulation must reach Class A fire rating — which rock wool fully satisfies. Typical build-up: substrate treatment → adhesive → board fixing → mechanical anchors → base coat → alkali-resistant mesh → finish coat. 2.2 Roofs Flat and pitched roofs: Rock wool board as a roof insulation layer significantly cuts heat transfer and raises thermal resistance, lowering heating and cooling energy use. Its light weight minimizes roof load. Metal roof sandwich panels: Rock wool-core panels deliver waterproofing, airtightness and insulation for fast-built industrial plants and warehouses. PV roof systems: New-generation rock wool decorative-insulation panels integrate a photovoltaic layer, achieving "insulate–generate–decorate" in one, boosting building energy efficiency. 2.3 Interiors Light-gauge steel stud partitions: Rock wool blanket, with its flexibility and acoustic properties, fills stud walls to separate spaces and improve room acoustics. Ceiling systems: Rock wool board in suspended ceilings absorbs sound energy, reduces noise transmission and adds thermal insulation. Fire compartmentation: Rock wool forms fire walls, fire doors and elevator-shaft fire stops, preventing internal fire spread and protecting evacuation. 2.4 Industrial and Special Environments Industrial pipe insulation: Rock wool pipe and blanket insulate equipment and piping in petrochemical, power and chemical plants, with strong high-temperature resistance. Steel-structure fire protection: Rock wool composite boards clad steel beams and columns, raising fire-resistance ratings to meet code. Marine and transport: Hydrophobic rock wool board insulates and fire-divides ships and rolling stock to stringent marine and transit specs. Humid environments: Hydrophobic rock wool (water uptake ≤1%) avoids damp-driven performance loss and wall mold in rainy or humid regions. 3. Rock Wool vs Other Insulation Materials 3.1 Fire Safety Higher fire class: Rock wool is A1 non-combustible, whereas common organics such as EPS, XPS and PU are mostly Class B combustible. Under heat, B-class materials melt, drip or release toxic smoke; rock wool does not. Higher fire-resistance rating: Quality rock wool board exceeds 2 hours; PU-edged rock wool composite panels can reach 4 hours of fire resistance. Inherent mechanism: Rock wool's fire performance comes from its inorganic silicate fibers, not additives, so it stays stable over time. 3.2 Thermal Performance Low conductivity: 0.034–0.042 W/(m·K), comparable to some high-performance organics and decreasing with density, meeting varied code levels. Long-term stability: As an inorganic material, rock wool suffers no thermal decomposition or aging-driven performance loss. Thermal-bridge阻断: Its dense, uniform fiber structure blocks thermal bridges and reduces heat loss. 3.3 Environmental and Health Non-toxic: No asbestos, formaldehyde or CFCs; non-corrosive; does not harbor mold or bacteria. Recyclable: 100% recyclable, listed in green-building recommendation catalogs. Low-carbon production: New processes cut manufacturing emissions, supporting dual-carbon goals. 3.4 Buildability and Function Easy installation: Uniform boards cut and drill readily, speeding work. Multi-function integration: Combines insulation with fire, acoustic and decorative functions, reducing system complexity. Corrosion resistance: Non-corrosive to steel, aluminum and copper, extending structural life. Economics: Higher upfront cost than some organics, but lower lifecycle maintenance yields strong overall value. System solutions: Suppliers offer one-stop selection, design, production, logistics and installation. 4. Installation Notes and Future Trends 4.1 Installation Notes Conditions: Ambient temperature ≥5°C in winter; avoid direct summer sun (water-cure above 25°C). Substrate must be dry, oil-free, rust-free; protect board from rain for 24 h after fixing. No work in wind above level 5 or in rain. Workmanship: Adhesive coverage ≥50%; anchors ≥6 per m² with embedment ≥25 mm; tight board joints to avoid thermal bridges, sealed with weatherproof sealant; build insulation, base coat and finish in sequence. Quality control: Verify board dimensions (length ±10 mm, width ±5 mm, thickness ±3 mm), flatness and appearance per GB/T 25975-2010. 4.2 Future Trends Policy-driven growth: China's dual-carbon push and rising efficiency codes (80% for new public buildings, 75% for residential by 2026) expand demand; many regions mandate Class A fire insulation above 50 m, strengthening rock wool's position. Lightweight tech: New decorative-insulation panels use flexible mortar bases, cutting ~6 kg per panel and reducing wall load. Renewable tech: Recyclable binders (e.g., PVC–epoxy composites) solve traditional sodium-silicate waste-loosening problems. Functional integration: High-end products embed PV layers for "insulate–generate–decorate" triple function. Smart manufacturing: Industry 4.0 lines improve consistency and installation efficiency. 5. Conclusion and Recommendations Rock wool — with its fire safety, stable thermal performance, acoustic quality and healthy, eco-friendly profile — is now essential across exterior walls, roofs, interior partitions and ceilings. Its A1 fire rating is irreplaceable in high-rise and public buildings. Versus organic insulation, rock wool leads on fire safety, long-term stability, health and multi-function integration; despite higher upfront cost, its lifecycle value is compelling. For designers and contractors: - Choose fire class by building type and height; prioritize A1 materials like rock wool for high-rise and public buildings. - Match density and thickness to energy code and climate for balanced insulation and fire performance. - Use multi-function products (acoustic, decorative, PV-integrated) to cut system complexity. - Follow national standards and specifications strictly for durable, high-performance systems. - Evaluate whole-lifecycle cost, not just price. As dual-carbon and efficiency standards advance, rock wool use will widen. Future products trend toward lightweight, renewable and functionally integrated, with smart manufacturing raising quality and efficiency. Professionals should watch these innovations to maximize rock wool's value in safe, comfortable, green buildings. Related Reading - rock wool building insulation - green building insulation - fire-safe building insulation Related products: Rockwool Insulation Slabs — Rock Wool Board, Rockwool Insulation Blanket (Rock Wool Blanket), Rockwool Pipe Insulation for Steam Pipes, rock Wool Strips, rock Wool Acoustic Panels, rock wool Wired Insulation Blanket, Rock Wool Blanket with Glass Fiber Mesh Related applications: Traffic & Fire Protection FAQ: Q: Is rock wool fire resistant? A: Yes. Rock wool is A1 non-combustible — it does not burn, melt or release toxic smoke, and quality boards deliver 2+ hours of fire resistance (up to 4 hours for PU-edged composites). It is the preferred Class A insulation for buildings above 50 m and crowded public occupancies. Q: What is the thermal conductivity of rock wool? A: Rock wool typically has a thermal conductivity of 0.034–0.042 W/(m·K). It decreases with density and stays stable over the product's life because the material is inorganic and does not degrade. Q: Where is rock wool used in buildings? A: Rock wool is used in external wall insulation systems (ETICS), flat and pitched roofs, light-gauge steel stud partitions, suspended ceilings, fire compartmentation (walls, doors, shafts), and industrial pipe and steel-structure fire protection. ### Calcium Silicate in Cement Industry: Applications, Benefits & Technical Guide URL: https://www.rosetexwool.net/news/calcium-silicate-insulation-cement-industry-guide/ 2026-07-31 | Author: Rosetexwool Editorial | Category: industry insight Summary: Calcium silicate insulation cuts cement kiln heat loss 25% and lowers shell temp 30-40C. Explore board, fiber & composite applications for preheaters, calciners and kiln seals. Calcium silicate has become an indispensable refractory insulation material in the cement industry, where rotary kilns reach 1450C during clinker formation. Backed by low thermal conductivity (0.035-0.065 W/(m·K)), A1 fire rating and service temperatures up to 1050C, calcium silicate boards, fiber composites and engineered composites now replace traditional high-energy insulation across preheaters, calciners, kiln seals and tertiary air ducts — cutting shell heat loss by over 25% and reducing coal consumption by 0.3-0.5 kg per tonne of clinker. Calcium Silicate Refractory: Properties & Classification Calcium silicate refractories are inorganic materials formed through hydrothermal reactions that generate tobermorite (180C) and xonotlite (215C) crystal structures. Based on form and application, they fall into three categories used throughout modern cement plants. 1. Calcium Silicate Board The most widely used form in cement plants. The HCS-20 grade is the mainstream product for high-temperature kiln zones, combining high temperature resistance, strength and low conductivity. Key specifications: - Temperature resistance: continuous service up to 1050C, short-term peak 1200C - Thermal conductivity: 0.035-0.065 W/(m·K) at 100C, rising gradually with temperature without sharp increase - Mechanical strength: compressive strength >=0.55 MPa, flexural strength >=0.33 MPa, excellent impact resistance - Dimensional stability: linear shrinkage <=2% after 3h at 1000C, stable under long-term high temperature - Density range: 200-450 kg/m³, available in low (1.0-1.2), medium (1.2-1.4) and high (1.4-1.5 g/cm³) density grades 2. Calcium Silicate Fiber Composites Used for high-temperature sealing and flexible insulation, primarily in kiln head and tail seal assemblies paired with heat-resistant steel lamella to form an integrated wear-resistant, insulating, anti-corrosion sealing system. Specifications: - Temperature resistance: 800-1000C, special grades up to 1200C - Thermal conductivity: 0.045-0.050 W/(m·K), lower than standard ceramic fiber - Tensile strength:>=500 N (10mm packing), resists fracture under high temperature - Sealing performance: leakage rate <=5 mL/min·m at 800C, down to <=3 mL in specific conditions - Thermal shock resistance: withstands frequent kiln start-stop cycles 3. Calcium Silicate-Based Composites Next-generation materials combining calcium silicate with solid waste or mineral additives to meet specialized kiln demands while cutting natural resource consumption and carbon emissions: - Solid-waste based: incorporates fly ash and slag at 73%+, thermal conductivity as low as 0.042 W/(m·K) - High-strength refractory: C2S-C3S composite system, compressive strength 165-170 MPa for high-load kiln zones - Fiber-reinforced: calcium aluminate fiber board, flexural strength >=9 MPa, combining strength and insulation For the material behind those classifications — how calcium silicate insulation is made, what the two temperature grades mean, and the full property table — see our calcium silicate insulation grades and properties guide. Key Application Areas in Cement Plants Preheater System Preheaters operate at 900-1250C and face alkali salt penetration, thermal shock and abrasion. Calcium silicate boards serve as backup insulation in: - Five-stage cyclone tubes — paired with high-alumina brick to cut heat loss and boost heat exchange - Meal pipes — external wall insulation preventing heat dissipation - Riser ducts (especially stage 3-2) — isolation to reduce shell radiation - C5 meal pipe and slope — combined with anti-coating castable in the highest coating-risk zone Result: shell surface temperature drops 30-40C and heat loss falls by over 25%, measurably improving thermal exchange efficiency. Calciner System The calciner runs at 1000-1300C under corrosive gas and heavy dust loads. Calcium silicate boards pair with low-cement high-alumina castable in: - Calciner inner lining — improved insulation and extended service life - Gooseneck pipe — external insulation reducing heat loss - Kiln tail gas chamber — paired with refractory brick to stabilize combustion Properly applied calcium silicate in the calciner improves thermal regime and lowers coal consumption by 0.3-0.5 kg per tonne of clinker. Kiln Head & Tail Sealing Kiln head and tail are the highest air-leakage zones. Traditional fish-scale seals suffer short service life and poor sealing. Modern solutions using calcium silicate fiber composites include: - Dual-flexible seal: fiber composite as intermediate insulation layer with heat-resistant steel lamella - Three-layer seal: wear layer + calcium silicate insulation + protection layer, service life 2-3+ years - Kiln hood seal: calcium silicate board preventing hot gas escape The impact is significant: air leakage drops from the traditional 8%-15% down to 0.5%-1%, directly improving combustion efficiency and reducing both coal and power consumption. Tertiary Air Duct Connecting the kiln head to the preheater, the tertiary air duct carries high-temperature, high-velocity gas that demands excellent abrasion and temperature resistance. Calcium silicate boards pair with high-strength alkali-resistant brick in straight pipe and wall sections to improve insulation and structural stability. Why Cement Plants Choose Calcium Silicate - Energy savings: low thermal conductivity (0.035-0.065 W/(m·K)) cuts heat loss and fuel use - Long service life: <=2% shrinkage at 1000C maintains performance over years of continuous operation - Structural protection: shields kiln shell and steelwork from thermal stress and deformation - Asbestos-free and safe: 100% non-asbestos, non-toxic, sulfur- and chlorine-free, compliant with international standards - Easy installation: lightweight, cut to shape with standard tools, available in board and block formats Conclusion Calcium silicate insulation has become a proven backbone of cement plant thermal systems. From preheater cyclones to kiln seals, its combination of low conductivity, high-temperature stability and mechanical strength delivers measurable gains in energy efficiency, equipment life and emissions reduction. With over 40 years of manufacturing experience since 1982 and ISO 9001 certification, Rosetexwool supplies calcium silicate boards, blocks and fiber composites engineered for the demanding conditions of modern cement production. Contact our technical team for specification and pricing. Related Reading - cement kiln insulation - steel furnace insulation Related products: High Density Calcium Silicate Board Related applications: Cement FAQ: Q: What temperature can calcium silicate board withstand in cement kilns? A: Calcium silicate boards for cement plants offer continuous service up to 1050C with short-term peak tolerance to 1200C. The HCS-20 grade is the mainstream choice for high-temperature kiln zones, maintaining dimensional stability with <=2% linear shrinkage after 3 hours at 1000C. Q: How much energy does calcium silicate insulation save in cement plants? A: In preheater systems, calcium silicate board insulation reduces shell surface temperature by 30-40C and cuts heat loss by over 25%. In calciner applications, coal consumption drops by 0.3-0.5 kg per tonne of clinker. Modern three-layer kiln seals using calcium silicate fiber composites lower air leakage from 8-15% down to 0.5-1%. Q: Where is calcium silicate used in a cement plant? A: Calcium silicate is used across the cement plant thermal system: preheater cyclones and meal pipes, calciner inner lining and gooseneck, kiln head and tail sealing assemblies, tertiary air ducts, and clinker cooler walls. It serves as backup insulation behind the primary refractory lining to maintain safe shell temperatures. ### Petrochemical Reformer Furnace Reline — A Complete Ceramic Fiber Module Solution URL: https://www.rosetexwool.net/news/petrochemical-reformer-furnace-reline-case-study/ 2025-11-15 | Author: Rosetexwool Engineering Team | Category: case study Summary: How Rosetexwool relined a Middle East reformer furnace in 12 days with 1,200 ceramic fiber modules, achieving sub-65°C shell temps. Project Overview In Q3 2025, Rosetexwool completed a major reformer furnace reline project for a petrochemical plant in the Middle East. The facility operates a continuous catalytic reformer (CCR) producing high-octane gasoline components, with design temperatures reaching 1260 °C in the radiant section. The existing lining had suffered thermal degradation after 8 years of service, resulting in excessive shell temperatures and energy loss. "Rosetexwool's engineering support during material selection was exceptional. Their team was on-site for installation supervision and the furnace has performed above expectation since restart." — Senior Project Engineer, Client Challenge The client faced three key constraints: - Thermal cycling severity — the reformer undergoes 6–8 planned shutdowns per year, requiring insulation that withstands repeated thermal shock without spalling. - Shell temperature target — the plant's energy management program mandated shell temperatures below 65 °C at any point, with an ambient reference of 25 °C. - Installation window — a tight 14-day turnaround window during the scheduled plant turnaround, with 24-hour shift work required. Solution Radiant Section — Ceramic Fiber Module System We supplied 1430 °C-grade ceramic fiber modules (300×300×300mm, 210 kg/m³ density) with SS310 stainless steel anchoring for the radiant wall and arch. The modules were factory pre-compressed to 35% compression for simplified field installation. A 25mm ceramic fiber blanket backing layer (128 kg/m³) was installed behind modules to achieve the target cold-face temperature. Design Temperature 1260 °C Radiant section operating Shell Temperature < 65 °C Post-installation measured Module Density 210 kg/m³ Optimal for radiant duty Installation Time 12 days vs 14-day target Convection Section & Breaching For the convection section and hot gas breaching (operating at 600-900 °C), we supplied calcium silicate pipe sections (100mm thickness, 245 kg/m³ density) for all steam and transfer lines, and rock wool blankets (100kg/m³, 50mm thickness) with aluminium cladding for large-diameter ducting. Material | Location | Spec | Qty | Ceramic Fiber Module | Radiant wall & arch | 1430 °C, 300×300×300mm, 210kg/m³ | 1,200 pcs | Ceramic Fiber Blanket | Backup layer | 1430 °C, 25mm, 128kg/m³ | 380 m² | Calcium Silicate Pipe | Steam & transfer lines | 100mm, 245kg/m³ | 620 m | Rock Wool Blanket | Hot gas ducting | 50mm, 100kg/m³ | 480 m² | Installation & Quality Control Our technical team provided on-site supervision for the full 12-day installation , ensuring proper module anchoring, compression release, and joint sealing. Key quality metrics verified during installation: - Anchor weld integrity — 100% visual inspection + 10% random dye penetrant testing - Module compression release — measured post-release expansion to ensure zero-gap joints - Blanket backing layer overlap — minimum 100mm overlap at all joints - Shell temperature survey — thermographic scan of full radiant shell 48 hours after restart Results - Shell temperatures reduced by an average of 28 °C compared to the previous lining, with all points under the 65 °C target. - Installation completed in 12 days — two days ahead of the 14-day turnaround window, enabling earlier restart. - Estimated fuel savings of approximately 3.5% based on reduced heat loss through the furnace shell, per the client's energy balance model. - Zero non-conformance reports (NCRs) during the entire quality inspection process. This case study demonstrates Rosetexwool's capability to deliver complete insulation systems for critical high-temperature petrochemical applications, from material selection through on-site installation support. Why the CCR reactor behind this furnace drove every one of those material decisions — including the cold-wall alternative — is explained in our guide to hot-wall and cold-wall reformer insulation. Related Reading This reformer reline came down to three material decisions we've since documented in depth: - Ceramic Fiber vs Rock Wool for Furnace Linings — why 1430 °C ceramic fiber modules beat rock wool in the radiant section. - Best Heat-Resistant Materials for Furnace (2026 Guide) — how to grade insulation by furnace operating temperature. - Calcium Silicate vs Ceramic Fiber Board — how these two high-temperature materials compare across furnace applications. Explore more on our Petrochemical Insulation application page. Related products: Calcium Silicate Pipe, Refractory Ceramic Fiber Blanket — Ceramic Fiber Blanket Insulation, Ceramic Fiber Modules, Calcium Silicate Insulation Board, Rockwool Insulation Slabs — Rock Wool Board Related applications: Petrochemical, Iron & Steel FAQ: Q: What ceramic fiber grade is recommended for reformer furnace radiant sections? A: For reformer radiant sections operating at 1100-1260 °C, we recommend 1430 °C-grade ceramic fiber modules (210 kg/m³) with a 25mm 1430 °C-grade blanket backing layer. This combination provides the thermal shock resistance required for frequent cycling and achieves shell temperatures below 65 °C. For less severe service (below 1150 °C), 1400 °C-grade modules may be sufficient. Q: How long does a typical reformer furnace reline take? A: A complete radiant section reline typically requires 10-14 days with 24-hour shift work, depending on furnace size and access. Pre-planning is critical — we recommend ordering materials at least 6-8 weeks before the turnaround, confirming anchor patterns with the engineering team, and having installation tools pre-staged. Rosetexwool can provide on-site supervision to ensure quality and schedule adherence. Q: Can you provide on-site installation supervision? A: Yes. Our technical team provides on-site supervision for large-scale installation projects including furnace relines, boiler linings, and kiln insulation. We cover anchor welding inspection, module compression release verification, joint sealing, and final thermographic survey. Supervision can be arranged as part of the material supply contract. ### Glass Wool Insulation Board: Rigid Board Selection & Spec URL: https://www.rosetexwool.net/news/glass-wool-insulation-board-rigid-board-selection-spec/ Author: Rosetexwool Editorial | Category: industry insight Summary: Spec-side guide to glass wool rigid insulation board: density classes 24–100 kg/m³, lambda, compressive, A1 fire, facings, tolerances, and side-by-side comparison with rock wool board. Where Rigid Board Comes From — and Why Spec Matters Glass wool rigid board is the same melt-spun glass fibre used to make blanket and roll, but bonded into a flat, self-supporting panel. The form factor is what changes the specification logic. A blanket drapes and conforms; a board holds its shape inside a framed cavity, takes fixing pressure without slumping, and gives a clean surface for a bonded facing. Every spec on a data sheet — density, lambda, compressive strength, water repellency, acoustic — has to be read against that single fact: the panel is rigid and the joint is fixed. A spec sheet for glass wool board is not the same as a spec sheet for blanket, and it is definitely not interchangeable with rock wool board at the same density. Two boards of the same nominal density can perform very differently depending on how the fibre is formed, how the binder is cured, and which facing is bonded to the surface. Choosing by density alone is the most common error we see in purchasing documents; this guide explains which parameter to read for which decision. The full material grade range is listed on our glass wool board product page. For applications where board sits in a frame to deliver thermal and acoustic performance together, see our glass wool board applications guide, which covers the application side in detail. The present guide is the spec and selection counterpart — density, lambda, strength, fire, facing and tolerances. Density Classes and What Each One Buys You Density is the master variable on a glass wool board data sheet, because almost every other spec flows from it. The practical bands used by manufacturers worldwide are 24, 32, 48, 64, 80 and 100 kg/m³, occasionally extending to 120 kg/m³ for acoustic grades. Going up in density raises compressive strength, improves acoustic absorption above 500 Hz, and gives the board the body needed to carry a foil or tissue facing without bowing. Going down in density drops weight, lowers material cost, and improves thermal performance at 25 °C within a useful window. Beyond roughly 80 kg/m³, however, lambda at 25 °C starts to drift upward again because the fibre packing squeezes the air cavities that drive the insulation, which is why the most efficient building densities sit in the 24–48 kg/m³ band rather than at the high end. The density band itself is not the spec — what matters is the spec values inside the band. A 48 kg/m³ board from one supplier and a 48 kg/m³ board from another can differ in lambda by 0.005 W/(m·K) and in compressive strength by 20 kPa. Density is a sorting parameter; lambda and compressive strength are the spec. Density band | Typical role | Where it tends to be specified | 24–32 kg/m³ | Light fills, friction-fit cavities, partition infill | Internal walls, light ducts | 32–48 kg/m³ | General wall insulation, steel-structure envelope | Curtain-wall spandrels, sandwich panels | 48–64 kg/m³ | Structural envelope, mixed thermal/acoustic | Metal deck roofs, facade cassettes | 64–96 kg/m³ | High-temperature equipment, hot-face service | Industrial casings, ducts carrying warm air | 80–110 kg/m³ | Acoustic ceilings, studio treatments | Studios, auditoria, plant rooms | ≥ 100 kg/m³ | Special-duty acoustic, load-bearing boards | Plant-room ceilings, trafficable decks | Four Spec Parameters That Decide Suitability Thermal conductivity. At 25 °C, glass wool board lambda typically lands between 0.032 and 0.045 W/(m·K) depending on density. The lowest lambda values sit in the 24–48 kg/m³ window; above that, lambda at 25 °C rises slightly. At 70 °C — the temperature at which hot-side service behaviour starts to deviate from cold-side behaviour — lambda lands at 0.039 to 0.042 W/(m·K) for the same products. Ask for the lambda curve in the data sheet, not just a single number; the same board is rarely as efficient at 200 °C as it is at 25 °C. Compressive strength. This is the spec that determines whether a board can be walked on, fitted between studs without slumping, or carry a bonded facing without bowing. The standard test is 10 % deformation in the through-thickness direction. Practical bands: 24 kg/m³ grades typically reach 10–30 kPa, 48 kg/m³ grades 50–80 kPa, 64 kg/m³ grades 80–120 kPa, 96 kg/m³ grades 120–200 kPa, and ≥ 100 kg/m³ grades exceed 200 kPa. Below 24 kg/m³ the board is not a board in any meaningful sense and should be treated as a soft product. Acoustic absorption. Glass wool absorbs through its open fibre structure, and absorption rises as density increases up to a peak around 80–100 kg/m³ at low frequencies and around 48–64 kg/m³ at mid-to-high frequencies. The metric specifiers should track is NRC — the Noise Reduction Coefficient, an arithmetic average of absorption at 250, 500, 1,000 and 2,000 Hz, rounded to the nearest 0.05. A 50 mm board at 48 kg/m³ reaches NRC 0.85–0.95. A 50 mm board at 80 kg/m³ reaches NRC 0.95–1.00. Above 100 mm thickness, NRC gains are marginal; below 25 mm, NRC drops sharply. Water repellency and acoustic-facing behaviour. Two parameters that are easy to miss but matter in service. Hydrophobic treatment to ≥ 98 % water repellency is required for any board exposed to condensation, rain ingress, or outdoor service. Open or tissue facings preserve acoustic absorption; sealed foil facings block it. A board that meets both A1 non-combustibility and ≥ 98 % water repellency is the baseline specification for most external building applications. Glass Wool vs Rock Wool Board — Selection Matrix Glass wool and rock wool board overlap on most building applications but diverge sharply where temperature and structural load rise. The reading is straightforward: glass wool wins on weight, lambda at 25 °C, acoustic absorption and cost; rock wool wins on temperature limit, compressive strength and fire behaviour under load. Spec | Glass wool board | Rock wool board | Lambda at 25 °C | 0.032–0.045 W/(m·K) | 0.040–0.048 W/(m·K) | Compressive strength (10 % deformation) | Up to ~200 kPa at 100 kg/m³ | Up to ~300 kPa or more at 100 kg/m³ | Maximum service temperature | 250 °C standard; 538 °C high-temperature grades | 600–1,100 °C depending on grade | Acoustic absorption (NRC, 50 mm) | Up to 0.95–1.00 (peak at 80–110 kg/m³) | Up to 0.70 typical | Fire classification (unfaced) | A1 non-combustible | A1 non-combustible | Density range | 24–120 kg/m³ | 60–200 kg/m³ | Weight advantage at same thickness | Lighter (lower density bands cover more cases) | Heavier for the same lambda | Cost | Generally lower | Generally higher | Three rules follow. First, rock wool stops at 800 °C service and runs higher than glass wool in the 800–1,100 °C band; once that band is reached, glass wool is no longer an option. Second, in the 250–600 °C band, high-temperature glass wool and rock wool compete on a cost/spec basis — read the bid documents carefully because both materials appear in the spec. Third, in any acoustic specification, glass wool outperforms rock wool at the same thickness, which is why studios and concert halls use glass wool behind perforated panels. For a complete comparison of the two material families across applications, see our industrial pipe insulation materials overview, which puts both side by side in real installations. On fire performance specifically — what A1 means in practice and how unfaced and faced products differ — see our dedicated note is glass wool fireproof. Where the decision reaches beyond board — temperature ceiling, fire barrier duty or acoustic target — our full glass wool vs rock wool form-by-form comparison covers all seven differences. If the question is vocabulary rather than material — what separates board from panel, tile and sheet across all five insulation families — our insulation board and panel forms guide fixes each term before you send the enquiry. Temperature Limits, Service vs Peak The temperature spec on a glass wool board data sheet has two readings, and conflating them is the second most common spec error. Maximum continuous service temperature is the temperature at which the board can sit indefinitely without fibre degradation, binder breakdown or excessive linear shrinkage. Peak or excursion temperature is a short-duration ceiling — minutes rather than hours. Most glass wool boards run 250 °C continuous on the standard grade and 538 °C continuous on the high-temperature grade, with peak temperatures 100–200 °C above those figures for short exposures. Where the bid documents ask for "538 °C glass wool", clarify whether that is continuous or peak before comparing prices. Above roughly 538 °C, glass wool is no longer the right answer; polycrystalline wool fibre modules and similar high-temperature modules cover the 1,260–1,700 °C band, typically in combination with a refractory back-up. A practical procurement rule: if the equipment can be touched for maintenance without thermal protection beyond gloves, glass wool board at 250 °C continuous is the wrong choice and high-temperature glass wool or a layered lining is needed. The selection between the two depends on operating hours, temperature cycling and the binder chemistry on the data sheet — read the data sheet, do not infer it from a product brochure. Facings — What Each One Does A facing on a glass wool board is not decorative; it changes how the board behaves in service. The common facings and what they do are: - Unfaced. Standard product. Suitable for indoor dry service, partition cavities, duct internal lining, anywhere the board stays dry and acoustic absorption is needed. - Foil-scrim-kraft (FSK). Aluminium foil bonded to kraft with a fibreglass scrim. Acts as a vapour barrier and a reflective radiant barrier. Standard for duct external insulation on rectangular ductwork, especially on chilled-water and cold supply-air systems where condensation is the failure mode to design against. - Aluminium foil (ALU). Heavier vapour barrier than FSK, less mechanically durable at joints. Used where reflective performance matters more than handling. - Black glass tissue. Open facing that preserves acoustic absorption. Standard on duct liner boards and acoustic ceilings. - White glass tissue / PVC. Decorative and cleanable facing for plant-room ceilings and food-processing areas. - Bitumen / roofing felt. Used on metal deck roofs in built-up roofing systems where the board sits under a waterproof membrane. A spec error we see often: specifying FSK on an acoustic ceiling where black tissue was the correct choice. The foil reflects sound back into the room instead of absorbing it, and the specifier re-issues the panel order the next month. Pick the facing by the function it must perform — vapour barrier, acoustic, decorative, weather — not by colour. Standard Sizing, Tolerances and What Is Actually Stocked Standard board sizes in metric projects are 1,200 × 600 mm and 1,200 × 2,400 mm; imperial projects use 24 × 48 in (610 × 1,219 mm). Thickness runs 20–150 mm in standard grades, 25–100 mm in the most commonly stocked window, and 100–150 mm in higher-density acoustic grades. Dimensional tolerance is typically ± 2 % on length and width and ± 2 mm on thickness; tighter tolerances cost more and are not usually justified for general building insulation. Boards are supplied in shrink-wrap pallets, typically 4–12 boards per pack depending on thickness. Custom sizes can be cut to order but carry a cutting surcharge and a longer lead time. A practical note on procurement: thickness is not the same as thermal performance. A 50 mm board at 32 kg/m³ and a 50 mm board at 64 kg/m³ have different lambda values and therefore different R-values per unit thickness. Read the thermal resistance from the data sheet for the specific product, not from a generic thickness table. For U-value targets on building elements, run the calculation against lambda at mean service temperature — usually 10 °C for walls, 25 °C for roofs, 40 °C for cold-store envelopes. Procurement Checklist — Six Items to Verify Before Placing an Order The questions below separate a data sheet worth reading from a brochure worth discarding. They are the same six items a quality engineer should be able to answer on every glass wool board quotation. - Density and lambda at the actual operating temperature, not at 25 °C if the application runs warmer or colder. - Compressive strength at 10 % deformation, with the test method referenced on the data sheet, not just a generic "high compressive strength" claim. - Maximum continuous service temperature and peak temperature, written separately on the data sheet. - Facing type and pressure-sensitive adhesive behaviour if the board is to be bonded rather than mechanically fixed. - Water repellency percentage for any external or condensation-exposed application, with the test method cited. - Documentation package: country-of-origin certificate, ISO 9001 quality-management certificate, and compliance with REACH in EU jurisdictions or equivalent national regulations elsewhere. Items 1 to 4 govern whether the panel does its job; items 5 and 6 govern whether the panel survives service and gets through customs. A quotation that does not answer all six in writing is a quotation that will be re-opened during installation. Conclusion — Reading the Spec Sheet Like a Specification, Not a Brochure Glass wool rigid board specification comes down to four reading skills: recognise the density band as a sorting parameter rather than a single answer, read lambda at the actual operating temperature, match compressive strength to the fixing method rather than the nominal density, and choose the facing by the function it must perform — vapour barrier, acoustic, decorative, weather — not by colour. When the application climbs past 250 °C continuous, high-temperature glass wool grades take over until rock wool or PCW modules become the right answer. When the application is acoustic, glass wool dominates rock wool at the same thickness. When the application is structural load-bearing at high temperature, rock wool dominates glass wool. The companion to this guide is our glass wool board applications guide, which steps through the application side of the same material family across building envelope, HVAC and industrial equipment. Read the two together for a complete specification and procurement picture. FAQ: Q: What is the standard density range for glass wool rigid insulation board? A: Standard glass wool rigid boards run from 24 kg/m³ at the lightweight end to roughly 120 kg/m³ at the heavy acoustic and high-temperature end. The most commonly stocked grades are 32, 48, 64 and 80 kg/m³. Density is a sorting parameter rather than an answer to a single spec question; the actual spec that decides suitability is lambda at operating temperature or compressive strength at 10 % deformation. Q: Is glass wool board the same as glass wool blanket? A: No. Both are made from melt-spun glass fibre, but glass wool blanket is a flexible product that drapes over irregular geometry, while glass wool rigid board is bonded into a flat self-supporting panel that holds its shape inside framed cavities. The two products are not interchangeable: blanket wins on speed and conformance, board wins on dimensional stability, bonded facings, and handling under mechanical load. Q: What density of glass wool board should I use? A: Pick density by the application, not by maximum insulation value. 24–32 kg/m³ for friction-fit cavities and partition infill; 32–48 kg/m³ for general wall insulation and steel-structure envelopes; 48–64 kg/m³ for curtain-wall spandrels and metal deck roofs; 64–96 kg/m³ for high-temperature equipment; 80–110 kg/m³ for acoustic ceilings; and ≥ 100 kg/m³ only where load-bearing acoustic or hot-face service is required. Q: What is the temperature limit of glass wool board? A: Standard glass wool board runs 250 °C continuous service with peak excursions 100–200 °C higher. High-temperature grades reach 538 °C continuous. Above 538 °C, glass wool is no longer suitable; high-temperature modules, rock wool board, or PCW modules cover that band. Always read maximum continuous service temperature and peak temperature as separate figures on the data sheet. Q: Is glass wool board fireproof? A: Unfaced glass wool board is classified A1 non-combustible. Faced products can drop classification depending on the facing; a foil or FSK facing is typically A2-s1, d0 in European classifications. For a full breakdown of what A1 means in practice and how facing affects classification, see our dedicated guide on whether glass wool is fireproof. Q: How does glass wool board compare to rock wool board for the same thickness? A: Glass wool board is generally lighter, lower-cost, and has lower lambda at 25 °C, with stronger acoustic absorption at the same thickness. Rock wool board runs higher in compressive strength, supports higher continuous service temperatures (typically 600–1,100 °C), and is the right choice where the application runs above roughly 538 °C. In the 250–538 °C band, both materials are options and the choice is driven by cost, weight and acoustic requirements rather than temperature alone. Q: Which facing should I use on glass wool board? A: Match the facing to the function it has to perform. FSK or aluminium foil for vapour barrier and radiant reflection on rectangular ductwork and external walls. Black glass tissue for acoustic ceilings and duct liner. White tissue or PVC for cleanable decorative surfaces in plant rooms. Unfaced for dry indoor partitions and duct internal lining where acoustic absorption is required. Bitumen or roofing felt for built-up roof assemblies under a waterproof membrane. Q: Is glass wool insulation board waterproof? A: Hydrophobic-treated glass wool board achieves ≥ 98 % water repellency and resists short-term wetting without losing insulation value, but it is not fully waterproof in the sense of being submersible. Long-term water ingress degrades performance and can compromise binders. For any external or condensation-exposed application, specify ≥ 98 % water repellency on the data sheet and pair the board with a continuous facing or vapour barrier. Q: What is the standard size of glass wool board? A: Standard sizes are 1,200 × 600 mm and 1,200 × 2,400 mm in metric projects and 24 × 48 in (610 × 1,219 mm) in imperial projects. Standard thickness runs 20–150 mm, with 25–100 mm as the most commonly stocked window. Dimensional tolerances are typically ± 2 % on length and width and ± 2 mm on thickness. Custom sizes can be cut to order but carry surcharges and longer lead times. Q: What documents should I request with a glass wool board quotation? A: Ask for the country-of-origin certificate, ISO 9001 quality-management certificate, compliance with REACH in EU jurisdictions or equivalent national regulations elsewhere, and a data sheet covering density, lambda at operating temperature, compressive strength at 10 % deformation, maximum continuous and peak temperature, facing type and water repellency percentage with test methods cited. A quotation that does not provide these in writing will be re-opened during installation. ## Pages ### Contact Us URL: https://www.rosetexwool.net/contact/ Heading: Let's talk about your insulation project. Subheading: Whether you need a material recommendation, a custom quotation, or a factory visit — our engineering team is ready to help. Fill in the form below or reach us directly via email, phone, or WhatsApp. FAQ: Q: How do I request a quotation for insulation materials? A: Fill in the contact form on this page with your material type, dimensions, quantity, and operating temperature. Alternatively, email us directly with specifications or drawings. Our engineering team responds within 24 hours with a detailed technical and commercial proposal including freight options (FOB/CIF). Q: What information do you need to recommend the right insulation product? A: To provide an accurate recommendation, we need: (1) maximum operating temperature (°C), (2) application type (furnace lining, pipe insulation, expansion joint, etc.), (3) required dimensions or drawings, (4) any special environmental conditions (chemical exposure, thermal cycling, vibration), and (5) approximate quantity. The more detail you provide, the more precise our recommendation. Q: What are your payment and shipping terms? A: We accept T/T (30% deposit, 70% before shipment) and L/C at sight. Standard shipping is FOB Shanghai/Qingdao port by sea (20-40 days depending on destination). Air freight and CIF door-to-door arrangements are available. All shipments include material test certificates, packing lists, bill of lading, and certificate of origin. Q: Is there a minimum order quantity? A: We accommodate orders of all sizes. For standard catalog products (blankets, boards, pipe sections), there is no strict minimum — a 20-foot container is typical for sea freight. For custom formulations, vacuum-formed shapes, or non-standard dimensions, a minimum order may apply based on production setup requirements. Contact us with your needs for a specific quotation. Q: Can I visit your factory in China? A: Absolutely. We welcome customer visits to our 25,000㎡ manufacturing facility in Zhengzhou. A factory tour includes production line inspection, quality control lab visit, warehouse review, and technical discussion with our engineering team. Please schedule at least one week in advance. We can also assist with visa invitation letters and local accommodation recommendations. ### About Us URL: https://www.rosetexwool.net/about/ Heading: About Us Subheading: Industrial thermal insulation & refractory manufacturer since 1982. FAQ: Q: Is Rosetexwool a direct manufacturer or a trading company? A: Rosetexwool is a direct manufacturer. We own and operate a 25,000-square-meter production facility in Zhengzhou, China, with automated production lines for ceramic fiber, rock wool, and calcium silicate insulation. There are no intermediaries — you work directly with our engineering and export teams for pricing, technical support, and logistics. Q: What quality certifications and testing standards do you follow? A: We are ISO 9001:2015 certified. All products are 100% asbestos-free and tested to international standards including ASTM C447 (thermal conductivity), ASTM C356 (linear shrinkage), ASTM E136 (non-combustibility), API 560, NFPA 285, and EN 13501-1. Every shipment includes a material test certificate with batch traceability data. Q: Can you provide samples before I place an order? A: Yes. We provide free product samples (typically 200×200 mm or A4 sized) shipped via DHL or FedEx. The sample cost is free; you only cover the shipping fee. Larger evaluation samples for plant trials can also be arranged — contact our team with your specifications. Q: What is your production lead time and delivery schedule? A: Standard catalog products (blankets, boards, pipe sections) ship within 15-25 days from order confirmation. Custom specifications, vacuum-formed shapes, and large-volume orders may require 25-40 days. We ship FOB Shanghai/Qingdao or CIF to your destination port. Air freight is available for urgent requirements. Q: Where is your factory located and can I visit? A: Our 25,000㎡ manufacturing plant is located in Zhengzhou, Henan Province, China — the historic center of China's refractory and insulation materials industry. We welcome customer visits and factory audits. Please contact us at least one week in advance to arrange a visit with our engineering and quality teams. ### Aerogel & Microporous Insulation URL: https://www.rosetexwool.net/aerogel-insulation/ Heading: Aerogel & Microporous Insulation — Blanket & Nano Board Subheading: Nano aerogel blankets and microporous boards that hit your thermal target in a fraction of the thickness. Factory-direct, ISO 9001 since 1982. FAQ: Q: What is the maximum service temperature of aerogel insulation? A: Microporous nano boards in this range are rated for high-temperature duties up to 1000 °C, while standard flexible aerogel blankets are rated for continuous service up to 650 °C. Tell us your operating temperature and we will recommend the right form. Q: How thick should aerogel insulation be? A: It depends on your target heat loss or surface temperature and your operating temperature — not on a rule of thumb. As a guide, where mineral wool or calcium silicate would need roughly 50–75 mm, an aerogel blanket typically reaches the same duty at about 10–15 mm. We size the build-up from your actual conditions. Q: Is aerogel worth the extra cost? A: Per square metre, aerogel costs more. It pays back through lower heat loss, faster installation, less metal cladding and reduced risk of corrosion under insulation. It is most clearly worth it where space is tight, access is expensive, or the line runs continuously at high temperature. Q: Is aerogel insulation waterproof? A: Aerogel is intrinsically hydrophobic — the water repellency comes from its nano-porous structure rather than a surface coating, so it is not lost through handling or wear. It still needs correctly sealed cladding; hydrophobic insulation is not a substitute for a weatherproof outer jacket. Q: Can aerogel be used for cryogenic and sub-ambient duties? A: Yes. Aerogel retains very low thermal conductivity at sub-ambient temperatures and is widely used on cryogenic and refrigerated lines, where its thin profile and moisture resistance are both advantages. Q: What forms do you supply? A: We supply flexible nano aerogel insulation blanket and rigid microporous nano insulation board. Both are available factory-direct with thickness and density options to suit the duty. ### Glass Wool Insulation URL: https://www.rosetexwool.net/glass-wool-insulation/ Heading: Glass Wool Insulation — Blanket, Board & Acoustic Subheading: Factory-direct glass wool insulation rated -120 °C to 400 °C. A1 non-combustible, waterproof facings, formaldehyde-free option and NRC up to 0.95. ISO 9001 manufacturer since 1982. FAQ: Q: Is glass wool fire safe? Does it catch fire? A: No, glass wool does not catch fire. It is an inorganic, non-combustible material classified Euroclass A1 under EN 13501-1 and Class A under ASTM E84. It does not ignite, adds no fuel to a fire and releases no significant smoke. It does begin to soften around 500–600 °C, so it is not a high-temperature insulation — its continuous service limit is 400 °C. Q: What is the temperature range of glass wool insulation? A: Glass wool is rated for continuous service from -120 °C to 400 °C. It is a low-to-medium temperature insulation — above 400 °C you should use rock wool (up to 650 °C), calcium silicate (up to 1100 °C) or ceramic fiber (up to 1430 °C) instead. Q: Is glass wool waterproof? A: Standard unfaced glass wool is not waterproof — water can enter the air-filled pore structure and destroy most of its thermal value. Waterproof performance comes from the build-up: hydrophobic treatment during manufacture (98%+ water repellency), a facing such as aluminium foil or a waterproof membrane, and correctly sealed joints. Tell us the environment and we will specify the right combination. Q: What types of glass wool are available? A: The main forms are glass wool blanket (flexible rolls, 10–48 kg/m³, for roofs, walls and large areas), glass wool board (rigid panels, 24–100 kg/m³, for ducts, walls and fire-rated assemblies), and pre-formed pipe sections for pipework. Each can be supplied unfaced or with an aluminium foil, kraft paper, glass tissue or waterproof membrane facing. Q: What is centrifugal glass wool? A: Centrifugal glass wool refers to the manufacturing process, not a different material. Molten glass is thrown out of a high-speed centrifuge and stretched into fibres 5–8 µm in diameter by high-velocity hot air. That finer fibre gives better resilience, lower thermal conductivity at a given density and softer handling than older coarse-fibre products. Q: Is glass wool formaldehyde free? A: Modern glass wool can be made with a formaldehyde-free binder, with no added formaldehyde, dyes or colours. We supply formaldehyde free glass wool for projects where indoor air quality matters — schools, hospitals, offices, residential work and green building ratings. Please specify it at enquiry stage, as it affects the binder we run. Q: What is the difference between glass wool and rock wool? A: Both are Class A1 non-combustible mineral wools. Glass wool is lighter, slightly lower in thermal conductivity (0.032–0.040 vs 0.038–0.050 W/(m·K)) and cheaper per square metre, but is limited to 400 °C and needs a facing for water resistance. Rock wool runs to 650 °C, is inherently hydrophobic, and carries far higher compressive strength — but is heavier and more expensive. Above 650 °C, use calcium silicate or ceramic fiber. Q: Is glass wool good for sound insulation? A: Yes. Acoustic glass wool has a noise reduction coefficient of 0.70–0.95 depending on density and thickness, making it one of the most cost-effective sound absorbers available. It is particularly effective at mid-to-high frequencies, and is used in walls, ceilings, studios, cinemas, offices and machinery enclosures. Adding an air gap behind the insulation improves low-frequency absorption. Q: Can glass wool be used for high temperature insulation? A: No. Glass wool caps at 400 °C, so it is not a high-temperature material. For high-temperature insulation, choose rock wool (up to 650 °C), calcium silicate (up to 1100 °C) or ceramic fiber (up to 1430 °C). Q: What does glass wool insulation cost? A: The cost of glass wool depends on density, thickness and facing. Blanket is the cheapest form and board costs more; foil and waterproof facings add to the price. As a factory-direct manufacturer we typically save customers up to 30% vs trading companies — send your specifications for a 24-hour quote. Q: What density and thickness of glass wool do I need? A: It depends on the application. As a guide: 16–24 kg/m³ for steel-structure roofs and lofts, 32–64 kg/m³ for acoustic panels and wall insulation, 48–64 kg/m³ for external walls, and 64–110 kg/m³ for pipe insulation and ductwork. Thickness typically runs 25–200 mm. Send us your thermal target and we will size it properly. Q: What is glass wool used for? A: Glass wool is used for thermal insulation and acoustic insulation in building walls, roofs and floors, HVAC ducts and smoke exhaust systems, acoustic enclosures and studios, and industrial equipment up to 400 °C. It comes as blanket, mat, board, panel and pipe section. ### Calcium Silicate Insulation URL: https://www.rosetexwool.net/calcium-silicate-insulation/ Heading: Calcium Silicate Insulation — Board, Pipe & Panels Subheading: Factory-direct calsil board, pipe sections and panels to 1100 °C. Density 170–1000 kg/m³, from 0.050 W/(m·K), load-bearing and asbestos-free. ISO 9001 since 1982. FAQ: Q: What thickness of calcium silicate board do I need? A: It depends on your operating temperature, your target heat loss or surface temperature, and the space available. As a guide: 40–60 mm for steam and condensate pipework below 300 °C, 60–80 mm for process pipework at 400–650 °C, and 50–100 mm for boiler and furnace back-up linings. Standard thickness range is 25–100 mm. Above about 75 mm, two thinner layers with staggered joints perform better than one thick layer. Send us your conditions and we will size it properly. Q: What is the density of calcium silicate insulation? A: Calcium silicate is graded by density from about 170 kg/m³ to 1000 kg/m³. Low density (170–220 kg/m³) insulates best and is used for back-up insulation and HVAC. Medium density (220–280 kg/m³) suits steam pipework and boilers. High density (280–500 kg/m³) is used in refineries, cement plants and power generation. Extra-high density (500–1000 kg/m³) is specified for load-bearing pipe supports, fire barriers and contact with molten non-ferrous metals. Higher density means greater strength but slightly higher thermal conductivity. Q: What is the thermal conductivity of calcium silicate? A: Thermal conductivity rises with mean temperature, so any figure must be quoted at a temperature. Typical values are 0.050–0.059 W/(m·K) at 38 °C mean, 0.056–0.079 W/(m·K) at 200 °C mean, and 0.092–0.102 W/(m·K) at 371 °C mean. Lighter grades sit at the bottom of each range and dense structural grades at the top. We supply tested values to ASTM C533 with every quotation. Q: What sizes and thickness is calcium silicate board available in? A: Standard board sizes are 600 × 300 mm and 1000 × 500 mm, with thickness from 25 to 100 mm. Pipe sections are typically 600 mm long, with bores from about 25 mm upward and wall thickness from 25 to 100 mm. Larger formats, non-standard thicknesses and CNC-machined shapes are all available to order — send us the drawing. Q: What is the maximum temperature of calcium silicate insulation? A: Standard grades are rated for continuous service to 650 °C. High-temperature grades, made by a hydrothermal process with quartz sand and lime, run to 1000–1100 °C. Tell us your operating temperature and we will specify the right grade — continuous service above about 1000 °C needs ceramic fiber instead. Q: What is the difference between calcium silicate board and pipe sections? A: Board is a flat rigid panel used for vessel, duct and furnace insulation, fire barriers and fabricated shapes. Pipe sections are pre-formed half-shells manufactured to match a specific pipe outside diameter, with a uniform wall thickness all the way round. On long straight pipe runs, sections install faster and hold thickness more reliably than fabricated board. On large diameters, valves and irregular equipment, board or machined block is usually the practical answer. Q: Is calcium silicate insulation waterproof? A: Not inherently. Calcium silicate will absorb water if it is exposed, and wet insulation loses most of its thermal value and can contribute to corrosion under insulation. Water resistance comes from hydrophobic-treated grades plus a correctly sealed weather-tight cladding. Calsil should always be stored and installed dry, and if it does get wet it needs a slow, controlled dry-out rather than immediate service. Q: Is calcium silicate insulation asbestos free? A: Yes. Modern calcium silicate insulation is completely asbestos-free and is inorganic and non-combustible to Class A1. It does generate fine dust when cut or machined, so cutting should be done in a ventilated area with appropriate respiratory protection, in line with standard workplace dust limits. Q: What is molded calcium silicate? A: Molded calcium silicate refers to the manufacturing process: a slurry of lime, silica and reinforcing fibre is poured or pressed into moulds, then cured in an autoclave under steam pressure. The hydrothermal reaction forms crystalline calcium silicate hydrate, which is what gives the material its strength. Because that strength is crystalline rather than binder-based, calsil does not soften or lose strength as it ages at temperature. Q: What is calcium silicate insulation used for? A: Calsil is used for high-temperature pipe insulation, boiler and furnace back-up insulation, and high-load points such as pipe supports. It is rigid and load-bearing, rated to 650 °C on standard grades and 1000–1100 °C on high-temperature grades, so it is specified where compressible insulation would crush. Dense grades are also used for fire-rated walls and barriers and for contact with molten non-ferrous metals. Q: What is the difference between calcium silicate board and ceramic fiber? A: Calcium silicate board is rigid and load-bearing with high compressive strength, so it suits pipe supports and structural back-up insulation. Ceramic fiber is flexible with very low heat storage, better for lining large furnaces, hot-face applications and rapid heat-up cycles. Many plants use both: calsil for load points, ceramic fiber for linings. Above about 1000 °C continuous, ceramic fiber is the correct choice. Q: What does calsil mean? A: Calsil is the industry abbreviation for calcium silicate insulation. It refers to the same rigid, high-temperature board, pipe sections and blocks made from lime and silica. You will see it written as calsil board, calsil pipe insulation and calsil block — all describe calcium silicate products. ### Ceramic Fiber Insulation URL: https://www.rosetexwool.net/ceramic-fiber-insulation/ Heading: Ceramic Fiber Insulation — Blanket, Board, Paper & Rope Subheading: Factory-direct ceramic fiber to 1430 °C. Blanket, board, paper, rope, cloth, tape and bulk. Low heat storage, ISO 9001 since 1982. FAQ: Q: What is the maximum temperature of ceramic fiber insulation? A: Standard ceramic fiber is classified to 1260 °C, high-purity grades to 1350 °C and zirconia grades to 1430 °C. Continuous operating temperature is lower than the classification figure — typically about 1100 °C, 1200 °C and 1300 °C respectively. We recommend specifying one grade above your actual continuous operating temperature. Q: What types of ceramic fiber are available? A: The main forms are ceramic fiber blanket (flexible needled rolls, 64–160 kg/m³), ceramic fiber board (rigid vacuum-formed panels, 250–400 kg/m³), ceramic fiber paper (thin uniform sheets, 0.5–6 mm), ceramic fiber rope (twisted or braided seals), ceramic fiber cloth and tape (woven textiles), and ceramic fiber bulk (loose fibre for gunning, packing and vacuum forming). Pre-formed modules and vacuum-formed shapes are also available. Q: What is a ceramic fiber rope gasket used for? A: A ceramic fiber rope gasket seals furnace doors, hatch covers, manways, flue joints and inspection ports. It is supplied as round rope for seating in a groove, or square braid where a wider sealing face is needed, and can be reinforced with glass filament or stainless steel wire for strength. It compresses into the seating and stays resilient through repeated heating and cooling cycles. Q: Can ceramic fiber be used for furnace lining? A: Yes — it is the standard lining material for furnaces and kilns. Use ceramic fiber board or modules on the hot face where gas velocity is high, and ceramic fiber blanket for back-up insulation behind firebrick or castable. Ceramic fiber stores roughly a tenth of the heat of a firebrick lining, which gives faster heat-up, shorter cycles and lower fuel use on intermittently-run plant. Q: What is the difference between ceramic fiber and rock wool? A: Temperature is the dividing line. Ceramic fiber runs to 1260–1430 °C with excellent thermal shock resistance and very low heat storage; rock wool is limited to about 650 °C. Choose ceramic fiber above roughly 700 °C, on cycling plant, or where the insulation is in direct contact with flame or high-velocity gas. Below 650 °C — building envelopes, HVAC and general pipework — rock wool is the better value and we will recommend it. Q: Is ceramic fiber safe to handle? A: Installed ceramic fiber is not a hazard, but cutting, machining and removal generate respirable airborne fibre. Refractory ceramic fibers are classified by IARC as Group 2B, possibly carcinogenic to humans. Standard controls apply: cut in a ventilated area, damp down rather than dry sweep, wear respiratory protection, gloves and eye protection, and bag waste. We can also supply bio-soluble low bio-persistence grades where the specification allows. Q: What thickness and density of ceramic fiber blanket do I need? A: Blanket is supplied from 6 to 50 mm thick at 64, 96, 128 or 160 kg/m³. As a guide, 25 mm suits back-up insulation and kiln car seals, 25–50 mm suits furnace wall linings, and two thinner layers with staggered joints outperform one thick layer. Higher density improves resistance to gas velocity and mechanical contact. Send us the hot-face temperature and gas velocity and we will size it properly. Q: What is the thermal conductivity of ceramic fiber? A: It depends on mean temperature and density. Typical blanket values are 0.06–0.08 W/(m·K) at 200 °C mean, 0.10–0.12 at 400 °C, 0.15–0.20 at 600 °C and 0.20–0.30 at 800 °C. Board at 250–400 kg/m³ runs slightly higher but stays more stable. Always compare data sheets at the same mean temperature and density. Q: What is vacuum formed ceramic fiber? A: Vacuum formed ceramic fiber is made by dispersing bulk fibre in water with a binder, lowering a perforated mould into the slurry, and drawing water through it under vacuum so an even layer of fibre deposits on the mould. It produces boards, tubes, cones, rings and custom shapes with uniform density and a good surface finish. Price depends on grade, density and whether a custom mould is needed — send the drawing for a quote. Q: What is the difference between ceramic fiber blanket and board? A: Blanket is flexible, needled and low density (64–160 kg/m³), used for wrapping, general linings and back-up insulation. Board is rigid, vacuum-formed and much denser (250–400 kg/m³) with a hard coatable surface and 1–4 MPa compressive strength, used for hot-face linings at high gas velocity, furnace doors, burner blocks and baffles. Board also machines cleanly; blanket does not. Q: Is ceramic fiber paper the same as ceramic fiber blanket? A: No. Ceramic fiber paper is made by a wet process that produces thin, uniform sheets, typically 0.5 to 6 mm thick, with tightly controlled thickness and density. It is used for gaskets, parting planes, expansion joints and thin compressible layers. Blanket is a needled, flexible, much thicker product used for linings and wrapping. Paper is also available in a bio-soluble grade. Q: Do you supply ceramic fiber pipe insulation? A: Yes. Ceramic fiber pipe and duct insulation is supplied as blanket wraps, pre-formed sections and vacuum-formed shapes for high-temperature process piping, turbine and exhaust systems, and expansion joints. Tell us the pipe outside diameter, operating temperature and available radial space and we will recommend the form and thickness. ### Rockwool Insulation — Blanket, Board, Slab & Pipe Sections | Rosetexwool URL: https://www.rosetexwool.net/rockwool-insulation/ Heading: Rockwool Insulation — Blanket, Board, Slab & Pipe Sections Subheading: A1 non-combustible stone wool for thermal, acoustic and fire protection to 650 °C. Blanket, board, slab and moulded pipe sections in densities 40–200 kg/m³ — factory-direct, ISO 9001 certified, exported to 50+ countries. FAQ: Q: What is the difference between rockwool and rock wool? A: They refer to the same material — stone wool insulation made from molten basalt rock. "Rockwool" (one word) is the common brand-derived term, while "rock wool" (two words) is the generic industry name. Both describe mineral wool insulation produced by spinning molten rock into fine fibers. Q: What density of rockwool slab should I choose? A: It depends on your application: 40–60 kg/m³: Lightweight thermal insulation for cavity walls and timber frames 80–100 kg/m³: General-purpose building insulation, partition walls, sandwich panel cores 120–150 kg/m³: High-compressive-strength applications, flat roof insulation, load-bearing floors 160–200 kg/m³: Industrial high-temperature insulation, furnace linings, marine applications Contact our engineers with your project specifications for a precise recommendation. Q: What certifications do your rockwool slabs have? A: Our rockwool insulation products are tested to: EN 13501-1 Euroclass A1 — Non-combustible (highest fire classification) ASTM E136 — Non-combustibility for North American markets ISO 9001 — Quality management system CE Marking — European conformity ASTM C612 — Mineral fiber block and board thermal insulation Additional certifications available upon request (FM, UL, DNV, etc.) Q: Can rockwool slabs be cut to custom sizes? A: Yes. Standard slab dimensions are 600×1200mm (or 600×1000mm), but we offer custom cutting services for any non-standard size. Simply provide your cutting specifications — including thickness (25–200mm), length, width, and edge profile requirements — and we'll deliver precision-cut slabs ready for installation. Q: Is rockwool insulation waterproof? A: Rockwool is water-repellent (hydrophobic) but not fully waterproof. Our slabs are treated with a hydrophobic agent that repels surface moisture and prevents water absorption under normal conditions. For applications with prolonged water exposure (e.g., underground, submerged), we recommend additional waterproofing measures or our specialized high-density water-resistant grade. Q: How does rockwool compare to fiberglass insulation? A: Rockwool outperforms fiberglass in several key areas: Fire resistance: Rockwool is A1 non-combustible, with a melting point above 1000 °C and continuous service to 650 °C, while glass wool is limited to about 400 °C Acoustic performance: Rockwool's denser fiber structure provides ~30% better sound absorption Water resistance: Rockwool repels moisture; fiberglass absorbs it, losing R-value Dimensional stability: Rockwool won't sag or shrink over time Cost: Rockwool is ~20–40% more expensive upfront but offers better long-term value Q: What is the minimum order quantity (MOQ)? A: Our standard MOQ is 1,000 m² per specification. For trial orders or sample requests, we offer smaller quantities — typically 50–100 m². Contact our sales team for current MOQ and pricing based on your required density, thickness, and delivery destination. Q: What is the typical delivery time? A: Standard orders ship within 15–25 days after order confirmation. For urgent requirements, we can arrange partial shipments within 7–10 days. Delivery time to your port depends on the destination — typically 15–30 days by sea freight. Door-to-door delivery is also available. Q: What is the maximum temperature rockwool insulation can withstand? A: The continuous service rating of rockwool is **650 °C** — the figure used in ASTM C547, C553 and C612 for mineral fiber pipe, blanket and board. Above that, the fibre mat begins to lose thickness and strength. The **melting point is above 1000 °C**, but melting point is a fire-survival property, not a working limit. For sustained duty above 650 °C, specify ceramic fiber (1100–1430 °C by grade) or calcium silicate insulation. Q: Is mineral wool flammable or combustible? A: **Neither.** Mineral wool — which covers rock wool, stone wool and slag wool — is classified **A1 non-combustible** to EN 13501-1 and passes ASTM E136 without igniting. The raw material is basalt that has already been melted at about 1500 °C, so there is nothing left to oxidise. In a fire it does not ignite, does not spread flame, does not drip flaming particles, and produces no significant smoke. Q: What is the rockwool temperature range? A: Rockwool works from cryogenic-adjacent lows up to **650 °C**. On the cold side there is no lower service limit for the fibre itself — it is used down to roughly **−50 °C** and below in cold-store and chilled-water duty, provided a vapour barrier is detailed correctly. On the hot side, **650 °C** is the ceiling for continuous use; the organic binder begins to volatilise around **200–250 °C**, which is a one-off weight loss with no effect on the fibre structure. Q: Can mineral wool insulation be used around fireplaces or furnaces? A: Yes, with a temperature check. Mineral wool is non-combustible and is routinely used around fireplace housings, flue penetrations and appliance surrounds. The rule is the **sustained** temperature at the insulation face: keep it at or below **650 °C**. Where flue gas or radiant heat pushes the hot face above that — directly behind a firebox or inside a furnace chamber — use ceramic fiber blanket on the hot face and mineral wool as the back-up layer. Q: What standard sizes do rockwool boards come in? A: Stock board size is **1200 × 600 mm**, with **1000 × 600 mm** available on request. Thickness runs from **25 mm to 200 mm**, and the most frequently specified building grade is **100 mm** at **1200 × 600 mm**. Boards can be cut to size for non-standard panels, and edges are available square, tongue-and-groove or shiplap. Q: Do you supply moulded rockwool pipe sections? A: Yes. **Moulded pipe sections** are pre-formed split shells supplied for pipe outer diameters from **15 mm to over 600 mm**, in wall thicknesses of **25–100 mm** and densities of **80–150 kg/m³**. They are available plain or factory-faced with aluminium foil, kraft paper or glass cloth. Moulded sections install faster than wrapped blanket and hold their circular shape under metal cladding. See [rock wool pipe insulation](/products/rock-wool-pipe/). Q: Is rockwool suitable for marine insulation? A: It is one of the standard choices. **Rockwool marine insulation** is A1 non-combustible, low smoke, hydrophobic and resistant to vibration and settlement, which suits engine room bulkheads, accommodation fire divisions, HVAC ducts and pipe runs on ships and offshore modules. Marine decks and bulkheads are typically built with 60–120 kg/m³ boards inside assemblies tested to the IMO FTP Code and to EN or ASTM fire-resistance procedures.