Rigid High-Temperature Thermal Insulation Board
Calcium Silicate
Calcium silicate is a rigid, load-bearing thermal insulation board suited to high-temperature pipe, vessel, and equipment insulation. We supply calcium silicate board and pipe sections for industrial insulation, fire protection, and high-temperature gasket backing applications in power generation, refining, and heavy industry.
At a Glance
Temperature Range
Up to 927 °C continuous per ASTM C533 Type II; high-temperature grades to 1000 °C per EN 14306
Thickness Range
25 mm to 100 mm
Available Forms
Colours
Technical Properties
Typical values across stocked grades. Specific grade data sheets available on request.
Physical Characteristics
Density
200–350 kg/m³
Chemical Resistance
Resistant To
- Neutral and mildly alkaline environments
- Most process gases at service temperature
- Mineral oils at temperatures below decomposition
Limited Resistance
- Acids (calcium silicate is alkaline, so acidic media neutralise the binder)
- Sustained water immersion (reduces mechanical strength over time)
Not Recommended
- Acidic process environments, where the material degrades. Use ceramic fibre or perlite instead.
- Continuous water contact or immersion. Use closed-cell foams or cellular glass for wet insulation
- Direct contact with austenitic stainless steel without an ASTM C795-compliant grade — uncontrolled chloride leaching causes under-insulation stress corrosion cracking
Environmental Ratings
Flame Rating
Non-combustible per AS 1530.1
Standards & Certifications
Standards Compliance
Common Applications
- High-temperature pipe insulation (power generation, refining)
- Boiler and vessel external insulation
- Fire-rated wall and ceiling insulation
- Kiln car deck insulation
- Backing for furnace door gaskets
- Equipment supports and thermal breaks
- Stack and ductwork insulation
Not Recommended For
- Rigid and brittle, so it cannot conform to irregular surfaces. Use ceramic fibre blanket for complex geometries.
- Not acid-resistant — alkaline composition reacts with acidic media. Check process environment.
- Loses mechanical strength with prolonged water exposure. Store dry and protect installed surfaces from rain
- Specify ASTM C795-compliant grade for direct austenitic stainless steel contact: compliance requires passing both ASTM C871 ion-ratio analysis and ASTM C692 SCC physical test, not simply low chloride content
- Heavier than ceramic fibre blanket, with density 2–5× that of equivalent fibre products. Consider weight loading on supports.
- Cannot be used as a pressure-sealing gasket. It is thermal insulation, not a sealing material
Available Grades
Calcium Silicate Board — ASTM C533 Type II (927 °C)
General-purpose rigid insulation board for pipe and vessel insulation classified to ASTM C533 Type II (927 °C / 1700 °F continuous). Load-bearing and machinable for site-fit installation.
High-Temperature Calcium Silicate (1000 °C, EN 14306)
Premium high-temperature grade (Promasil-class or equivalent) classified to EN 14306 for service to 1000 °C continuous. Suited to refining, petrochemical, and power applications above the ASTM C533 Type II ceiling.
ASTM C795-Compliant Calcium Silicate (Stainless Steel Contact)
Calcium silicate qualified per ASTM C795 — passes both ASTM C871 ion-ratio analysis and ASTM C692 stress corrosion test on 304 stainless coupons. Specified for direct contact with austenitic stainless steel piping and vessels to prevent under-insulation SCC.
Calcium Silicate Pipe Section
Pre-formed half-shells for pipe insulation. Available in standard pipe diameters with scored inner surface for fit adjustment.
Related Materials
Need Calcium Silicate?
We supply calcium silicate in sheet, roll, and custom die-cut forms. Contact our team for pricing, data sheets, or technical assistance.
Disclaimer
This resource is provided for general engineering reference only and does not constitute professional advice, specification, or guarantee of performance. Actual results depend on specific application conditions. Universal Gaskets Pty Ltd accepts no responsibility or liability for decisions made based on this information. For full terms, see our Terms & Conditions.