ASTM C533 Standard Reference
ASTM C533 is the international standard specification for calcium silicate block and pipe thermal insulation. It defines two temperature types:
- Type I: Rated for maximum use temperature of 649°C (1200°F). Mingfa Grade 650 products meet this classification.
- Type II: Rated for maximum use temperature of 927°C (1700°F). Mingfa Grade 1000 and Grade 1100 products exceed this classification.
ASTM C533 also specifies requirements for density, thermal conductivity, compressive strength, flexural strength, linear shrinkage, and moisture content. All Mingfa products can be tested to ASTM C533 upon project request.
LG-Standard Calcium Silicate Products (HCS Series)
Key Takeaways
- HCS series spans 170-250 kg/m3: Thermal conductivity ranges from 0.058 W/m-K (HCS-17) to 0.065 W/m-K (HCS-25) at 100 deg C — select lower density for maximum insulation, higher density where mechanical load-bearing is required.
- ASTM C533 Type I (649 deg C) and Type II (927 deg C): Mingfa Grade 650 meets Type I, while Grades 1000 and 1100 exceed Type II requirements — specify the correct ASTM type in tender documents.
- Five product series available: HCS (general industrial), SCS (high-temp 1100 deg C), MFDJ (aluminum reduction cells), MFGB (steel ladles), MFBL (glass furnaces) — each formulated for specific industry conditions.
- All Mingfa products are manufactured to GB/T 10699 with third-party testing to ASTM C533, EN 14306, and other international standards available on request — custom dimensions and CNC machining offered.
Author's Note: This article draws on Mingfa's 34+ years of calcium silicate R&D and manufacturing experience in Laizhou, Shandong. Technical claims are validated against our in-house laboratory data and published industry standards. About our engineering team
Standard type rated to 1000°C. Low-density calcium silicate insulation board with excellent insulation performance. Bulk density 170-250 kg/m³. Widely used in cement, electrolytic aluminum, steel, and power plant industries for backup insulation behind refractory linings.
| Property | HCS-17 | HCS-20 | HCS-23 | HCS-25 | Test Standard |
|---|---|---|---|---|---|
| Volume Density (kg/m³) | 170 ±10% | 200 ±10% | 230 ±10% | 250 ±10% | GB/T 10699 |
| Flexural Strength (MPa) | ≥0.25 | ≥0.35 | ≥0.45 | ≥0.50 | GB/T 10699 |
| Compressive Strength (MPa) | ≥2.0 | ≥2.3 | ≥2.5 | ≥3.0 | GB/T 5072 |
| Thermal Conductivity (W/m·K) @100°C | ≤0.058 | ≤0.062 | ≤0.064 | ≤0.065 | GB/T 10294 |
| Thermal Conductivity (W/m·K) @400°C | ≤0.100 | ≤0.102 | ≤0.104 | ≤0.107 | GB/T 10294 |
| Maximum Operating Temperature (°C) | 1000 | 1000 | 1000 | 1000 | , |
| Linear Shrinkage (%) | ≤2.0 (1000°C, 16hr soak) | GB/T 10699 | |||
| Moisture Content (%) | ≤5.0 (as manufactured) | GB/T 10699 | |||
References: [1] ASTM C533-17(2023); [2] EN 14306:2015+A1:2018; [3] Mingfa QC Laboratory test data. Full certification details
Products with a maximum operating temperature of 650°C are also available. Contact our technical team for Grade 650 specifications.
LG-High Temperature Calcium Silicate Products (SCS Series)
High-temperature formulation with enhanced thermal stability for applications reaching 1,050-1,100°C. Suitable for burning zone backup insulation in cement kilns and high-temperature industrial furnace linings.
| Property | SCS-25 | Test Standard |
|---|---|---|
| Volume Density (kg/m³) | 250 ±10% | GB/T 10699 |
| Flexural Strength (MPa) | ≥0.50 | GB/T 10699 |
| Compressive Strength (MPa) | ≥3.0 | GB/T 5072 |
| Maximum Operating Temperature (°C) | 1100 | , |
| Linear Shrinkage (%) | ≤2.0 (1050°C, 3hr soak) | GB/T 10699 |
| Thermal Conductivity (W/m·K) @100°C | ≤0.065 | GB/T 10294 |
| Thermal Conductivity (W/m·K) @400°C | ≤0.108 | GB/T 10294 |
| Moisture Content (%) | ≤5.0 (as manufactured) | GB/T 10699 |
Hard Silica-Calcium Composite Brick -- MFDJ Series (Electrolytic Aluminum)
Substrate synthesized from siliceous and calcareous materials through autoclaved hydrothermal compression. Features uniformly distributed micron and nano-sized pores (porosity 85-91%). Used in electrolytic aluminum reduction cells as backup insulation behind the cathode lining.
| Property | MFDJ-30Q | MFDJ-40 | Test Standard |
|---|---|---|---|
| Temperature Grade (°C) | 1000 | 1000 | , |
| Density (kg/m³) | 300 ±10% | 400 ±10% | GB/T 10699 |
| Compressive Strength (MPa) | ≥2.0 | ≥2.5 | GB/T 5072 |
| Linear Shrinkage 900°C × 3h (%) | ≤1.2 | ≤1.2 | GB/T 10699 |
| Thermal Conductivity @900°C (W/m·K) | ≤0.11 | ≤0.11 | YB/T 4130 |
| Porosity (%) | 85-91 | 85-91 | , |
Hard Silica-Calcium Composite Brick -- MFGB Series (Steel Ladle)
High-density formulation for permanent backing in steel ladles. Designed to withstand the mechanical stresses of ladle tilting, crane lifting, and repeated thermal cycling without cracking or crushing. Used behind working refractory linings (alumina-magnesia carbon brick, magnesia-carbon brick).
| Property | MFGB-40 | MFGB-50 | MFGB-60 | Test Standard |
|---|---|---|---|---|
| Temperature Grade (°C) | 1000 | 1000 | 1000 | , |
| Density (kg/m³) | 400 ±10% | 500 ±10% | 600 ±10% | GB/T 10699 |
| Compressive Strength (MPa) | ≥4.0 | ≥5.0 | ≥6.0 | GB/T 5072 |
| Linear Shrinkage 900°C × 3h (%) | ≤1.2 | ≤1.2 | ≤1.2 | GB/T 10699 |
| Thermal Conductivity @900°C (W/m·K) | ≤0.12 | ≤0.13 | ≤0.14 | YB/T 4130 |
Hard Silica-Calcium Composite Brick -- MFBL Series (Glass Furnace)
Specialized formulation for glass melting furnace insulation. Low iron content to minimize discoloration risk. Excellent dimensional stability under prolonged high-temperature exposure typical of glass furnace campaigns (5-15 years).
| Property | MFBL-35 | MFBL-45 | Test Standard |
|---|---|---|---|
| Temperature Grade (°C) | 1000 | 1000 | , |
| Density (kg/m³) | 350 ±10% | 450 ±10% | GB/T 10699 |
| Compressive Strength (MPa) | ≥3.0 | ≥4.0 | GB/T 5072 |
| Linear Shrinkage 900°C × 3h (%) | ≤1.2 | ≤1.2 | GB/T 10699 |
| Thermal Conductivity @900°C (W/m·K) | ≤0.11 | ≤0.12 | YB/T 4130 |
Need a Printable Data Sheet?
Contact our technical team for PDF data sheets with full thermal conductivity curves and standard compliance certificates for your project documentation.
Request Data SheetCustom Sizes Available
All products can be manufactured in custom dimensions and thicknesses. CNC machining available for complex geometries, tapered shapes, and precision cut-outs.
Inquire About Custom SizesAbout the Author — Mingfa Insulation Technical Team
Mingfa Insulation's technical content is authored by our in-house engineering team with 34+ years of specialized experience in calcium silicate R&D and manufacturing. Established in 1991 as a joint venture with the China Building Materials Academy, our team holds ~20 national patents. For technical inquiries, contact lzmfgr@163.com.