1. What Is GB/T 10699?
GB/T 10699 is the Chinese national standard for calcium silicate thermal insulation products. The current version is GB/T 10699-2015, which superseded GB/T 10699-1998 and took effect in 2016. It is the primary production standard used at Chinese calcium silicate manufacturing facilities and applies to products with hot face temperatures up to 1000°C used in equipment, kilns, pipelines, and their accessories.
Revision History
The standard was first published as GB/T 10699-1989, then revised in 1998 (GB/T 10699-1998) and again in 2015 (GB/T 10699-2015). The 1998 revision incorporated references to international benchmarks including JIS A9510-1995 (Japan), ISO/DIS 8143, BS 3982-82 (UK), and ASTM C533-85 (USA), reflecting a deliberate effort to align Chinese calcium silicate standards with international practice. The 2015 revision further refined density grade definitions, added new test methods, and updated product marking requirements.
Product Scope
GB/T 10699-2015 covers calcium silicate insulation products for hot face temperatures not exceeding 1000°C. Applicable product forms include flat boards (P), curved boards/arc segments (H), and pipe shells/tubular sections (G). The standard specifies requirements for classification, technical specifications, test methods, inspection rules, marking, packaging, transport, and storage.
2. Product Classification Under GB/T 10699
GB/T 10699 classifies calcium silicate products along three dimensions: maximum service temperature, product density, and product shape.
2.1 Classification by Maximum Service Temperature
| Type | Maximum Service Temperature | Associated Density Grades | Typical Application Range |
|---|---|---|---|
| Type I (I 型) | 650°C | 240, 220, 170 | Medium-temperature steam pipes, industrial equipment insulation, building services, HVAC duct insulation |
| Type II (II 型) | 1000°C | 270, 220, 170, 140 (1998 ed.) / 150 (2015 ed.) | High-temperature furnace backup insulation, cement kiln linings, glass furnace insulation, petrochemical heater backup, refractory hot face backup |
2.2 Classification by Density Grade
| Density Grade | Maximum Density (kg/m³) | Applicable Types | Typical Compressive Strength |
|---|---|---|---|
| 270 | ≤270 | Type II (1000°C) | ≥0.50 MPa |
| 240 | ≤240 | Type I (650°C) | ≥0.50 MPa |
| 220 | ≤220 | Type I & Type II | ≥0.40 MPa |
| 170 | ≤170 | Type I & Type II | ≥0.40 MPa |
| 150 (140) | ≤150 (≤140 in 1998 ed.) | Type II (1000°C) | ≥0.32 MPa |
Note: The GB/T 10699-1998 edition also included a 140 density grade for Type II. The 2015 revision adjusted this to 150. Users requiring non-standard density products may negotiate specifications directly with the manufacturer per the standard's provisions.
2.3 Classification by Product Shape
| Shape Code | Chinese Term | Description | Common Dimensions |
|---|---|---|---|
| P | 平板 (Flat Board) | Rectangular flat panels, the most common product form | 600 × 300 mm, 600 × 400 mm, 1000 × 500 mm; thickness 20-100 mm |
| H | 弧形板 (Curved Board) | Arc-shaped segments for curved equipment surfaces and large-diameter vessels | Custom arc radius and chord dimensions to match equipment diameter |
| G | 管壳 (Pipe Shell) | Pre-formed cylindrical sections for pipe insulation, typically half-shell or multi-segment | Standard pipe diameters from 21 mm to 610 mm and larger; length 600-1000 mm |
Product marking example: A Type II 1000°C, density grade 220, flat board measuring 600 × 300 × 60 mm would be marked as: II 220P 600×300×60 GB/T 10699-2015.
3. Physical & Thermal Performance Requirements
GB/T 10699 specifies minimum values for key physical and thermal properties. The following tables summarise the principal requirements.
3.1 Density & Mechanical Properties
| Property | Density Grade 270/240 | Density Grade 220/170 | Density Grade 150/140 | Test Method |
|---|---|---|---|---|
| Density | ≤270 / ≤240 kg/m³ | ≤220 / ≤170 kg/m³ | ≤150 / ≤140 kg/m³ | GB/T 5486 |
| Compressive Strength | ≥0.50 MPa | ≥0.40 MPa | ≥0.32 MPa | GB/T 5486 |
| Flexural Strength | ≥0.30 MPa | ≥0.25 MPa | ≥0.20 MPa | GB/T 5486 |
3.2 Thermal Conductivity Requirements
Thermal conductivity is measured at multiple mean test temperatures to characterise performance across the full operating range:
| Mean Test Temperature | Max. Thermal Conductivity (270/240 grades) | Max. Thermal Conductivity (220/170/150 grades) |
|---|---|---|
| 100°C | ≤0.065 W/(m·K) | ≤0.058 W/(m·K) |
| 200°C | ≤0.075 W/(m·K) | ≤0.069 W/(m·K) |
| 300°C | ≤0.087 W/(m·K) | ≤0.081 W/(m·K) |
| 400°C | ≤0.100 W/(m·K) | ≤0.095 W/(m·K) |
| 500°C | ≤0.115 W/(m·K) | ≤0.112 W/(m·K) |
| 600°C | ≤0.130 W/(m·K) | ≤0.130 W/(m·K) |
Test method: GB/T 10294 (guarded hot plate) or GB/T 10295 (heat flow meter). Thermal conductivity increases approximately linearly with mean temperature, following the general relationship λ ≈ 0.056 + 0.00011t W/(m·K), where t is the mean temperature in °C.
3.3 Thermal Ageing & High-Temperature Performance
One of the most demanding requirements in GB/T 10699 is the uniform-temperature firing test (匀温灼烧性能), which verifies product integrity at the maximum rated service temperature:
| Requirement | Type I (650°C) | Type II (1000°C) |
|---|---|---|
| Test Temperature | 650°C | 1000°C |
| Test Duration | 16 hours | 16 hours |
| Linear Shrinkage (max.) | ≤2% | ≤2% |
| Crack Formation | No through-cracks permitted | No through-cracks permitted |
| Residual Compressive Strength (min.) | 270/240 grade: ≥0.40 MPa; 220/170 grade: ≥0.32 MPa | 270 grade: ≥0.40 MPa; 220/170/150 grade: ≥0.32 MPa |
The 16-hour test duration at maximum rated temperature is notably more demanding than the JIS A9510 (Japan) requirement of only 3 hours, making GB/T 10699 one of the more rigorous calcium silicate standards internationally in terms of thermal stability verification.
4. GB/T 10699 vs International Standards
Calcium silicate insulation products are governed by several national and international standards. The following comparison highlights the key differences between GB/T 10699 and other major calcium silicate standards:
| Parameter | GB/T 10699-2015 (China) | ASTM C533 (USA) | EN 14306 (Europe) | JIS A9510 (Japan) |
|---|---|---|---|---|
| Max. Service Temp. | Type I: 650°C Type II: 1000°C | Type I: 649°C Type II: 927°C | CS1: 230°C CS2: 650°C CS3: 1000°C | 1000-1050°C |
| Density Classification | 5 grades: 150, 170, 220, 240, 270 | No explicit density grades; spec by agreement | Multi-property designation code; density declared by manufacturer | ≤220 kg/m³ (simpler spec) |
| Thermal Conductivity Test Temp. | 100°C (multiple temps up to 600°C) | Mean temp 93°C, 204°C, 316°C, 427°C, 538°C (per ASTM C518) | 50°C, 100°C, 200°C, 300°C, 400°C, 500°C (EN 12667) | 70°C |
| Linear Shrinkage Test | 16 hours at rated temp ≤2% | 24 hours at rated temp ≤2% (ASTM C356) | 200 hours at rated temp ≤2% (EN 14706) | 3 hours at 1000°C ≤2% |
| Compressive Strength | ≥0.32-0.50 MPa (by density grade) | ≥0.69 MPa (100 psi) Type I & II | Declared by manufacturer Typical ≥2.0 MPa at 10% deform. | ≥0.30 MPa |
| Flexural Strength | ≥0.20-0.30 MPa (by density grade) | Not specified | EN 12089 method declared by manufacturer | ≥0.30 MPa |
| Chloride Limits for SS | Not explicitly specified | Yes -- references ASTM C795/C871 | Not explicitly specified | Not specified |
| Regulatory Framework | Voluntary national standard (GB/T) | Voluntary consensus standard | Harmonised under CPR 305/2011 (CE marking mandatory) | Japanese Industrial Standard |
| Product Forms Covered | Flat board (P), curved board (H), pipe shell (G) | Block and pipe thermal insulation | Boards, pipe sections, segments, prefabricated ware | Inorganic porous materials broadly |
Key takeaway: GB/T 10699 occupies a middle ground -- more granular in density classification than ASTM C533 or EN 14306, with a linear shrinkage test duration (16 hours) that is significantly longer than JIS A9510 (3 hours) but shorter than EN 14306 (200 hours). For projects requiring compliance with multiple standards, Chinese-manufactured products meeting GB/T 10699 Type II typically also satisfy the core thermal and mechanical requirements of ASTM C533 Type II and EN 14306 CS3, though supplementary testing may be needed for standard-specific criteria such as ASTM chloride limits.
5. Mingfa Compliance with GB/T 10699
GB/T 10699 is the primary production standard at Mingfa's Laizhou, Shandong manufacturing facility. All HCS series and SCS series calcium silicate products are manufactured to GB/T 10699 requirements, with factory test certificates provided with every order.
| Mingfa Product Series | GB/T 10699 Type | Density Grade(s) | Product Form | Key Specifications |
|---|---|---|---|---|
| HCS-17 | Type II (1000°C) | 170 | Flat Board (P) | Density ≤170 kg/m³. Thermal conductivity ≤0.058 W/(m·K) at 100°C. Compressive strength ≥0.40 MPa. Flexural strength ≥0.25 MPa. |
| HCS-20 | Type II (1000°C) | 220 | Flat Board (P) | Density ≤220 kg/m³. Thermal conductivity ≤0.065 W/(m·K) at 100°C. Compressive strength ≥0.50 MPa. Flexural strength ≥0.30 MPa. |
| HCS-23 | Type II (1000°C) | 240 | Flat Board (P) | Density ≤240 kg/m³. Higher mechanical strength for structural applications. Compressive strength ≥0.50 MPa. |
| HCS-25 | Type II (1000°C) | 270 | Flat Board (P) | Density ≤270 kg/m³. Maximum mechanical strength in the HCS range. For applications requiring higher load-bearing capacity. |
| SCS-25 | Type II (1000°C) | 270 | Pipe Shell (G) / Curved Board (H) | Pre-formed pipe sections and curved segments. Thermal and mechanical performance equivalent to HCS-25 board grade. |
Mingfa's manufacturing facility maintains documented quality control procedures aligned with GB/T 10699 inspection rules, including batch sampling, dimensional verification, density testing, thermal conductivity measurement, and compressive strength testing on every production batch.
6. Frequently Asked Questions
What is the difference between GB/T 10699 Type I and Type II?
Type I is rated for a maximum service temperature of 650°C, with density grades of 240, 220, and 170. Type II is rated for 1000°C, with density grades of 270, 220, 170, and 150. Type II also has more demanding thermal ageing requirements: the uniform-temperature firing test is conducted at 1000°C for 16 hours (versus 650°C for Type I), and the residual compressive strength must be maintained above 0.32-0.40 MPa depending on the density grade. In practice, Type II products are required for furnace, kiln, and high-temperature process equipment applications.
How does GB/T 10699 compare to international standards?
GB/T 10699 aligns closely with ASTM C533 and JIS A9510 in core requirements such as density limits, compressive strength minima, and linear shrinkage thresholds. A key differentiator is the linear shrinkage test duration: GB/T 10699 requires 16 hours at the maximum rated temperature, while JIS A9510 requires only 3 hours -- making the Chinese standard notably more rigorous in this respect. GB/T 10699 also has more granular density classification (5 grades versus ASTM C533's binary type system). For European projects, GB/T 10699 Type II products typically satisfy the thermal and mechanical requirements of EN 14306 CS3, though supplementary CE marking documentation requires Notified Body involvement per CPR 305/2011.
Are Mingfa products manufactured to GB/T 10699?
Yes. All Mingfa HCS series and SCS series calcium silicate products are manufactured to GB/T 10699 requirements at the Laizhou, Shandong facility. This is the primary production standard used at Mingfa. Products cover both Type I (650°C) and Type II (1000°C) classifications across multiple density grades (170, 220, 240, 270). Factory test certificates referencing GB/T 10699 are provided with every order, and third-party test reports from accredited laboratories (SGS, CTI) are available upon request for project submission and import clearance purposes.
About 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.
Industrial Insulation Standards & Certifications -- complete standards overview
EN 14306 -- European Standard for Calcium Silicate Factory-Made Products
About Mingfa Insulation -- 34 Years of Calcium Silicate Manufacturing