What is the maximum thermal conductivity (k-value) for cellular glass as per this code?

The maximum thermal conductivity is 0.055 W/(m·K) when tested at a mean temperature of 24 °C (Table 1).

Is cellular glass insulation combustible?

No, it is classified as non-combustible when tested in accordance with IS 3808 (Clause 5.1, Table 1).

What is the minimum compressive strength specified?

The minimum compressive strength is 690 kPa (or 7 kgf/cm²), as per Table 1.

Does cellular glass absorb water?

It has very low water absorption, with a maximum limit of 0.5 percent by volume (Table 1).

IS 13670

: 1993

Specification for cellular glass preformed thermal insulation

CurrentSpecializedSpecificationBIMMaterials Science · Insulation Materials

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This standard specifies the requirements for preformed cellular glass thermal insulation, supplied in the form of blocks or pipe sections. It outlines material composition, physical properties such as thermal conductivity and compressive strength, dimensional tolerances, and test methods for quality assurance.

Specifies requirements for cellular glass preformed thermal insulating materials.

Quick Reference Values

Maximum Thermal Conductivity at 24°C mean temp0.055 W/(m·K)

Minimum Compressive Strength690 kPa

Maximum Water Vapour Permeability2.9 x 10^-6 mg/(s·m·Pa)

Apparent Density Range120 to 165 kg/m³

Maximum Water Absorption by volume0.5 %

Service Temperature Limits-260 to +430 °C

CombustibilityNon-combustible

Practical Notes

Cellular glass is impermeable to moisture and vapor, making it ideal for cryogenic and cold service applications without a separate vapor barrier.

Due to its high compressive strength, it can be used in load-bearing applications like tank bases and pipe supports.

The material is rigid and somewhat brittle, so careful handling and installation are necessary to prevent damage.