Cellular Glass Block & Pipe

Cellular glass is a rigid, closed-cell glass foam insulation with zero water absorption and zero vapour permeability, supplied as blocks and pipe sections. It is used on moisture-critical hot and cold lines, including cryogenic and underground piping, where wet insulation would lose performance or cause corrosion under insulation.

Cellular glass is used on hot lines up to 430°C and also on cold and cryogenic lines, covering both ends of the range with one material. Above 430°C, a higher-temperature material such as Calcium Silicate Block & Pipe Section or Rockwool Pipe Section is used instead.

No, cellular glass has zero water absorption because its cells are closed and impermeable. Its vapour permeability is also zero, so the material itself acts as a vapour barrier, although joints on chilled lines still need to be fully sealed to stop moisture paths through the system.

Cellular glass blocks are 600 mm x 450 mm, and pipe sections cover NB sizes from 15 mm to 600 mm. Thicknesses are 40, 60, 80, 100 and 120 mm, with density from 100 to 165 kg/m³. Pipe sections are specified by pipe NB size and thickness.

Cellular glass has a very high compressive strength of 400 to 800 kPa. This lets it carry load at pipe supports, under tank bases and in buried piping without crushing. It is rigid rather than flexible, so it does not recover if overloaded and must be protected from impact.

Cellular Glass Block & Pipe is chosen where zero water absorption, non-combustibility and high compressive strength are critical, such as underground or load-bearing cold lines. PUF Pipe Section & Board has lower thermal conductivity and is lighter, and is widely used on general chilled-water piping with a proper vapour barrier.

Cellular glass sections are fitted with tight, staggered joints that are sealed with a suitable joint sealant so no moisture path remains on chilled lines. Sections are secured with bands, then jacketed, for example with Aluminum Cladding Sheet & Coil. Butyl Mastic Sealant Tape can be used to seal jacket overlaps and penetrations.

Cellular glass is supplied to ASTM C552, the standard specification for cellular glass thermal insulation. It is non-combustible, Class A1. If your project requires specific test reports against ASTM C552, mention it in your enquiry and we will confirm what is available for the order.

Cellular glass insulation is exported under HS code 7008 00 10, a glass heading rather than the mineral wool heading used for rock wool. It ships palletized and shrink-wrapped to protect the rigid blocks and sections. Confirm the national tariff line with your customs broker.