133mm Pipe Insulation

133mm pipe insulation fits steel pipe with a 133mm outside diameter — equivalent to 5 inch nominal bore steel pipe, used for large commercial and industrial heating mains, chilled water distribution, district heating and process pipework. We stock a full range of 133mm pipe insulation from the UK's leading manufacturers including Armaflex, K-Flex, Rockwool and Kingspan Kooltherm, in wall thicknesses from 25mm to 60mm.

Types of 133mm Pipe Insulation

Armaflex EVO 133mm — Class O closed-cell nitrile rubber foam with built-in vapour barrier. Available in 25mm wall. The professional's choice for chilled water and HVAC at this pipe size
K-Flex ST 133mm — Class O elastomeric foam equivalent to Armaflex. Available in 25mm wall
Rockwool Rocklap 133mm — A1 non-combustible mineral wool with foil facing for high-temperature applications up to 250°C. Available in 25mm, 40mm, 50mm and 60mm wall
Kingspan Kooltherm 133mm — Premium phenolic foam (λ = 0.025 W/mK) for space-constrained plant rooms and risers where thinner walls are required

Which Wall Thickness Do I Need?

25mm wall — Standard for commercial HVAC, chilled water and heating mains. Meets Part L and CIBSE Guide C for most commercial applications at this pipe size
30–40mm wall — Enhanced performance for district heating, exposed pipework and high-performance specifications
50–60mm wall — High-temperature heating mains, steam and industrial process pipework (Rockwool)

133mm Pipe Insulation — Common Applications

Large commercial and industrial heating mains (5 inch steel pipework)
Chilled water mains in large commercial HVAC and data centre installations
District heating and heat network primary mains
Steam distribution and high-temperature process pipework
Industrial cooling and process systems

How to Measure Pipe Insulation

Pipe insulation is sized by the outside diameter (OD) of the pipe. For steel pipe, 133mm refers to 133.0mm OD (5 inch nominal bore). Always measure the outside of the pipe before ordering.