Armaflex Self Seal Class O Insulation 54mm x 9mm

On big commercial pipework, Armaflex Self Seal Class O Insulation puts a 9mm wall of closed cell foam round 54mm copper, with a self-adhesive seam. It suits big pipe inside the warm part of a building, where space is tight.

Where 54mm Armaflex self seal insulation goes

54mm copper is common on commercial heating and hot water mains, and in plant rooms feeding several zones. Its closed cells keep water vapour out of the foam. For valves and flanges on runs this size, sheet insulation cut to shape usually makes a neater box than tube.

• Bore: 54mm, for 54mm copper
• Wall thickness: 9mm
• Overall size: roughly 72mm
• Length: 2 metres, pre-slit

Pick clips and sleeves to suit the lagged size, not the bare pipe. If you need another bore or wall, check our pipe insulation section.

Fit it to a dry pipe, not one that is sweating, and put the seam where you can press it home along its length. Seal the butt joints with Armaflex adhesive or tape.

Glasgow collection for 54mm x 9mm pipe lagging

Visit Plumb Parts, 555 South Street, Glasgow G14 0QX. Counter hours: Mon-Fri 8am-5pm and Sat-Sun 8am-1pm. The 54mm tube can be ordered online as well.

Specification

• Brand: Armaflex
• Range: Class O Self Seal
• Maker code: AF-CO-09X054-A
• Material: Closed cell elastomeric foam
• Connection: Pre-slit tube with self-adhesive seam
• Sizes: 54mm bore, 9mm wall, 2m long
• Standard or approval: Class O, as named
• Suitable for: Heating, hot and cold water pipework
• Pack quantity: One 2m tube

Common Questions

Is Armaflex Self Seal 54mm x 9mm fire rated? Yes, it’s Class O to BS 476 Parts 6 and 7, so it’s fine for jobs where the spec calls for Class O.

Is Armaflex closed cell insulation? Yes, it’s closed cell nitrile rubber foam from Armacell. That gives it a built-in vapour barrier, so it works on cold and chilled pipes as well as hot ones.

How do I fit Armaflex Self Seal insulation on 54mm pipe? Wipe the pipe clean and dry, open the slit tube over it, peel the backing off the tape strips and press the faces together from one end. Butt each 2m length tight to the next and glue the end joints with Armaflex adhesive so there’s no cold gap.

Can Armaflex Self Seal be used outside? It’s really meant for indoor pipework. If a run goes outside, protect the foam from sunlight with a suitable coating or cladding, as UV will break down the surface over time.

How do I cut Armaflex insulation neatly? Use a sharp knife with a long blade and cut in one steady stroke rather than sawing at it. For corners, mitre the ends and glue them so there’s no gap.

How many lengths of 54mm Armaflex do I need? Every piece is 2m long, so divide your run in metres by two and round up. Grab one or two extra to cover offcuts at bends, tees and valves.

What clip size should I allow for once it’s lagged? With the 9mm wall on 54mm pipe, allow roughly 72mm across when you’re choosing clips or drilling holes.