Armaflex Class O Pipe Insulation 42mm x 25mm

Armaflex Class O Pipe Insulation 42mm x 25mm gives 42mm copper or 1 1/4 inch steel pipe a thick 25mm wall. Use it where a pipe of that bore carries chilled water, or where a cold main is exposed to frost in an outbuilding or loading bay.

Fitting Armaflex Class O Pipe Insulation 42mm x 25mm

The thick wall is stiff enough that wrapping it round hung pipe takes a little care. Cut cleanly along one side, open it round the pipe and glue both faces of the cut with Armaflex 520 adhesive. Let the glue go tacky first, then press it closed. At bends, mitre the foam rather than bending it hard.

• Suits 42mm copper and 42.4mm steel
• 25mm closed-cell wall
• About 92mm across once on
• Supplied in 2 metre lengths

Expect roughly 92mm over the foam, so it needs generous spacing between pipes and larger openings through walls. For chilled lines, the support points matter too, because a metal clip on bare pipe becomes a cold spot that drips. Other sizes sit under pipes, hoses and insulation.

Where to get it in Glasgow

It is collection only. Buy it on the website and come for it at Plumb Parts, 555 South Street, Glasgow G14 0QX, Mon-Fri 8am-5pm or Sat-Sun 8am-1pm.

Specification

• Brand: Armaflex
• Range: Class O pipe insulation
• Material: Flexible closed cell elastomeric (nitrile rubber) foam
• Sizes: 42mm bore, 25mm wall, 2m lengths
• Standard or approval: Class O fire performance, as named
• Suitable for: Insulating 42mm pipe

Common Questions

When is 42mm x 25mm Armaflex the right choice?

On 42mm chilled water, or cold water pipes in very cold or damp areas. It is the heaviest wall listed for 42mm.

Can the 42mm x 25mm tube be slit and glued?

Yes. Cut a slit along its length, open it round the 42mm pipe and glue the seam with Armaflex adhesive, pressing the faces firmly together.

How do I insulate a 42mm bend?

Cut the tube into mitred segments and glue them together round the bend. That keeps the wall thickness even on the outside of the bend.