Armaflex Class O Pipe Insulation 20mm x 19mm

If you are lagging pipe that is 20mm on the outside, such as 20mm plastic or multilayer, Armaflex Class O Pipe Insulation 20mm x 19mm is the matching tube. It gives a 19mm wall of closed-cell foam, a step up from the basic 13mm grade, so it handles frost risk and sweating cold lines better.

Armaflex Class O Pipe Insulation 20mm x 19mm on the job

A tube made for the common copper sizes will not sit right on 20mm. One is too tight to slide along and the other leaves a loose gap where warm, damp air creeps in. So match the bore first, then choose the wall. The rubber-based foam bends round gentle curves without creasing, but at a tight elbow it is better cut and glued.

• Bore: for pipe 20mm outside diameter
• Wall: 19mm thick
• Size over the foam once fitted: about 58mm
• Each tube is 2 metres long

Leave space for that 58mm finished size at clips and joist notches, because squashing the foam thins it. If the pipe is going in new, slide the tube on first and make the joints after, keeping it well clear of any soldering heat. The rest of the sizes are listed under pipes, hoses and insulation.

Collecting it in Glasgow

These tubes are collection only. Reserve them online, then call 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: 20mm bore, 19mm wall, 2m lengths
• Standard or approval: Class O fire performance, as named
• Suitable for: Insulating 20mm pipe

Common Questions

What pipe does 20mm bore Armaflex fit?

It is made for pipe of about 20mm outside diameter. Measure the pipe before you buy, because a loose tube leaves an air gap and a tight one splits.

Can I slit 20mm x 19mm Armaflex to fit pipe already in place?

Yes, cut along the length with a sharp knife, wrap it round the pipe and close the seam with Armaflex adhesive. Slide it on unslit where the pipe end is free.

Is 19mm wall enough for an outside run?

It is a good middle grade for cold areas. Outdoors, protect it from sunlight as Armacell advise, because UV breaks down the surface.