Poor fitting climaflex pipe insulation - normal?

[FiscoKing]

Hi,

Just purchased around 75m of 22mm climafex pipe insulation (9mm thick).

Got it home and started to cut it to length. When I place it over the pipes (have to cut it lengthways first to get it one the pipes ) it seems way too big for the pipe. On an un-cut piece of insulation I'm reading 25 - 26mm internal diameter.

Can this be correct?

surely if the insulation is going to do it's job, then it has to hug the pipe?

If you've got big air gaps all the way along the pipe, then when it gets cold, the air currents in the room will get round the insulation and conduct the heat away from the pipe?

Am I missing something here?

I looked on the NMC website, but there is no document that details how the insulation shoud be installed.

Any help appreciated.

Thanks.

 

[Gasguru]

Is it imported and designed for a European pipesize or air con pipe?

9mm wall thickness is not compliant anyway should be 25mm AFAIK.

 

[JohnD]

the thick stuff is required in unheated areas like lofts or underfloor

It is usually a loose sliding fit. I don't think the gap is big enough for convection currents.

 

[FiscoKing]

The insulaiton is stamped 22mm.

At 26mm, it's a very loose fit. Why not just stamp 26mm. The 22mm insulation that I pulled down from my (25 year old) loft fitted like a glove.

Must be what they call 'Vanity Sizing'.

Will speak with the company that makes it tomorrow.

 

[FiscoKing]

NMC confirmed today that the insualtion I had purchased was out of spec.

It is being replaced.

FYI:

I went to a few different stores to compare insulation. All the 9mm wall stuff was just as bad wherever I went. The fit to the pipe seems to get better as the wall thickness gets larger.