Fitting TRVs on to 10mm copper tube

[Lobster]

I'm fitting some radiators, with 10mm pipe, and was going to use some unused TRVs which I have in, but these are for 15mm pipe. Now, ISTR in the past seeing a TRV (15mm) fitted with a reducer to enable it to be used with 10mm tubing. A Screwfix search has thrown up the following:

(or and I'm wondering, is that what this is? ie, will it work in any TRV? I can't remember whether the one I saw before had a bespoke insert or not.

Thanks David

[Andy Hall]

You can get concentric ring sets that will fit into the valve in place of the olive and do this, but they are a PITA to fit and somewhat dodgy because they tend to leak IME.

A better solution is a 15mm male to 10mm female adaptor.

Have a look at

part number 9214. Type the part number into the product search and then scroll down the resultant page.

I used the 8mm version of these very successfully. Most of the fitting disappears into the valve so it's very neat. It's also a solid solution in terms of not leaking.

[.]

The Screwfix part is the one I used with my 8 mm. It worked fine with several 15 mm trvs. When you tighten the nut the reducer breaks in 2 and one part squeezes the other onto the pipe like an olive. The only problem I had was that the reducer was a little bulky and the nut only just caught the thread so it had to be perfectly square.