Fitting radiator vales to the radiators, help please

happyhero

Hi I have fitted the odd radiator in the past but I cannot remember this part from before so I can't think what I did about it.

Basically I have bought a small towel radiator for our downstairs toilet and a couple of valves, one of which is a TRV4 thermostatic valve. They both have little stubs, don't know what their proper name is but the bits you screw into the radiator that the valves tighten onto.

My question is with these threaded stubs, I cannot see what stops you from screwing them in until they are inside the radiator, I tried with my hands and they seem to stop where you would expect but I am guessing a spanner would just keep driving them in. There does not appear to be any shoulder inside the rad to stop them and the stubs don't seem to have any part on them that will hit and stop them, although amazingly they do stop hand tightening them. Can anyone explain what happens here?

Also how many turns of PTFE tape do you need here?

Do I tighten them quite hard with a spanner or is it the tape that is supposed to stop any leaks?

I don't want to over tighten them if they are just supposed to be tight due to a few turns and the tape.

Any advice or help appreciated

diywhynot

Don't used PTFE. Use Loctite 55.

Ruski

12 turns of ptfe

HTH

Russ

diywhynot

Ruski wrote: »

12 turns of ptfe

HTH

Russ

Not tried Loctite then? Far superior imho.;)

Ruski

Nope - I can do the same by rolling the tape

diywhynot

You don't do gas then...same roll of Loctite 55 is good for both. Six winds for Loctite.:D

Ruski

And 50 times the price

diywhynot

Ruski wrote: »

And 50 times the price

Pay for quality.....but do the maths correctly.:D

Ruski

As you've so much money... I'll :beer:

Ta!

flashg67

No-one seems to have confirmed one of the OPs questions. I too had this problem - did it hand tight and it leaked, so just tightened it until it stopped turning - it didn't fall in the radiator - I think you'll know when it's tight enough (ie before the radiator starts lifting off its brackets...!).Mine did have a spanner shaped part on it though?

Plumbers_Shop_Lee

To answer the op's original question the radiator tail is slightly tapered from back to front so that as it is screwed in it will naturally come to a stop, as others have suggested tho always use thread seal tape/jointing compound on these threads.