Radiator valve keeps on turning

[DJS1]

I'm fitting a chunky tubular radiator that has a 15mm reducer fitted for the valves to screw into. When I screwed the valves in I realised there was nothing for the valves to butt up to and they would keep going in until the valve body started to foul the edge of the radiator.
On other radiators you can tighten the valve until it will obviously not turn any more but that's not the case here.

Has anyone experienced this before, and if so, how far do you screw the valve in and do you just have to use lots of PTFE to stop it leaking?

Thanks for your help.

 

[JohnD]

is it the radiator tails you are screwing in?

this is a separate part, supplied with the rad valves

what make and model of rad valve are you using?

the thread should be tapered, so it gets tighter as it goes in

 

[DJS1]

Yep, it's the tail piece I'm fitting, basic TRV's from Wickes. Possibly I was trying too hard as they do get tighter, but I think I forced it past where it should stop and then it just keeps on going.

The fact there are reducers fitted means there's only about 10mm max of thread that is in contact with the tail so maybe that's why I was able to force it through.

Thanks for your help, I'll stop where it seems natural and hopefully it will be fine.

 

[JohnD]

you can get Gasfitters PTFE tape which is extra thick

might help?