Concealed valve fittings

[JonesJ89]

Hi guys I'm just fitting a new concealed shower valve in my home.
My question is I bought 2 22x15 adapting couplers and 2 15x15 adapting couplers, even with 15 wraps of PTFE I have a feeling the thread isn't going in far enough, I can literally tighten it all the way by hand ,
Is their any longer thread fittings I should be using ? Or will these be okay .
I have attached a picture of the valve and the fitting I purchased

Thanks

 

[Ben-gee]

Looks like all the ptfe had been pushed out as you wound fitting in.
Scratch across the threads in a few places with a hacksaw blade before you wrap the tape. Make sure you wrap the tape the correct way- hold the compression nut in your left hand with the male iron threads to the right, wrap the tape clockwise pulling it fairly tight each turn.

 

[JonesJ89]

Hi Ben thanks for reply please see attached images this is how I have been wrapping which I believe is how you are telling me to do it ? Literally when I wind it in it goes all the way barring a tiny nip at the end and I'm worried it will leak

 

[Ben-gee]

You got it that’s correct.
If it goes in too easily, just try more turns, some fittings are looser than others and twenty turns could be needed.

Plumb it in, flush through valve on both hot and cold - then leave it for a few days to check for leaks if you’re worried.

Is it pressurised system or pumped gravity? ( if so , negative or positive pump?)

 

[JonesJ89]

Fantastic I'll try it again with 20 turns and see if it seems tighter, could I also put a smear of jointing compound over the PTFE tape or is it not necessary?

And it's a pressurised system combi boiler !

Thanks