Fitting tap isolators with pre-roughened threads

[need_help100]

Hi all,

I bought these tap isolators:

Angle valve 1/2″

www.grohe.co.uk

So how do I fit the pre- roughened ends?

I assume they go into wall plate elbows fitting inside my stud wall.
Do you put PTFE tape on them (and how many windings should you use)?

Cheers

 

[polesapart]

Loctite 55 cord would be better than PTFE tape. Videos online for how much -its more of a "feel" thing, you want to feel some resistance on the last turn(s).

Could use hemp and jointing compound- some people disapprove but the continentals still use, indeed the threads are pre-roughened to help catch the hemp strands.

 

[Madrab]

Do you put PTFE tape on them (and how many windings should you use)?

I would happily use PTFE tape - I use gas tape as it's what I have to hand, wind 6-7 turns on. Watch as it's tightened to make sure it finishes up in the correct orientation.

 

[Wilson78]

No differant imo.
All I've known it being good for is stopping the ptfe tape from slipping while wrapping it around threads.
And 6 turns is nowt.
And these days the fittings take MORE turns than years ago.
A rad valve tail used to take roughly....I dunno....15 or less.. now I'm around 20 plus.
If I don't over do it, the tail will be slack when I tighten it into it's Wotsit

 

[Wilson78]

I would happily use PTFE tape - I use gas tape as it's what I have to hand, wind 6-7 turns on. Watch as it's tightened to make sure it finishes up in the correct orientation.

Hiya fella...
I noticed your very familiar name...
@Madrab ... & had to say 'ELLO'...
...So..."ELLO!"

 

[Madrab]

And 6 turns is nowt.

Gas PTFE tape is much thicker than water tape - I use it all the time - I can guarantee that 6-7 turns will be more than enough, outside taps - shower heads, bayonet gas valves, gas hob connections, cooker hoses etc, all use the same number of turns. That includes rad tails too. Fitted 3 yesterday with exactly that amount of tape. Works every time.

If using Water PTFE tape then yes it needs a lot more turns.

 

[jacoscar]

Hi all, I have bought the same valves and have the same question.
I have read that these ribbed threads don’t need PTFE, but a particular threaded female wall plate with a rubber seal at the end.

 

[Madrab]

I have read that these ribbed threads don’t need PTFE, but a particular threaded female wall plate with a rubber seal at the end.

They can use a rubber sealing washer or use tape/thread but so can male fittings without roughened threads. All the roughened threads do is allow the tape/thread to be gripped when the fitting is tightened. Used to use a file and do the same to allow the threads to grip the tape.

The only type of thread that doesn't require tape/thread/washer is NPT (tapered) as the threads mesh together rather than the parallel threads of the BSP fitting that don't mesh together, hence the need for some type of sealing medium/o-ring/washer.