PTFE on compression fittings?

[nickso]

the usual snobbery i see.

nothing wrong with PTFE on a buggered olive or even a marginal one. particularly if its a hassle to DD or bung again.

to those saying PTFE isn't needed on new joints, try using the ****e fittings BG are currently using, bet you would PTFE it then.

another minor benefit of PTFE over jointing compounds is PTFE doesn't set solid like some compounds do making it easier to remove in the future. before anyone chimes in with the classic "PTFE looks awful on a joint", if done correctly (one or two wraps on the leading face of the olive) you will never know it's there.

 

[kirkgas]

... perhaps the quality of the stuff we buy now isnt as good and there are more leaks being left ....

I don't believe there was ever a golden age when joints never leaked.

Not since the days of threaded gas-barrel, boss-white and hemp, anyway.

you are probably right, but in general the quality of things we buy now doesnt seem as robust as years ago, or am i just thinking o' the good ol days

 

[Norcon]

If the sealing seat or olive is damaged and pressure forces fluid through then the threads are next..............

 

[Axel]

One of the risks of using PTFE to improve the seal of the olive to the fitting & backnut is that you might end up not tightening it enough to prevent a catastrophic failure - usually, (without PTFE) if a compression fitting is tight enough to not leak under mains pressure, there is no danger of the fitting blowing off the pipe under pressure - there are 2 elements to the olive biting into the pipe - physically holding it strong together, and secondly (and of secondary importance) making a leak proof seal. PTFE might achieve a leak proof seal without the necessary torque applied to the backnut to make the fitting tight enough to prevent the pipe slipping out under pressure.

 

[JohnD]

Have you ever known that happen?

 

[Axel]

Admittedly no, I am trying to find a valid argument against the non-professional practice that we so despise....

In other words, I made that up, but it's probably true.

 

[seco services]

I am trying to find a valid argument against the non-professional practice that we so despise....

you don't need to find an argument. it's a bodge job.

 

[Rhondo]

but it's probably true

Naw... that's wrong. The ptfe reduces friction thus the olive takes a tighter grip from a lower torque. All threads should be ptfe'd.
EDIT
Personally, I'm not interested in getting dragged into a discussion here but it would be a pity to leave some points of misinformation you posted unchallenged.

 

[seco services]

All threads should be ptfe'd.

get the f*c should they.

 

[PRS1]

I think one of the main differances is that if u just ask for a 15mm comp elbow they give u imported ****e that squeels like fluff when tightening were as fittings like conex or kutterlite are a dream.
If i have any doubts i tighten , undo and just a thin smear of jet blue,but 9 times out of ten i dont bother with anything.
Prefer copper olive too on small fittings.

 

[JohnD]

As far as I can see, PTFE prevents leaks and the cost is minimal

the time taken is far less than fixing a leak

Only reason we have seen for being anti is traditionalist old plumbers.

In my house I would rather not have a leak and don't have to worry about an old feller in a cloth cap and blue overalls sneering at my work.

 

[compheat]

just to change the subject slightly

Can any one tell me how many turns a compression nut should go before its tight.

 

[Axel]

PTFE on olives or compression joint threads is a BODGE and a surveyor worth his / her salt might spot it one day and put a negative comment referring to non-professional plumbing on a house buyer's survey.

 

[DIYDANDY]

PTFE on olives or compression joint threads is a BODGE and a surveyor worth his / her salt might spot it one day and put a negative comment referring to non-professional plumbing on a house buyer's survey.

Balls...

 

[JohnD]

a leak on a joint is an actual problem. PTFE on an olive is only an imaginary slight.