Why ptfe tape on compression fitting threads

[wheeto]

I wonder if NASA use PTFE on the o-rings on their shuttle boosters. Maybe they could learn a thing or two from this thread. :lol:

Any idea on the freezing temp of PTFE?

 

[Howsie]

-232 degrees Celsius

 

[ggman]

This debate looks like that we are trying to establish the genderof the Angels: are they male or female?
The compression jointare a strong mechanical union, I personally won't use anything on the olive but I would only using the betterquality joint, expensive but won't gowrong at later date, maybe we have problem when trying to rush the job. Pipes in good condition, nice and clean,copper olives on copper pipes, pipes well aligned fully pushed in and one thingvery important is lubrication of the thread and nut with light oil.
I am a retired electronic engineer, did few years ofplumbing years ago worked a lot on refrigeration
Now you will call me DIYer.
Regards

 

[Mickyplumb]

Been using ptfe on compression olives for 10 years, can't remember ever having a leak ! My train of thought s why take the chance ? Imaging fitting a new heating system, flushing, refilling, adding inhibitor and then finding you've got a weep on on a rad valve ? What a waste of time and inhibitor !!!!

 

[Bernie2]

Hmm!

The original idea of using anything on a compression fitting was because the mating surfaces of both the olive (ring) and the fitting where not always a true smooth machined face and microscopic fault lines that let water pass where said to exist. The UK made fittings claim their machining is so good no jointing paste or tape to fill the imperfections is required. I always use paste however, because its easier to put on than PTFE. Saying that of course you have to go careful how you apply and none goes down the pipe.

 

[adam84]

Ive only used ptfe when the fitting just want stop weeping, as a mechanical fitting it shouldnt need additional ptfe or any other compound if it is installed properly, having said that i got some 22mm compression elbows from a back of beyond of merchants once and none of them would stop leaking without ptfe.

 

[Mickyplumb]

I worked with a lovely old guy about a month ago on an install. He uses boss white and hemp on compression fittings.....I guess old habits die hard !! Still, imagine being the home owner and getting the occasional mouth full of horses tail in your cup of tea!!!! Yuk
Are the new generation of equine critters WRAS approved these days !!!!!!!!???????

 

[WHPES]

Boss White and hemp must not be used for potable systems under water regs as its organic and can support microbial growth. Slic Tite or Hawk Blue are acceptable.

I use Boss White on all non-potable compression fittings and ptfe on potable.

 

[Mickyplumb]

Boss White and hemp must not be used for potable systems under water regs as its organic and can support microbial growth. Slic Tite or Hawk Blue are acceptable.

I use Boss White on all non-potable compression fittings and ptfe on potable.

Yep, i must admit i knew that it can't be used on drinking water, he was using it in an airing cupboard to fit a cylinder, etc.

Having said that, the customer now walks on all fours, has a thick mane of black hair down her neck....only answers to the name of Shergar !

 

[Phil]

Anybody had trouble with Danfoss TRV's lately?

Very shallow fitting depth and a very hard brass olive has resulted in the dreaded wet finger the day after around the pipe.

I always have to PTFE these olives now as three in a row leaking is a right pain.