Compression fitting woes/advice + Philmac fitting outcome

[shd1970]

Once again, i'm left frustrated by a compression fitting that is slightly weeping but this time, its on my new stop-cock
I used PTFE on both threads of the stop-cock and wound it clockwise, so when the nut is done up, it takes the PTFE *with it*
I also PTFE'd the olive but i cant remember if i did it clockwise or anti-clockwise.
Thinking it through now, it would seem to make sense to PTFE the olive *anti-clockwise* so again, the clockwise turning of the nut takes the olive and PTFE with it....make sense ?

I don't believe that i am over-tightening the nuts

So my questions are :

1. PTFE the threads necessary (y/n) and if so, clockwise or anti or doesn't matter ?
2. PTFE the olives necessary (y/n) and if so, clockwise or anti or doesn't matter ?
3. Don't use PTFE but Boss White on the end of the copper pipe instead ?
4. Use PTFE and use Boss White also ?
5. Olives....copper or brass or doesn't matter ?

I would really appreciate knowing how others prep a compression to ensure no leaks so look forward to seeing the replies

TIA


BTW, i used one of the Philmac fittings as suggested on this forum (akethalene to copper push-fit). Could it be as good as all the hype....

WOW....a great piece of kit....thoroughly recommended !!!!

 

[Newboy]

Don't use PTFE on compression fittings.

A smear of sealant on the joint if needs be.

 

[JohnD]

I used PTFE on both threads of the stop-cock

Why?

Where do you think the water seal is, on a compression joint?

It's the olive that has to seal, not the nuts.

PTFE is one of the ways of doing it.

Some people prefer other ways.

 

[Newboy]

PTFE is one of the ways of doing it.

The wrong way of doing it - how does PTFE tape assist the olive to seal into a profiled face on a compression fitting?

Some people prefer other ways

Anybody who knows what they're doing (and gets paid for doing it).

If you're feeling in the 'PTFE is good for compression fittings' mood again contact the following and ask how to make a compression joint:

https://www.pegleryorkshire.co.uk/EN/ContactUs/UKContacts
http://www.conexbanninger.com/product_range.php?brands_id=7
https://www.ciphe.org.uk/

 

[JohnD]

does PTFE tape assist the olive to seal into a profiled face on a compression fitting?

Yes. But if you're convinced that plumbers' joints never leak (ha ha!) and that PTFE joints always do (ha ha ha!) then good luck, hold on to your opinion.

 

[Newboy]

Well, despite my own rule of not feeding trolls, here goes.....


How exactly does PTFE tape assist the seal between the olive and the machined face of the compression fitting?

 

[oldbuffer]

By filling in minute imperfections if the interface between the olive and the fitting. In essence, using PTFE on the olives is no different from using a sealant. The tape fills the minute gaps, just as the Boss White of Jet Lube V2 do.

If you have new fittings and new olives, they are generally well enough made that tightening the joint "squashes" the metal enough to eliminate gaps. However, on re-used olives / fitting, this may not be enough, and "belt and braces" suggests the use of a sealant, whether paste or PTFE.

 

[Newboy]

I'm not suggesting that stuffing a compression fitting full of tape doesn't stop a leaky joint (in the same way that pouring Radweld into a car cooling system stops it leaking).

I'm simply pointing out that PTFE is a sticking plaster - a properly made joint doesn't need PTFE and a joint that benefits from PTFE needs making again - properly

 

[JohnD]

yes, I know the anti-PTFE routine that old plumbers trot out:

- compression joints work perfectly and have no gap
- you just put paste in to fill the gap
- all right, so there is a gap, but I don't like PTFE
- they never leak
- and you only put PTFE on the olive when they do leak
- all right, so PTFE does stop them leaking, but they never leak so you shouldn't use PTFE
- and anyway, people who use PTFE might wrap it round the pipe, the threads, the doorknob and the bathtaps, so it looks unsightly, and that's a reason why you should never put PTFE on an olive. Except to make a good seal that doesn't leak. And I never do that because my joints never leak. Except sometimes when they do

That's fine with me. I never use PTFE, except on joints that I don't want to leak.

 

[Dan Robinson]

people who use PTFE might wrap it round the pipe, the threads, the doorknob and the bathtaps, so it looks unsightly, and that's a reason why you should never put PTFE on an olive

It is actually handy to identify when an idiot has been trying to work on the plumbing and helps forewarn a professional that more muppetry may be lurking.

 

[Hot&Cold]

Sean H welcome to the world of plumbing please remember people who have done 1000's of compression joints will know how the joint is going to end up before final testing.Its called experience and not available via ebay-amazon.

if your unsure of your work just periodically examine it. Additional insurance is usually available for diy mishaps but check your existing provider .

diy work has its limitations

 

[JohnD]

I'm sure no pipe installed by a professional plumber has ever leaked.






In Narnia.

 

[dilalio]

I'm sure no pipe installed by a professional plumber has ever leaked.






In Narnia.

Been at the back of many wardrobes not discovered any entrance to Narnia though.

 

[shd1970]

Sean H welcome to the world of plumbing please remember people who have done 1000's of compression joints will know how the joint is going to end up before final testing.Its called experience and not available via ebay-amazon.

if your unsure of your work just periodically examine it. Additional insurance is usually available for diy mishaps but check your existing provider .

diy work has its limitations

thanks for the reply old&cold

I've done a number of compressions (i'm not a novice) from replacing all the radiators in my house, new Mira shower so fitted isolations, new feed for upstairs toilet etc but then i will do a compression be it a stop-cock on this occasion which as i say, has a slight weep so i wanted to gauge just what steps everyone else goes through but it seems like everything, everyone has their own
I prepare for compression fittings like i would a solder joint.....cut pipe, deburr and then clean the pipe that will be inserted. It only takes 2 mins so no harm done.
I agree there is probably no point in PTFE'ing the threads but its not going to break the bank but from the olive perspective, it seems there are those that PTFE it, newboy who uses sealant (not sure how that would work personally as wouldn't it need to go off for 24hrs before you could test it ?) and i guess others who don't use anything

Obviously as its a new stop-cock, i want to make sure its solid so i dont have to turn the water off in the road and also, empty the system again if at all possible

So if this were you, can you confirm what you would do please in terms of :

• PTFE the threads necessary (y/n) and if so, clockwise or anti or doesn't matter ?

• PTFE the olives necessary (y/n) and if so, clockwise or anti or doesn't matter ?

• Don't use PTFE but Boss White on the end of the copper pipe instead ?

• Use PTFE and use Boss White also ?

• Olives....copper or brass or doesn't matter ?

Thanks in advance and to any other plumber who is willing to share their preparation steps

 

[Newboy]

PTFE the threads necessary (y/n) and if so, clockwise or anti or doesn't matter ?

No - the threads are not providing the seal in a compression fitting

PTFE the olives necessary (y/n) and if so, clockwise or anti or doesn't matter ?

No - the olive tightening against the pipe and into the fitting provide the seal

Don't use PTFE but Boss White on the end of the copper pipe instead ?

Personally I prefer Water Hawk (blue for potable water) - a smear on the face of the fitting

Olives....copper or brass or doesn't matter ?

I prefer copper but either will do the job