On Tuesday, 21 February 2017 19:21:39 UTC, Harry Bloomfield wrote:
tabbypurr brought next idea :

3 plumbing joints done with ptfe tape all leak. I mostly don't use ptfe to
seal joints. 2 of the joints are 15mm compression tee (with one male end, one
female end) onto an extension piece, the other is extension piece onto brass
threaded ballcock. 1.5 turns of yellow/gas ptfe tape each, all neatly in
place. I admit to not being clear how the nut would seal to the tee it's on.
The one joint done with fibre washer & gloop works fine of course, but I
don't think that approach can be used with the other joints.

Compression joints should not need anything else to seal them, the
olive is supposed to deform to make the seal between fitting and nut
and the pipe. The pipe end should go well into the fitting, to keep
things aligned.

the joints in question don't have an olive. They're screw threaded extensions to compression fittings. The tape goes on the screw thread.

And yes, I do use gloop on compressions, old pipe does not seal reliably without.


NT