On 21/02/2017 20:08, newshound wrote:
On 2/21/2017 7:36 PM, Chris Green wrote:
wrote:
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.


I'm clearly making a basic mistake here. Did I mention I don't like
plumbing?

Well basic mistake one to my mind is using PTFE tape with compression
joints. PTFE and compression joints don't mix - where did you put the
tape anyway?

Although this is the conventional wisdom, IMHO it is always worth
putting PTFE tape on the threads because it reduces the friction
coefficient. So you get more axial force for a given torque. It's the
axial force which makes the seal.

Wisdom says use a proper lubricant.

Lubricant doesn't creep like PTFE.

PTFE is intended for taper threads.

Whenever I see PTFE tape on a compression fitting you can always tell
it's a rank amateur.

In practice you can supply more than enough force to a compression
fitting to destroy an olive, such there ought not be any need for lubricant.