I have recently extended some pipework using compression fittings. It had
been suggested to me that I should not over tighten the fitting as the olive
could cut into the pipe. Now I have notice on a couple of the fittings that
whilst they appear water tight there seems to be a powery deposit forming
round where the pipe goes into the fitting. It suggests to me that I have
not tightened them correctly but would appreciate any feedback.

Thanks

David - Milton Keynes

"David Klyne" wrote in message
...
I have recently extended some pipework using compression fittings. It had
been suggested to me that I should not over tighten the fitting as the
olive
could cut into the pipe. Now I have notice on a couple of the fittings
that
whilst they appear water tight there seems to be a powery deposit forming
round where the pipe goes into the fitting. It suggests to me that I have
not tightened them correctly but would appreciate any feedback.


If they are watertight then leave well alone!

In an earlier contribution to this discussion,
David Klyne wrote:

I have recently extended some pipework using compression fittings. It
had been suggested to me that I should not over tighten the fitting
as the olive could cut into the pipe. Now I have notice on a couple
of the fittings that whilst they appear water tight there seems to be
a powery deposit forming round where the pipe goes into the fitting.
It suggests to me that I have not tightened them correctly but would
appreciate any feedback.
Thanks

David - Milton Keynes

Water *has* been leaking very slowly - and had probably immediately
evaporated, so you won't have seen any liquid - but it has left this
deposit. The original leak may well have silted up and cured itself. Try
cleaning the fittings with wire wool, and see whether the deposit
re-appears.
--
Cheers,
Roger
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In article ,
"David Klyne" writes:
I have recently extended some pipework using compression fittings. It had
been suggested to me that I should not over tighten the fitting as the olive
could cut into the pipe. Now I have notice on a couple of the fittings that

The olive has to cut into the pipe -- that's part of the water
tight seal. You can overdo tightening though and deform the pipe
or olives to the point where they can seal anymore.

whilst they appear water tight there seems to be a powery deposit forming
round where the pipe goes into the fitting. It suggests to me that I have
not tightened them correctly but would appreciate any feedback.

Yes (or overtightened). Really you should undo the joint to
clean out the crud rather than risking tightening crud into the
water sealing surfaces.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
David Klyne wrote:
I have recently extended some pipework using compression fittings. It
had been suggested to me that I should not over tighten the fitting as
the olive could cut into the pipe. Now I have notice on a couple of the
fittings that whilst they appear water tight there seems to be a powery
deposit forming round where the pipe goes into the fitting. It suggests
to me that I have not tightened them correctly but would appreciate any
feedback.

A correctly tightened compression fitting should have the ring compressed
so that it can't be removed from the pipe easily. And you'd have to use a
deal of force to overtighten one. So not easily done with the correct
spanners. You'd have to be using extra long types.

IMHO most give problems because of damage to the pipe in some way -
linear scratches being a favourite cause by the pipe being pushed through
some small hole etc. That's the beauty of a soldered joint - if the pipe
and fitting are cleaned properly solder will fill any such small
irregularities.

--
*Be nice to your kids. They'll choose your nursing home.

Dave Plowman London SW
To e-mail, change noise into sound.

On Sun, 13 Jan 2008 09:53:13 +0000 (GMT) someone who may be "Dave
Plowman (News)" wrote this:-

A correctly tightened compression fitting should have the ring compressed
so that it can't be removed from the pipe easily. And you'd have to use a
deal of force to overtighten one. So not easily done with the correct
spanners. You'd have to be using extra long types.

Indeed. So far I have yet to over-tighten one, though no doubt that
day will come. I don't hold the end of spanners and then swing on
them as some people do.



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

"Dave Plowman (News)" wrote in message
...
In article ,
David Klyne wrote:
I have recently extended some pipework using compression fittings. It
had been suggested to me that I should not over tighten the fitting as
the olive could cut into the pipe. Now I have notice on a couple of the
fittings that whilst they appear water tight there seems to be a powery
deposit forming round where the pipe goes into the fitting. It suggests
to me that I have not tightened them correctly but would appreciate any
feedback.

A correctly tightened compression fitting should have the ring compressed
so that it can't be removed from the pipe easily. And you'd have to use a
deal of force to overtighten one. So not easily done with the correct
spanners. You'd have to be using extra long types.

IMHO most give problems because of damage to the pipe in some way -
linear scratches being a favourite cause by the pipe being pushed through
some small hole etc. That's the beauty of a soldered joint - if the pipe
and fitting are cleaned properly solder will fill any such small
irregularities.

If the pipe and fitting have been cleaned properly (wire wool and a wipe, no
scratches), a compression joint will be just as fine! You can get away
without cleaning a soldered joint as well (with powerful flux), true, but
they're the same if properly cleaned.

I once heard that plumbers "never fully tightened compresssion joints
because, if there's a leak they still have something to tighten".

It is also true that , for a properly tightened compression joint (finger
tight then 1/4-1/2 a turn), you won't get the olive off.

Don't forget to clean the olive as well as the pipe/fitting.


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)