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  #1   Report Post  
Nodge
 
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Default Compression joint leaking

Just been doing a bit of plumbing in the bathroom. I've fitted a 15mm
isolator valve in the feed to the wc. I suspect the copper pipe is the old
imperial 1/2" dia but I understood that the 15mm fitting would be ok. I've
tightened the nut on the isolator valve as much as I dare but I've still got
a small leak. It seems to be coming from between the pipe and the nut rather
than from the threads of the nut. (I put PTFE tape around the thread).
What's the best way to get a watertight seal?

Nodge


  #2   Report Post  
Dave Jones
 
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"Nodge" wrote in message
...
Just been doing a bit of plumbing in the bathroom. I've fitted a 15mm
isolator valve in the feed to the wc. I suspect the copper pipe is the old
imperial 1/2" dia but I understood that the 15mm fitting would be ok. I've
tightened the nut on the isolator valve as much as I dare but I've still
got
a small leak. It seems to be coming from between the pipe and the nut
rather
than from the threads of the nut. (I put PTFE tape around the thread).
What's the best way to get a watertight seal?

Nodge


PTFE tape should be put around the olive not the thread, after all it's the
olive that seals.

Dave Jones


  #3   Report Post  
Set Square
 
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In an earlier contribution to this discussion,
Dave Jones wrote:

"Nodge" wrote in message
...
Just been doing a bit of plumbing in the bathroom. I've fitted a 15mm
isolator valve in the feed to the wc. I suspect the copper pipe is
the old imperial 1/2" dia but I understood that the 15mm fitting
would be ok. I've tightened the nut on the isolator valve as much as
I dare but I've still got
a small leak. It seems to be coming from between the pipe and the nut
rather
than from the threads of the nut. (I put PTFE tape around the
thread). What's the best way to get a watertight seal?

Nodge


PTFE tape should be put around the olive not the thread, after all
it's the olive that seals.

Dave Jones


I know that people *do* put PTFE tape round olives - even though it's really
meant for sealing tapered thread joints. For difficult compression joints, I
prefer a smear of Boss White or Plumbers Mait round the olive.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.


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Peter
 
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"Nodge" wrote in message
...
Just been doing a bit of plumbing in the bathroom. I've fitted a 15mm
isolator valve in the feed to the wc. I suspect the copper pipe is the old
imperial 1/2" dia but I understood that the 15mm fitting would be ok. I've
tightened the nut on the isolator valve as much as I dare but I've still

got
a small leak. It seems to be coming from between the pipe and the nut

rather
than from the threads of the nut. (I put PTFE tape around the thread).
What's the best way to get a watertight seal?

Nodge


Did you use PTFE around the olive ?


  #5   Report Post  
Harry Bloomfield
 
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Default

Nodge formulated on Sunday :
Just been doing a bit of plumbing in the bathroom. I've fitted a 15mm
isolator valve in the feed to the wc. I suspect the copper pipe is the old
imperial 1/2" dia but I understood that the 15mm fitting would be ok. I've
tightened the nut on the isolator valve as much as I dare but I've still got
a small leak. It seems to be coming from between the pipe and the nut rather
than from the threads of the nut. (I put PTFE tape around the thread).
What's the best way to get a watertight seal?


Copper olives are best used where an old imperial pipe is to be
connected to, copper has more 'give' than the usual brass olives.

--


--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.org



  #6   Report Post  
Nodge
 
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"Peter" wrote in message
...

"Nodge" wrote in message
...
Just been doing a bit of plumbing in the bathroom. I've fitted a 15mm
isolator valve in the feed to the wc. I suspect the copper pipe is the

old
imperial 1/2" dia but I understood that the 15mm fitting would be ok.

I've
tightened the nut on the isolator valve as much as I dare but I've still

got
a small leak. It seems to be coming from between the pipe and the nut

rather
than from the threads of the nut. (I put PTFE tape around the thread).
What's the best way to get a watertight seal?

Nodge


Did you use PTFE around the olive ?



No, I only put the tape on the thread. I'll try unscrewing the nut and
putting tape on the olive. I would think this would only give a seal between
the mating surfaces of the nut, valve body and the olive. I suspect the leak
is between the olive and the copper pipe.
Nodge


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mike ring
 
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"Nodge" wrote in
:

Just been doing a bit of plumbing in the bathroom. I've fitted a 15mm
isolator valve in the feed to the wc. I suspect the copper pipe is the
old imperial 1/2" dia but I understood that the 15mm fitting would be
ok. I've tightened the nut on the isolator valve as much as I dare but
I've still got a small leak. It seems to be coming from between the
pipe and the nut rather than from the threads of the nut. (I put PTFE
tape around the thread). What's the best way to get a watertight seal?

Compression joints don't require anything at all; I use a bit of grease on
the moving parts, and they shouldn't need a terrible lot of tightening.

Worst case - you may have a deformed pipe, (and you may have just deformed
it) in which case a new bit will have to be inserted, or replace the run if
reasonable.

It may have been a faulty olive; the olive certainly will be faulty by now!
Try again with a new olive. (You can buy them separately, in case you
weren't aware)

mike

  #8   Report Post  
Brian Reay
 
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"Harry Bloomfield" wrote in message
...
Nodge formulated on Sunday :
Just been doing a bit of plumbing in the bathroom. I've fitted a 15mm
isolator valve in the feed to the wc. I suspect the copper pipe is the

old
imperial 1/2" dia but I understood that the 15mm fitting would be ok.

I've
tightened the nut on the isolator valve as much as I dare but I've still

got
a small leak. It seems to be coming from between the pipe and the nut

rather
than from the threads of the nut. (I put PTFE tape around the thread).
What's the best way to get a watertight seal?


Copper olives are best used where an old imperial pipe is to be
connected to, copper has more 'give' than the usual brass olives.


That is a good idea!

Another thing to look for is a scratch / groove along the pipe under the
olive- enough to give a slow leak (been there etc).

Don't use PTFE tape on compression joints, a bit of "boss white" or "hawk
white" is OK. Also make sure the mating surfaces are clean and undamaged.

(Oh, and Harry is another radio amateur lurker. This group is full of us!)

--
Brian Reay
www.g8osn.org.uk
www.amateurradiotraining.org.uk
FP#898


  #9   Report Post  
Andrew Gabriel
 
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In article 0,
mike ring writes:

It may have been a faulty olive; the olive certainly will be faulty by now!
Try again with a new olive. (You can buy them separately, in case you
weren't aware)


Reminds me -- standing in a plumbers merchant, dressed in suit for
wedding, whilst we try dropping olives on the floor. You'll find a
22mm brass olive gives the best impression of a gold wedding ring
for bounce and sound, if you're the best man and you intend to pull
a stunt where you drop the wedding rings on the floor at the last
moment (not the real ones, obviously). Copper ones don't sound
right, and aren't the right colour. 15mm ones sound too tinny,
and the audience at the back might not see them so well.

--
Andrew Gabriel
  #10   Report Post  
Dave Plowman (News)
 
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Default

In article ,
Set Square wrote:
I know that people *do* put PTFE tape round olives - even though it's
really meant for sealing tapered thread joints. For difficult
compression joints, I prefer a smear of Boss White or Plumbers Mait
round the olive.


Try Fernox sealer. It's the dog's dangly bits - works on any mixture of
materials I've tried. Pricey but worth every penny.

--
*I'm out of my mind, but feel free to leave a message.

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


  #11   Report Post  
Dave Plowman (News)
 
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In article ,
Nodge wrote:
No, I only put the tape on the thread.


The thread has no sealing effect on a compression fitting.

I'll try unscrewing the nut and putting tape on the olive. I would think
this would only give a seal between the mating surfaces of the nut,
valve body and the olive. I suspect the leak is between the olive and
the copper pipe.


The seal is between the olive and the pipe, and the tapers on the ends of
the olive and the corresponding ones on the fitting. If there is any
damage to these - deep scratches etc, it won't seal. Worth also looking at
the tapers on the fitting to make sure they have actually been machined -
I've come across one that wasn't.

--
*You sound reasonable......time to up my medication

Dave Plowman London SW
To e-mail, change noise into sound.
  #12   Report Post  
Nodge
 
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I checked again this morning and it seems to have stopped leaking. Maybe the
olive compressed a little more overnight.
I think I'll leave well alone and see how it goes.

Nodge


  #13   Report Post  
Andrew Gabriel
 
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In article ,
"Nodge" writes:
I checked again this morning and it seems to have stopped leaking. Maybe the
olive compressed a little more overnight.
I think I'll leave well alone and see how it goes.


That's also one of the few benefits of hard water. Normally takes
a few days for it to seal up a slow dripping joint though.

--
Andrew Gabriel
  #15   Report Post  
Owain
 
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Default

"mike ring" wrote
| Reminds me -- standing in a plumbers merchant, dressed in
| suit for wedding, whilst we try dropping olives on the floor.
| Also helps to have a few spares when you drop the real ring
| down the crypt

Or when the bride's got swollen knuckles from a catfight at the hen night
and it's a shame to cut the real ring so it slides over the bruises.

Of course, you don't have to marry a Glasgow lass.

Owain


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