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Mike Armstrong
 
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Default Undoing and re-making soldered copper pipe...

Hi all,

I'm fitting my new boiler this weekend.

In order for the gas supply pipework to be sufficiently sized I am
replacing the final section of 15mm with 22mm.

The 22mm pipe runs under the concrete floor, through a swept bend
vertically up the wall to about 500mm from the floor where it is
reduced by a soldered 22-15 reducing connector to 15mm pipe. it
continues from here to the boiler.

The original installer has hacked a channel in the plasterboard
dry-lining and the pipe is set into this channel with a few mm
clearance to the blockwork wall behind.

This is all going on behind by kitchen units and I have created an
access hole to get at the joint.

I would normally cut the pipe and use a 22mm connector to extend the
22mm pipework, however access is extremely difficult. There is little
or no flex in the pipe to use my pipe splitter and the fact that it is
recessed behind the plasterboard makes using a hacksaw pretty
impossible.

I am wondering whether it would be easier to apply heat to the
reducing connector to 'un-make' the joint. The question is how hard
is it to clean up the 'un-made' end in preparation for the new 22mm
straight-through connector?

Once cleaned up would another soldered joint be necessary?
Compression would be easier!


Cheers!


Mike
  #2   Report Post  
BigWallop
 
Posts: n/a
Default


"Mike Armstrong" wrote in message
...
Hi all,

I'm fitting my new boiler this weekend.

In order for the gas supply pipework to be sufficiently sized I am
replacing the final section of 15mm with 22mm.

The 22mm pipe runs under the concrete floor, through a swept bend
vertically up the wall to about 500mm from the floor where it is
reduced by a soldered 22-15 reducing connector to 15mm pipe. it
continues from here to the boiler.

The original installer has hacked a channel in the plasterboard
dry-lining and the pipe is set into this channel with a few mm
clearance to the blockwork wall behind.

This is all going on behind by kitchen units and I have created an
access hole to get at the joint.

I would normally cut the pipe and use a 22mm connector to extend the
22mm pipework, however access is extremely difficult. There is little
or no flex in the pipe to use my pipe splitter and the fact that it is
recessed behind the plasterboard makes using a hacksaw pretty
impossible.

I am wondering whether it would be easier to apply heat to the
reducing connector to 'un-make' the joint. The question is how hard
is it to clean up the 'un-made' end in preparation for the new 22mm
straight-through connector?

Once cleaned up would another soldered joint be necessary?
Compression would be easier!

Cheers!

Mike


Gas pipework must be soldered, especially if fitted in an un-accessible
position, Mike. Compression joints on permanent gas pipes are not the way
to go unless you can get at them easily.


  #3   Report Post  
Andrew Gabriel
 
Posts: n/a
Default

In article ,
Mike Armstrong writes:
Hi all,

I'm fitting my new boiler this weekend.

In order for the gas supply pipework to be sufficiently sized I am
replacing the final section of 15mm with 22mm.

The 22mm pipe runs under the concrete floor, through a swept bend
vertically up the wall to about 500mm from the floor where it is
reduced by a soldered 22-15 reducing connector to 15mm pipe. it
continues from here to the boiler.

The original installer has hacked a channel in the plasterboard
dry-lining and the pipe is set into this channel with a few mm
clearance to the blockwork wall behind.

This is all going on behind by kitchen units and I have created an
access hole to get at the joint.

I would normally cut the pipe and use a 22mm connector to extend the
22mm pipework, however access is extremely difficult. There is little
or no flex in the pipe to use my pipe splitter and the fact that it is
recessed behind the plasterboard makes using a hacksaw pretty
impossible.

I am wondering whether it would be easier to apply heat to the
reducing connector to 'un-make' the joint. The question is how hard
is it to clean up the 'un-made' end in preparation for the new 22mm
straight-through connector?


Redoing a joint like this which was done OK originally is not difficult.
You don't have to clean the pipe end up, just make sure the pipe end is
tinned all the way round (i.e. that it was a good joint originally).
You might not be able to push the coupler over the solder. In this case,
you will have to heat the pipe end in order to push the cleaned/fluxed
coupler on, and then heat the joint as normal until solder flows and add
a little more to make up for that lost in the reducer.

Redoing a joint when the original was not OK is harder, and would require
the pipe end to be cleaned up (and a new fitting as it's generally not
worth cleaning up an old one which failed to solder correctly in the
first place).

Once cleaned up would another soldered joint be necessary?
Compression would be easier!


Not allowed for gas in an inaccessible or confined space.
Are you sure you are competent to do the gas side?
Don't forget to do a soundness test before and after (so you know if
you've introduced a leak, and/or if there was originally a leak which
you need to go and find).

--
Andrew Gabriel
  #4   Report Post  
Mike Armstrong
 
Posts: n/a
Default

On 13 Jan 2005 17:01:21 GMT, (Andrew
Gabriel) wrote:

In article ,
Mike Armstrong writes:


snip
I am wondering whether it would be easier to apply heat to the
reducing connector to 'un-make' the joint. The question is how hard
is it to clean up the 'un-made' end in preparation for the new 22mm
straight-through connector?


Redoing a joint like this which was done OK originally is not difficult.
You don't have to clean the pipe end up, just make sure the pipe end is
tinned all the way round (i.e. that it was a good joint originally).
You might not be able to push the coupler over the solder. In this case,
you will have to heat the pipe end in order to push the cleaned/fluxed
coupler on, and then heat the joint as normal until solder flows and add
a little more to make up for that lost in the reducer.

Redoing a joint when the original was not OK is harder, and would require
the pipe end to be cleaned up (and a new fitting as it's generally not
worth cleaning up an old one which failed to solder correctly in the
first place).


The joint is OK. I did a pressure drop test when fitting our gas fire
last week.

So the procedure would be :-

1. Heat existing reducer and remove (with tongs!)
2. Cleaing and flux the new 22m pipe end
3. Clean and flux _both_ ends of inside of new 22mm connector
4. Mate new pipe and new connector ready to heat.
5. Heat old pipe end to soften existing solder
6. While still hot, lower new assembly onto pipe and continue to heat
until joint is made, adding extra solder if necessary.

Clearly, I will be carrying out another soundness test on completion.


Once cleaned up would another soldered joint be necessary?
Compression would be easier!


Not allowed for gas in an inaccessible or confined space.
Are you sure you are competent to do the gas side?
Don't forget to do a soundness test before and after (so you know if
you've introduced a leak, and/or if there was originally a leak which
you need to go and find).


  #5   Report Post  
Cicero
 
Posts: n/a
Default


snipped

Redoing a joint like this which was done OK originally is not difficult.
You don't have to clean the pipe end up, just make sure the pipe end is
tinned all the way round (i.e. that it was a good joint originally).
You might not be able to push the coupler over the solder. In this case,
you will have to heat the pipe end in order to push the cleaned/fluxed
coupler on, and then heat the joint as normal until solder flows and add
a little more to make up for that lost in the reducer.

Redoing a joint when the original was not OK is harder, and would require
the pipe end to be cleaned up (and a new fitting as it's generally not
worth cleaning up an old one which failed to solder correctly in the
first place).

snipped

Andrew Gabriel


================
Does it matter if the solder types are different? On the rare occasions
that I've had to do as the OP is doing I've always cleaned off the old
solder completely to avoid any incompatability.

Cic.




  #6   Report Post  
Andy Wade
 
Posts: n/a
Default

Andrew Gabriel wrote:

Redoing a joint like this which was done OK originally is not difficult.
You don't have to clean the pipe end up, just make sure the pipe end is
tinned all the way round (i.e. that it was a good joint originally).
You might not be able to push the coupler over the solder. In this case,
you will have to heat the pipe end in order to push the cleaned/fluxed
coupler on, [...]


When you get the old joint apart, wipe the end of the pipe with a
slightly damp cloth while the solder is still molten (use a swift
motion, to avoid cooling things down). This will remove surplus solder
and leave a nice clean tinned end for the new joint. It's similar to
cleaning the tip of a soldering iron on a damp sponge.

--
Andy
  #7   Report Post  
Junior Member
 
Posts: 9
Default

Yes you can solder the old off, clean it up with sandpaper, and put the new one back on - with solder, finish it off, and check with fairy liquit for leages, or even with a lighter (yes i actually have seen them doing that- though I wouldn't recommand it)

Well if you space it limited, it is also dificult to put a compression on it, so that is then ruled out,

To cut the pipe there are these nice round 22mm cutter that only need about a 1,5cm clearance arround the pipe

Success
  #8   Report Post  
StealthUK
 
Posts: n/a
Default


Andy Wade wrote:
Andrew Gabriel wrote:

Redoing a joint like this which was done OK originally is not

difficult.
You don't have to clean the pipe end up, just make sure the pipe

end is
tinned all the way round (i.e. that it was a good joint

originally).
You might not be able to push the coupler over the solder. In this

case,
you will have to heat the pipe end in order to push the

cleaned/fluxed
coupler on, [...]


When you get the old joint apart, wipe the end of the pipe with a
slightly damp cloth while the solder is still molten (use a swift
motion, to avoid cooling things down). This will remove surplus

solder
and leave a nice clean tinned end for the new joint. It's similar to


cleaning the tip of a soldering iron on a damp sponge.

--
Andy


Yep, the only thing that normally hinders a new coupler going on is a
lip of solder at the end of the pipe. I also just heat the end of the
pipe and wipe round with a cotton cloth, although not damp in my case.

  #9   Report Post  
 
Posts: n/a
Default


StealthUK wrote:
Andy Wade wrote:
Andrew Gabriel wrote:

Redoing a joint like this which was done OK originally is not

difficult.
You don't have to clean the pipe end up, just make sure the pipe

end is
tinned all the way round (i.e. that it was a good joint

originally).
You might not be able to push the coupler over the solder. In

this
case,
you will have to heat the pipe end in order to push the

cleaned/fluxed
coupler on, [...]


When you get the old joint apart, wipe the end of the pipe with a
slightly damp cloth while the solder is still molten (use a swift
motion, to avoid cooling things down). This will remove surplus

solder
and leave a nice clean tinned end for the new joint. It's similar

to

cleaning the tip of a soldering iron on a damp sponge.

--
Andy


Yep, the only thing that normally hinders a new coupler going on is a
lip of solder at the end of the pipe. I also just heat the end of the
pipe and wipe round with a cotton cloth, although not damp in my

case.


If the joint is in a tight place and or tight up against a wall then a
heat resitant mat might help. It takes the concentration of fitting a
joint like this way from the flames that are burning the wall.

  #10   Report Post  
Junior Member
 
Posts: 22
Default

read your boiler insructions
I cant think of any domestic boilers that require 22mm supply
unless the pipework is a very long way from the meter and has lots of bends ,
you will need to get your work checked , please dont turn the gas back on until a tightness test has been done .


  #11   Report Post  
Simon Stroud
 
Posts: n/a
Default


"Andy Wade" wrote in message
...
Andrew Gabriel wrote:

Redoing a joint like this which was done OK originally is not difficult.
You don't have to clean the pipe end up, just make sure the pipe end is
tinned all the way round (i.e. that it was a good joint originally).
You might not be able to push the coupler over the solder. In this case,
you will have to heat the pipe end in order to push the cleaned/fluxed
coupler on, [...]


When you get the old joint apart, wipe the end of the pipe with a
slightly damp cloth while the solder is still molten (use a swift
motion, to avoid cooling things down). This will remove surplus solder
and leave a nice clean tinned end for the new joint. It's similar to
cleaning the tip of a soldering iron on a damp sponge.

--
Andy


ISTR that the instrument of choice in the old BT or probably PO lead cable
jointing days was a moleskin rather than a damp cloth!

Not sure if they keep those down at B&Q!

Good luck.
Simon.


  #12   Report Post  
Senior Member
 
Posts: 174
Default

Quote:
Originally Posted by Mike Armstrong
Hi all,

I'm fitting my new boiler this weekend.

In order for the gas supply pipework to be sufficiently sized I am
replacing the final section of 15mm with 22mm.

The 22mm pipe runs under the concrete floor, through a swept bend
vertically up the wall to about 500mm from the floor where it is
reduced by a soldered 22-15 reducing connector to 15mm pipe. it
continues from here to the boiler.

The original installer has hacked a channel in the plasterboard
dry-lining and the pipe is set into this channel with a few mm
clearance to the blockwork wall behind.

This is all going on behind by kitchen units and I have created an
access hole to get at the joint.

I would normally cut the pipe and use a 22mm connector to extend the
22mm pipework, however access is extremely difficult. There is little
or no flex in the pipe to use my pipe splitter and the fact that it is
recessed behind the plasterboard makes using a hacksaw pretty
impossible.

I am wondering whether it would be easier to apply heat to the
reducing connector to 'un-make' the joint. The question is how hard
is it to clean up the 'un-made' end in preparation for the new 22mm
straight-through connector?

Once cleaned up would another soldered joint be necessary?
Compression would be easier!


Cheers!


Mike

Obviously you shouldn't be doing this at all, because if you were qualified to you wouldn't be asking the question. Howver let me point out a few obvious mistakes which would fail you on your pipework practical during ACS assessment.

1/ Before we solder a gas pipe we cap off the meter (best not just to disk it, put a proper cap on it or remove it completely and turn it upside down or put something suitable over the two holes to prevent the gas escaping, without which there is a very real danger of explosion. This explosion could easily cause a mortal injury and damage to property.

2/ Connect temporary earth bond upstream first then downstream and then break into the pipe.

A pre tinned pipe from an old joint is the very best basis of a new joint.

Make sure you use correct solder.

Most boilers today require 22mm gas pipe.

Pipe sizing is another subject but certainly manufacturers specify 22mm minimum, without which they likely won't honour a guarantee.

Like I say you shouldn't do the gas work, but if you are determined to you'd better learn a bit more about it or we'll be watching your house on news at 10.
  #13   Report Post  
Markus Splenius
 
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Default

On Thu, 13 Jan 2005 18:54:34 +0000, Andy Wade
wrote:

When you get the old joint apart, wipe the end of the pipe with a
slightly damp cloth while the solder is still molten (use a swift
motion, to avoid cooling things down). This will remove surplus solder
and leave a nice clean tinned end for the new joint. It's similar to
cleaning the tip of a soldering iron on a damp sponge.


When I used to do electronics, we used to use desolder braid. Fine
stranded wire that what "suck" up the solder. I don't know if it would
work in a plumbing situation - you'd probably need a wide guage!

M.

  #14   Report Post  
Capitol
 
Posts: n/a
Default



Mike Armstrong wrote:

6. While still hot, lower new assembly onto pipe and continue to heat
until joint is made, adding extra solder if necessary.


Do this joint first, soldering uphill is a recipe for problems.

Regards
Capitol
  #15   Report Post  
BigWallop
 
Posts: n/a
Default


"Simon Stroud" wrote in message
...

"Andy Wade" wrote in message
...
Andrew Gabriel wrote:

Redoing a joint like this which was done OK originally is not

difficult.
You don't have to clean the pipe end up, just make sure the pipe end

is
tinned all the way round (i.e. that it was a good joint originally).
You might not be able to push the coupler over the solder. In this

case,
you will have to heat the pipe end in order to push the cleaned/fluxed
coupler on, [...]


When you get the old joint apart, wipe the end of the pipe with a
slightly damp cloth while the solder is still molten (use a swift
motion, to avoid cooling things down). This will remove surplus solder
and leave a nice clean tinned end for the new joint. It's similar to
cleaning the tip of a soldering iron on a damp sponge.

--
Andy


ISTR that the instrument of choice in the old BT or probably PO lead cable
jointing days was a moleskin rather than a damp cloth!

Not sure if they keep those down at B&Q!

Good luck.
Simon.


A decent chamois leather is good. It's also good at doing smooth wiped
joints on lead pipework as well, wet or dry.




  #16   Report Post  
Andy Dingley
 
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Default

On Thu, 13 Jan 2005 23:01:15 -0000, "Simon Stroud"
wrote:

ISTR that the instrument of choice in the old BT or probably PO lead cable
jointing days was a moleskin rather than a damp cloth!


Moleskins for soldering need to be made from good cotton moleskin and
lubricated with tallow. Proper moleskin works a lot better than even
denim or corduroy. I've been trying lots of different fabrics lately
as lead-wiping moleskins, cotton, linen, wool, even Kevlar and
asbestos. You can't beat the traditional stuff.

And yes, I have even tried using Mole. I really don't recommend that.

  #17   Report Post  
John Rumm
 
Posts: n/a
Default

Tony wrote:

I cant think of any domestic boilers that require 22mm supply


A good number do... anything over 30kW will need 22mm for a good
proportion of the pipe run unless it is very close to the meter.

unless the pipework is a very long way from the meter and has lots of
bends ,


See here for information on pipe sizing:

http://www.cda.org.uk/megab2/build/p...0Tube%20Sizing



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/
  #18   Report Post  
Mike Armstrong
 
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On Thu, 13 Jan 2005 16:26:06 GMT, Mike Armstrong
wrote:

snip

Thanks for all the replies to my question. Clearly re-soldering is
the way to go.

For peace of mind can I state that:-

I have calculated the pipework sizing requirements (this is why the
15-22 change is needed)

I _will_ be disconnecting the gas pipework from the meter and clearing
the gas from said pipework.

The pipework _will_ be earth bonded while the work takes place.

Once coplete the pipework will be tested for soundness using pressure
drop test (at 20mb and also 5 and 10 looking for pressure rise to
ensure that no gas is leaking past the shut-off lever)

The gas pipe will be be fully purged.


Thanks again for all your help.


Mike
  #22   Report Post  
Senior Member
 
Posts: 174
Default


Woh, 5 to 15% and under tests it always explodes at 9%. I only learned the 9% thing yesterday from a former pit deputy. I had been called to his boiler which wouldn't light. On inspection the ht lead was burnes away, when I lit the pilot by hand there was a strong smell of gas. This turned out to be coming from an idadequatley fitted Bundy Tube. Plenty of soot showed that under certain conditions this escape was igniting and burning away the ht lead.

I was doing my speach about how easy it would be for a build up of 5% and boom, when he said, you don't need to tell me mate, and went on to give his story. They used to run regular tests and always the explosion occured at 9%. It must be that we are tought 5 to 15 because there is a remote chance of explosion either side of the 9%. Of course we all know that concentrations would vary around the room.

Anyhow he was very pleased to get it sorted, more so than most people, and I learned something too.
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