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Gas connection Solder or Compression?
Surrey Dave - 18/5/07 at 06:55 PM

If I where to fit a copper 22mm pipe onto my old gas barrel pipe , (which I wouldn't 'cos it's illegal).

Does it have to be soldered at the 1st joint , I have an adaptor that screws onto the old pipe and has acompression fitting for the new copper?


JoelP - 18/5/07 at 06:57 PM

compression fittings on gas pipes must be accessible. Threaded fittings need gas paste on both sides. Do you know how to pressure test the system? Worth buying a U tube if you do intend to fiddle with it.


coozer - 18/5/07 at 07:02 PM

Solder, then a pressure/leak test.


Chippy - 18/5/07 at 07:09 PM

Soldered fitting on gas are NOT acceptable, all fittings MUST be compression. I think that it has something to do with the natural gas having a detrimental effect on solder, (in other words they leak). As far as I am aware, (may be wrong), but you are perfectly legal in carrying out work on your own gas instalation, but would recommend that you have a CORGY reg'd fitter check it afterwards. This is how it used to be, may have changed since I was involved with it, but somebody will come along soon and give the word according to the present law. Ray


JoelP - 18/5/07 at 07:19 PM

not so mate, solder is fine. Just be sure, if soldering, to use a flux that isnt acid based, since unlike water pipes it will never be washed out.


owelly - 18/5/07 at 07:20 PM

Oh dear! I have installed tons of gas gear with soldered copper.........
As previous, all comp fitting must not be hidden or buried. Soldered are fine as far as I'm concerned.


Chippy - 18/5/07 at 07:27 PM

OK so I'm wrong, but thats what it used to be, but haven't been involved with gas fitting for, Erm! zzzzzz years. Ray


Surrey Dave - 18/5/07 at 07:33 PM

Yes I will have it checked by a CORGI person

Are we saying I can use compression fittings all the way on the gas , as long as I use the correct gas fitting paste ?

What is the paste called?

As I understand it there is a permitted amount of pressure drop from the meter to the appliance , what is it and how do I measure it with a u tube.


JoelP - 18/5/07 at 07:44 PM

you dont have to worry about pressure drop in my limited experience, so long as you pick the right size pipe and the length isnt excessive. Gas paste isnt needed on compression fittings, i meant literal threaded fittings like onto a hob etc.

what are you fitting? Pick either 22mm for a boiler or 15mm for most other things and you will *probably* be ok on pressure.


millenniumtree - 18/5/07 at 07:56 PM

Ok, so I read this whole thread and when I got to the last post, I sat there for a second and then thought to myself...

"You stupid yank, GAS means NATURAL GAS".
You'd be talking about petrol otherwise... Durrrr...

In the states, as far as I know, you can NOT use soldered connections in a gas line. Must be threaded black steel or compression fittings.

When your house starts on fire and the solder melts... Big boom.

We had a small leak in our gas line when we bought the house - they bodge fixed it with JB Weld or similar. Then I put some plastic pipe hangers on the 5m of pipe in the basement that was totally unsupported...

Did I mention the previous owners were clueless?? They lived there 30 years and didn't get around to fixing the most basic, and most dangerous things.

Sewer gas in the basement, open electrical boxes with guts hanging out, unsupported leaky gas lines, main water supply literally spraying all over the wall... Basement nightmare!!


flak monkey - 18/5/07 at 09:17 PM

Soldered gas fittings are fine as Joel says. The gas main into our house is all soldered and was installed to Corgi standards *cough*.

Our gas fire and hob are run off 15mm pipes, the boiler has a 22mm one IIRC. It was 10 years or so ago they were fitted.

David


Deckman001 - 18/5/07 at 10:26 PM

Dave, give Paul (gasgasgas) a u2u about it, he's a free agent now so can do any testing you need done, he's fully corgi'd, but is on Hols as of this weekend for two weeks

Jason


MkIndy7 - 18/5/07 at 11:41 PM

quote:
Originally posted by Surrey Dave
Are we saying I can use compression fittings all the way on the gas , as long as I use the correct gas fitting paste ?

What is the paste called?

As I understand it there is a permitted amount of pressure drop from the meter to the appliance , what is it and how do I measure it with a u tube.


Either compression or solider fitting are fine provided compression are exposed and vented or the Flux is cleaned off afterwards if soldiered (massive problem on new build properties!).

The Paste is called Gas Paste.. or any that says it is suitable for use on Natural Gas on the Label (presuming it isin't LPG)

The permitted pressure drop is 1mbar, it must be atleast 21mbar running pressure when tested at the meter with the U Guage on the test nipple and atleast 20mbar WITH the appliance running when tested at the inlet (test Nipple) of the appliance (usually its own gas valve).

Hope that helps, ( I am CORGI registered not just guessing!)


Surrey Dave - 19/5/07 at 12:20 AM

Thanks for the info.