Is it safe to run natural gas through copper tubing that has been sweated together?

Question

Or should it be flared fittings only?

Answer 1

Typically plumbing codes call for flare fittings.

Obviously all fittings need to be checked for leaks after assembly, using a soap solution.

If you have a leaker, and the fitting has been sweated together, you've got yourself a problem. You certainly don't want to take a torch to it at that point.

I suspect it is because the need to use flame in sweated fittings, and the fact that gas is flammable, is the reason codes call for flare fittings.

Natural gas is not very corrosive. It is very dry and corrosion is normally caused by the presence of water at the delivery temps of Natural Gas.

The best approach is to install per code. You could have insurance problems with a non-code installation. You don't want to take a chance of voiding homeowner's insurance over a savings of perhaps $10.

Answer 2

The key is a sound joint. Copper that's sweated will usually suffice for water, but may not be all that advisable for gas. Seeing as it's difficult to adequately test sweated joints, and given the potential harm should such a joint fail, I think I'd rather use a more substantial means of joining pipe. Around here, it's illegal for anyone not certified to lay gas pipe, either as a main service route or into any building where the gas will be burned. I had gas service installed just this year to replace my oil burning furnace, and there's no copper within the house - and those who worked on both sides of the service entrance were required by the state of New York to be certified. That might be your safest approach...

Answer 3

Copper piping is acceptable per National Plumbing Code. It can be sweat joints but must be brazed using minimum 15% silver rod and NOT soft soldered. Type L copper must be used. It also can be flared mechanical joints. There are better options though using corrugated stainless steel which is much easier to run.
I've installed 4" copper gas piping in buildings in Washington DC.

Answer 4

in the unites states, copper is not recommended for natural gas.

there is a product called CSST that is a flexible stainless steel that can be used in its place. contact the gas company to find a supplier. You MUST preform a pressure test before the gas can be turned on. the gas company will likely do this for you for a minimal charge.

remember, even if an arabic terrorist burns the house down, if the insurance company finds out that you messed with the gas lines, they will still blame you for the fire

Answer 5

Here the UK copper is used for nearly all domestic use of both natural gas & LPG and lasts for at least 60 years and is not corrosive.In the UK it is illeagle for unqualified persons to work on any gas pipe or aplliance. Natural gas is very explosive and dangerouse if fitted by unscilled persons.The fact that you needed to ask the question indicates you are unscilled. Stay well away, you or others could be killed.
UK C.O.R.G.I registered engineer

Answer 6

Let me make it simple for you. It is against code to run gas thru soft drawn copper. The kind you buy in rolls. However it is ok to run it thru hard drawn copper. This is the kind you buy in sticks. Here in STL it is prefered for residential to use copper instead of black pipe. You must keep in mind you MUST braze the joints not soft solder. As a fitter myself I ran miles of copper for gas lines. We use nitrogen to check for leaks. good luck and be careful

Answer 7

You should Not use copper at all for Nat. gas. Just don't do it, it will corrode your pipe, flare isn't good because it's still copper. It's ok for LP but not Nat. gas.

Answer 8

Natural gas would corrode copper pipes over time.

Answer 9

Yes, though most codes require silver solder. Some solder is suspected of being corroded by the additives in the gas.

Answer 10

Black pipe is the industry standard. You don't want to take a chance on a pressurized flammable gas explosion, or a code violation for that matter!