how to test gas copper line for leaks

We need to test a gas copper line for leaks and we're currently using water at about 115 psi and a pressure gauge, but I am not sure this is the right approach.

I'd like to ask what is the standard procedure to test a gas copper line for leaks.

Is water or air used?

At what pressure?

For how long?

What would be an acceptable drop in pressure in this period of time?

Can an unexpensive pressure gauge ($15 or so) be used with water or air?

Thanks a lot in advance.

Reply to
renux
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Where I live (AZ) the gas is delivered to the residence at ~ 11 ounces of pressure. We do not use copper for gas lines, black iron and galvanized are the choices we have. Tests are done with air at 30 psi. No leaks for 24 hours.

What does the AHJ want you to do?

What does the utility supply and what do they recommend?

Reply to
SQLit

One older technician for our local gas company goes around to each joint with a match. I like to use soapy water. You can also put a tee in the line with a Schrader valve and use an electronic tire pressure gauge. Any pressure drop is not acceptable. DO NOT put water inside the tubing.

Reply to
Bob

Copper??? Too soft to use. If you want to sweat those together with ANY gas in there good luck!

Galvanized or Black Pipe is the way to normally go for Natural gas.

Reply to
BocesLib

I don't think he said natural gas.

Reply to
Bob

Ok, maybe you'd rather sweat copper with propane in there? ;-)

Reply to
Keith Williams

He didn't say anything about sweating copper either.

Reply to
Bob

Propane is often done with copper, mostly compression fittings. As for sweating with propane in it, yes, it can be done. No., it won't explode. All of our natural gas lines in commercial and industrial are welded. Yes, they are sometimes welded with gas in them, but the meter shut off.

Reply to
Edwin Pawlowski

Did you mean flare fittings?

Reply to
Bob

Yeah, them things you tighten with a wrench.

Reply to
Edwin Pawlowski

We use butane and "type L" copper, which is thicker than normal copper for water.

I am told that type L copper is ok for gas as long as the pipe is safe from being hit, and with the advantage that copper is more resistent to corrosion. If the pipe is exposed to physical damage, then galvanized should be used.

I called my local AHJ, and they pointed me to an official norm that states to use twice the normal-use pressure for 30 min.

They also pointed me to a certified expert, which I am actually going to hire to do the testing.

Thanks every body that responded. Your advice was very helpful!

Cheers

Reply to
renux

Around here, copper can be used with propane or natural gas. It is not allowed to have sweated fittings, nor compression fittings, they all must be flared. The copper must be flexible, not sure of the grade, but it is the thicker wall pipe.

Reply to
EXT

I saw a wench once.

Reply to
Bob

Type L is normally used for water lines also. Type M is used for hydronic heat. If you already pressure tested that gas line with water, then you should tell "certified expert".

Reply to
Bob

A long time ago, the only thing you could use for natural gas was black iron pipe. Years ago, gas suppliers started putting an additive in the gas that made the use of copper ok, but some local codes were never changed.

Reply to
Bob

They make a test gauge for gas it has a 3/4 female pipe thread the body has a gauge attached and a Schrader (sp) valve for a bicycle pump. 15 psi is normal for residential in my area. I would pump it up and soap the joints. I can't remember the Time to hold pressure. The PSI can vary From area to area Type of line welded . Check Local Codes. Remember it's gas so you want to do it right. test gauge

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3/4" FPT Hex-Body

Reply to
Sacramento Dave

I remember when only black iron was allowed. The switch to copper came in our area when the utility (which I worked for) decided to use copper lines from the underground to the meter because there was less damage to the service from frost heaving. The copper would just bend a bit where the black iron elbows and couplings on the meter could crack or pull loose with solid iron pipe.

Reply to
EXT

Your forgot to mention something the original poster is unaware of. They tested the pipes BEFORE they buried them.

Bill

Reply to
Berkshire Bill

When I was in Arizona they pressurized to 14 psi and waited 24 hours. Here in Tennessee, they turn on the propane and soap the joints. If the house is still there 20 minutes later, they figure it's ok.

Bob

Reply to
RobertM

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