How do I pressure check gas lines and what device do I use?

A brush and a small container of water with enough soap in it that it will form bubbles if you apply the soapy water to a pressurized joint where there's a leak.

Make sure there is plenty of ventilation and no ignition sources until you're certain your work is leak free

Hi Hjeffereson:

First... really need to know what you are testing and why.. But I will give a basic breakdown to get you started! Testing gas pipe is not quite as simple as stated by RobertVA....ok?

In my area (Massachusetts) we are required to test our gas pipes by pumping the gas system with AIR to 3PSI and to hold that test for 15 minutes... BUT we must use a special 5LB pressure test gauge (see picture). It reads PSI in 1/10th degree increments.

My point here is that some areas also require a 10LB or even a 25LB test and no special gauge... just a 25 or 50LB pressure gauge without appreciable drop in 1 hour, for example. So, you may want to check to see what local code requires in your area... ;)

Anyway, idea to test entire gas SYSTEM is to isolate all gas valves and the meter from harm from excessive test pressure... Here, you need to shut all shutoffs to each appliance in the home (we actually break the union at each appliance and cap the pipe at each appliance if testing entire system). We will also drop or SPIN the meter out of the way and CAP the meter outlet (if not could damage the diaphragm inside the meter) OR install the test gauge and perform the test at the meter.

If leak is detected via test gauge then SOAP solution is used to find small leaks and then they are repaired. Pipes are retested, inspection is called, and then rehook all and all set!

If just testing one line or one shutoff and 5-10 feet of piping may be able to test from the shutoff forward without going through all this... BUT BE CLEAR HERE... that if excess pressure hits the system... even by mistake you could blow a gas valve or even the meter.. so be careful!

Let us know a little more about what you are doing exactly!! See if we can help isolate the test procedure a bit.

MARK

And after all that you have to disturb the meter connection when you rotate it back into the normal position, make a new untested connection between the meter and the building and make new untested connections between the cutoff(s) and appliance(s) where you had them capped off. Then you start a new round of tests with only the soapy water as a resource (remember that the test gauge has been removed from the system by then).

All that when HJefferson528 was probably just wanting to connect the flexible supply line on his new kitchen range or outdoor grill, both of which wouldn't be connected during that gauge test anyway.

At the risk of sounding like a pessimist, it ooks like the plumber's lobbyists have gotten to the senior codes and inspection bureaucrats.

We in So.California test our (rigid) gas lines at 10 PSI for 10 minutes. We use 15 lbs gauge. We test Poly gas pipe and Trac gas pipe at 60 PSI for 10 minutes.

Have same question as Mark: Why?

Anyways: to check your house gas system, you have to disconnect all gas appliances and gas fixtures. Remove all gas valves . They hold only 3-5 PSI of pressure and would leak during test giving you false reading. Then, disconnect your gas main on the RIGHT side of your gas meter. Install gauge. Take bicycle pump and pressurize to desired PSI. Reading should remain same after 10 minutes.

Hjefferson528 - I agree with Mass plumber and Milo Dolezsal. First of all do check with the local GAS CO. In this part of Tenn. The pressure test is 5#( LBS - for 15 min. and a inspector has to come out and check it also. BUT WE disconnect at the right side of the meter, take the line comeing from the house ,off at the coustomer side of meter, put on pressure gaudge pump up and test. If after 15 min. it showes there is a leak them we go to the soapy water, and startt testing and looking to see if were blowing bubbles some where, then we repair the leak, and do a retest all over again,until we have NO loss in pressure. Good luck And GOD BLESS ( NOTE - STAY SAFE < FOLLOW ALL Safety PRACTACES ::: F.B.E.