# Gas Pipe Pressure Testing?



## Ironlight (Apr 13, 2011)

Here in DC the building inspector needs to see a gauge, on the terminus of the line (where the flex line would be attached) that shows the line pressurized. I don't think the line needs to be purged before it is pressurized...gas is gas, a leak does not care whether it is natural gas or air. 

This I think is a new requirement for close-in inspection because my plumber was not familiar with it. I don't recall what he psi he pressurized the line to and I can't find reference to it anywhere by Googling although I seem to recall seeing the gauge standing at 20 psi. But he left the gauge on for the inspector to see so it was there for at least 48 hours. He used a Husky bicycle pump to pressurize the line.


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## jamm51 (Sep 27, 2011)

Correct about meter. Disconnect flex and attach guage. You should use the correct fitting for this. Gauge is not special. The one I use is incremented in 2 psi increments. Any shut off valves at appliances should be disconnected and the pipe capped. Do not test through a shut off valve. After all of the new pipe is capped, with a test gauge at one end, pump it up to around 15 psi. It has to hold with no more than a few psi drop for ten minutes. Those numbers could vary with different areas, inspectors.
Basically, they want to see pressure holding steady for ten or fifteen minutes. 
Remember, the pressure after the meter, going to appliances, is only a few ounces. Like 1/2 a pound. So if it holds 15 or 20 psi for ten minutes, it's good to go.
The inspector is going to check that the pipe is capped, that it has pressure, and holds it. 

And that the pipe is properly supported, clamped.
Usually, he will look at gauge, release a pound or so of pressure to check that the gauge works, walk around and check everything is capped, come back to check pressure is where it was, put the green sticker on the pipe and you're done.
Make sure it is ready and pressurized when he gets there.
After, remove caps and hook up. Usually the gas company is then called by inspector and they will come turn gas on and check for leaks at flex lines (where you had caps on )
Did you put drip tubes in at each appliance?

No purging or evacuating of air required. When it is filled with gas and valve opened to appliance to light it, the air will come out.


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## jamm51 (Sep 27, 2011)

Reread your post. Unions are not recommended. Very hard to seal. You just have to reef on them. Use couplings if possible. Hope you didn't use teflon tape. Grey pipe dope better. 
Go get a test fitting. 3/4" male pipe thread on one end. Schraeder valve ( like bicycle tube valve ) on the other end. Psi gauge threaded into top


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## nahfootball (Nov 29, 2011)

Thanks for the help, so I'm pretty sure I got the few answers I was looking for. I already picked up the gauge and such from the local plumbing supplier yesterday after posting, I'll give it a whirl today. Have a good one!

Yes, I use pipe dope, yes, each appliance has a sediment/drip trap, yes, I understand compression unions are not ideal and if I were to do the original install years and years ago I would've avoided it haha, but they didn't and I would've fought to get a regular coupler based on the other lines in the house.


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