Gas pressure test

joside

Good lord, I have no idea why people like you bother even posting on DIY websites. Look, I understand more than you think but I appreciate that you are a 36 year "gas technician" so please explain this to me. You ARE on the website to answer questions right? You keep talking about "working pressure" without being specific. From what I (and several other people here) understand, the working pressure of a residential gas meter is a fraction of a PSI. So testing the system at 10psi should be more than enough. Are you suggesting that it should be tested at around .75psi (about 2.5 times the working pressure at my meter)? I promise, I'm not being sarcastic this time, I actually want to know if you have a good reason it should be tested at a much lower pressure than everyone else thinks.

I've talked to several contractors and plumbers as well as done some more searching on the web and 10psi for about 15 minutes seems to be what is done everywhere. Again, I am not questioning your credentials, but why do you think a pressure test should require a manometer? If it is a very slow leak, I suppose it's hard to tell with a less accurate gauge but mine has been holding pressure for 2 weeks now.

If you are correct and pressure tests should require manometers, than why don't cities or insurance companies require this? Yes, I was being facetious before but I was trying to make the point that most people just install their pipes very tightly, do the soap test and call it good. I am, however, doing a pressure test not just because it's required, but because it's a good idea.

From the California Plumbing Code
1214.1.4 Where new branches are installed from the point of delivery to new appliances, only the newly installed branches shall be required to be pressure-tested.

1214.3.1 Mechanical gauges used to measure test pressures shall have a range such that the highest end of the scale is not greater than five
times the test pressure.

1214.3.2 The test pressure to be used shall be no less than 1-1/2 times the proposed maximum working pressure, but not less than 3 psi

1214.3.3 When testing a system having a volume less than 10 cubic feet (0.28 m3) or a system in a single-family dwelling, the test duration shall be a minimum of 10 minutes.

I'd love to add to this with the actual NFGC text but I don't feel like paying $50 to view the pdf.

kenmac

In my neck of the woods. gas pressure test for residental is 10# for 10 min & we use a 15-30# spring guage

NHMaster

I post on sites like this to keep people like you from blowing your house off it's foundation and spreading the remains all over other folks lawns and generally taking down property values in the area.

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joside

Once again, not answering my questions, just mocking me with violent rhetoric. I'll be thinking of you next time I'm plunging a toilet...

NHMaster

I did answer you, a couple of times at that and you just don't seem to understand the concept of testing, so why continue to beat the horse? If you are happy and your hack inspector is happy than keep on keeping on.

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joside

No you have not answered my questions. Specifically, why do you think a system should be tested at .75psi (per your own claim of 2.5 times the working pressure) when the California Plumbing Code states a minimum testing pressure of 3psi? If you believe the working pressure of a residential gas line is greater than about .3psi, please explain why this is the case. Additionally, why do you think a manometer is required when the code also states that a mechanical gauge can be used?

If you think I'm misreading the code, than explain yourself. If you think the code is not safe enough, than say so, but it's not my "hack inspector" who insists upon this, it's literally every inspector in the state of California. Everyone else who has posted here disagrees with you and that is why I continue to "beat the horse". I have no reason to doubt you are a qualified gas technician and I would like to understand your position. I am not, however, going to accept the answer that I need "to invest a few years of your life and get some training." If that is your answer than I ask again, why do you bother posting on DIY sites?

NHMaster

Ok, here it is again; When you test at low pressures, using either a manometer or an expensive gauge ( Rodgers ) any leak, no matter how small will show up. At higher pressures it is very hard for the guage to get an accurate reading.

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TEEKAY

Tee'd black pipe from existing install to kitchen for new gas range.

I have a 2lb supply system.

I was reading the data sheet that came with the .05 lb pressure regulator i installed and it says nominal inlet pressure is 7-9lbs....so-o-o I take it that means i can only pressure test up to 9 lbs without blowing it up?

NHMaster

You don't want to put pressure on the gas valve at all.

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weldman

I dont sweat it. I tighten the heck out of the pipes that have good threads. dope and gas tape both.
Then on goes the gas, then i brush on dish soap/water everyday for a few days.

done

rhclayto

But the IRC states:
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§G2417.4.1 (406.4.1) Test pressure. The test pressure to be used shall not be less than one and one-half times the proposed maximum working pressure, but not less than 3 psig (20 kPa gauge), irrespective of design pressure. Where the test pressure exceeds 125 psig (862 kPa gauge), the test pressure shall not exceed the value that produces a hoop stress in the piping greater than 50 percent of the specified minimum yield strength of the pipe.

§2417.4.2 (406.4.2) Test duration. The test duration shall not be less than 10 minutes.
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2.5 times working pressure of 1/2 psi (1.25 psi) actually contradicts the IRC requirement of a minimum 3 psi test.

Most residential gas work is done according to codes similar to the IRC. It is your contention that this is inadequate, & will have dangerous consequences. So the real question becomes, is there real evidence that testing according to the IRC (or similar) requirements in a residential environment results in any statistically significant number of explosions or fires? That sort of evidence would make your Chicken-Little bluster something more than obnoxious.

H.

fireguy

Why does a gas valve leak at the test pressure? I thought a gas valve was rated at 600 PSI WOG, 150 PSI WSP. I do not install the gas appliance shut off until after the inspector OKs the test.

And I always ask the inspector what pressure and what length of time he wants.

NHMaster

I never ask an inspector what pressure or time he wants. If he want's anything other than what I am giving him then he does not know his job.

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COLDIRON

NOT RECOMMENDED. I knew a guy about 40 years ago that installed gas lines and when the job was complete he would turn on the gas and run a lighter over all the joints, any leaks would show up immediately it would light up at the leak just like a lighter.

He's gone now for several years he had a heart attack.

Never blew any thing up, guess he was lucky. Oh! me to I used to watch him.

DO NOT TRY THIS EVER.

the_man

haha an old journeyman of mine did this, i always thought he was nuts. i've done it once or twice, but never without a valve in sight. i've also seen the gas company guy light a cigarette when he came out to shut off a main hit by the backhoe. we all ran...very fast