# Gas pressure test



## Rambo (Aug 29, 2010)

your gonna have to furnish the gauge and compressor...just the new work needs to be tested...you should of added a gas cock on your new branch so you could isolate it from the rest of the main...so now your gonna have to test the whole system unless you take it back apart or cut and thread and add a union and gas cock at the T....

here the pressure needs to be half the gauge and hold...i usally test then leave and go back after the inspection is done...


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## the_man (Aug 14, 2010)

If you have valves on the gas lines to the other appliances, you can shut em off and test easier so you don't have to cut in a valve on the new work. If I remember right its 15 psi air test for 30 minutes. Like the dude above said the gauge is supposed to be twice the test pressure, leave the test on for a couple hours just in case there are any problems


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## NHMaster (Dec 21, 2009)

2 and 1/2 times working pressure and yes, you will be required to test the entire system.


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## braindead (May 31, 2010)

I know you don't want to ask the inspector, but you have to. You need to know how much pressure he requires and how long you have to leave it on, you can't test against another appliance, they have to be valved off and capped, that includes the furnace.


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## joside (Mar 24, 2010)

braindead said:


> I know you don't want to ask the inspector, but you have to.


I think you missed when I wrote: "I realize these are questions for the inspector, and I'll ask him, but I just want to prepare myself."

I did ask him yesterday when I passed my HVAC/plumbing/electric rough-in:thumbup: and here's what he told me:

I only need to test the new part of the system. I need to get 10psi to hold for about 15-30 minutes (depending on how bored the inspector gets, I guess). The gauge is $10 at Home Depot, and it has a Schrader valve so I can just use my bike pump. He said put the gauge on one end and cap off the other. Then I can just attach the new pipe back into the system using a union as long as that union is accessible later (not inside a wall). My other option is to use a reverse threader piece and coupler so I can tighten the pipe inline.

I thought I'd post this as a reference to others, but keep in mind my inspector might be very different from yours.


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## NHMaster (Dec 21, 2009)

Fortunately ( or rather unfortuantely ) for you, your inspector is ignorant. Only hold for 10 to 15 minutes? (so is it ok if it leaks after 30 minutes) It's gas. Gas has a nasty habit of removing houses from their foundations. So are you happy with 10 to fifteen minutes? 

GAS PIPING, VALVES AND FITTINGS MUST HOLD PRESSURE......FOREVER :thumbsup:

10 lbs is not an accurate leak test. I said before, 2.5 times working pressure and the gauge can't be a 2 dollar HD water pump gauge. You need a Rogers gauge ( or similar ) or a manometer. Only a proper pressure and gauge will detect very small leakage which can and often does turn into a big BOOM

I'm sure that you decided to take on the piping project because you thought that hiring a pro to do it would cost too much. Now you know why it cost so much. It's because the pro would know the proper way to install and test reqardless of the expertese of the inspector. A pro would know that the entire system needs to be capped off and tested. A pro would know that the test would be performed at 2.5 times working pressure and a pro would have the 150 dollar gauge necessary to properly test the system. 

Good luck with your project. Sleep well :wink:


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## fireguy (May 3, 2007)

NHMaster said:


> Fortunately ( or rather unfortuantely ) for you, your inspector is ignorant. Only hold for 10 to 15 minutes? (so is it ok if it leaks after 30 minutes) It's gas. Gas has a nasty habit of removing houses from their foundations. So are you happy with 10 to fifteen minutes?
> 
> GAS PIPING, VALVES AND FITTINGS MUST HOLD PRESSURE......FOREVER :thumbsup:
> 
> ...


NH Master plumber forget one minor thing, a licesenced pro will have liability insurance to protect himself and you against mishaps. Does your homeowners insurance cover you if you make a mistake?


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## braindead (May 31, 2010)

joside: I didn't miss what you said, I was just commenting on the fact that no matter what the forum said you would have to get your final answer from the inspector. :yes:


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## braindead (May 31, 2010)

*Gas Test*

NHMaster: I don't want to start a pizzing contest, but some of your statements don't compute:

...10 lbs is not an accurate leak test. I said before, 2.5 times working pressure...

Since most residential systems run on 1/2psi a 10 lb. test is 20 times working pressure.

...Fortunately ( or rather unfortuantely ) for you, your inspector is ignorant...

The inspector has to do the test the way his jurisdiction wants it, not the way someone on the job thinks it should be done; that dosen't make him ignorant.

...Only hold for 10 to 15 minutes?...

A good gage will tell you instantly if you have a leak in the system, i.e. mercury, (which most areas will not allow anymore).

Used to test major systems with 6in of mercury, which comes out to 3psi, even under your figures a 2lb. system would only be checked to 5lb.

...GAS PIPING, VALVES AND FITTINGS MUST HOLD PRESSURE......FOREVER...

Does that mean that you can never take the test off? :huh:


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## NHMaster (Dec 21, 2009)

No, what it means is that you need to get a copy of the National Fuel Gas Code and read the section on gas pipe testing ( so does your local inspector )

Gauges accurate enough to detect a very slow leak will not handle 10 lbs pressure, and are very expensive.

Look, I'm not busting your chops here, I'm trying to keep your house on the foundation. The Nat. gas code has everything you need to know about gas pipe testing. I'm licensed for gas service and installation in three states and I don't give a crap what the inspector wants in any case. I care what the code says and what will cover my ass legally. 10lbs on a 4 dollar pressure gauge does not meet those requirements.


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## the_man (Aug 14, 2010)

I gotta say i agree with NHMaster, if you have to ask that many questions you're probably not ready to do it. Too many things can go wrong, and you can't put a bucket underneath one of those leaks :no:


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## joside (Mar 24, 2010)

This is getting comical. Dude, I understand you're a professional but I think you're missing some things here. Braindead pretty much hit the nail on the head but to reiterate:

10psi is well over 20 time the allowed gas pressure for the furnace.

"...GAS PIPING, VALVES AND FITTINGS MUST HOLD PRESSURE......FOREVER..." What exactly is that supposed to mean? I have to test it "forever"?

Also, it's not a "water pump gauge". It's a gas gauge, the increments are in tenths.

Not to burst your bubble, but I wasn't asking for your professional opinion on my local inspector. I can sleep perfectly fine, as I have for years, using pipe dope and tightening the crap out of my pipes. My question was simply about passing the inspection.


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## NHMaster (Dec 21, 2009)

No, what is comical, actualy a tragic comedy, is that you do not have a clear understanding of what I am telling you, and unless you are willing to invest a few years of your life and get some training, you never will. But for the sake of the show I'll say it again. Gas piping gets testeed at 2.5 times working pressure. Testing it at 20 lbs tells you nothing and is not necessary. Unless you spent in the neighborhood of a hundred dollars or so that "gas" gauge you have is not worth spit. But, you naturally, know more than a guy with 36 years experience in the trade and the licenses and certs to back it up. So for the final act, keep on keeping on and we'll all be here for the grand finale' Hopefully you will also. :laughing:

(Quote)Not to burst your bubble, but I wasn't asking for your professional opinion on my local inspector. I can sleep perfectly fine, as I have for years, using pipe dope and* tightening the crap out of my pipes.* My question was simply about passing the inspection. 

You ought to re-think that sentence
As far as your inspector goes. do whatever he want's from you. After all he's a licensed professional gas technician too.... isn't he?


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## kenmac (Feb 26, 2009)

code states 1.5 x the max working pressure, but not less than 3 psig . test not to exceed 24 hrs...Around here , inspectors require 10 psig for 10 min.


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## joside (Mar 24, 2010)

NHMaster said:


> But, you naturally, know more than a guy with 36 years experience in the trade and the licenses and certs to back it up.


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.


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## kenmac (Feb 26, 2009)

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


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## NHMaster (Dec 21, 2009)

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. :laughing:


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## joside (Mar 24, 2010)

NHMaster said:


> 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. :laughing:


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...:whistling2:


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## NHMaster (Dec 21, 2009)

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 (Mar 24, 2010)

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?


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## NHMaster (Dec 21, 2009)

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 (Oct 11, 2010)

*Gas line pressure test*

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?


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## NHMaster (Dec 21, 2009)

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


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## weldman (Oct 8, 2010)

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


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## rhclayto (Nov 17, 2010)

NHMaster said:


> 10 lbs is not an accurate leak test. I said before, 2.5 times working pressure and the gauge can't be a 2 dollar HD water pump gauge. You need a Rogers gauge ( or similar ) or a manometer. Only a proper pressure and gauge will detect very small leakage which can and often does turn into a big BOOM


But the IRC states:
---

*§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.
---

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.


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## fireguy (May 3, 2007)

NHMaster said:


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


 
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.


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## NHMaster (Dec 21, 2009)

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 (Mar 15, 2009)

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.


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## the_man (Aug 14, 2010)

COLDIRON said:


> 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.
> 
> ...


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 :laughing:


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## kenmac (Feb 26, 2009)

fireguy said:


> 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.


 

I use ball valves & haven't had any problems


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## Ltnicks (Nov 9, 2010)

I was brought up on the torch technique, there are better ways that I have learned.

wondering if this "pro" with 36 years of experience cares to post his/her license number and certifications to back up the arrogant posts.

if you say you are who you are then all that is left is that you, sir, lack tact, it sounds as if you can memorize words from a code book but don't understand its reasoning or the science that mandates a code in any profession.

let's not let this hack of a professional wreck the image of all of us.


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## NHMaster (Dec 21, 2009)

kenmac said:


> I use ball valves & haven't had any problems


we are not talking gas shut off valves here, we are talking about the gas control valve itself, the one on the appliance.


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## NHMaster (Dec 21, 2009)

Ltnicks said:


> I was brought up on the torch technique, there are better ways that I have learned.
> 
> wondering if this "pro" with 36 years of experience cares to post his/her license number and certifications to back up the arrogant posts.
> 
> ...


Tell you what, why don't you post your address, phone number and social security number? :laughing:

You mistake arrogance for knowledge and caution. How much tact is required when folks that obviously have no experience with gas service are bound and determined to forge ahead anyway?

Yes, I have memorized many words from many code books. Mostly because I teach code to plumbers, gas technicians and oil burner technicians. Are you telling us that knowledge of the code is a bad thing?

What "image" do you have? The guy that tests for gas leaks with a torch?:laughing: give it time, those eyebrows will grow back in :thumbsup:


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## Ltnicks (Nov 9, 2010)

I ask you to back up your empty statement of license and certifications, and you answer with this



NHMaster said:


> Tell you what, why don't you post your address, phone number and social security number? :laughing:


this is a statement of someone with no license 



NHMaster said:


> Yes, I have memorized many words from many code books. Mostly because I teach code to plumbers, gas technicians and oil burner technicians. Are you telling us that knowledge of the code is a bad thing?


knowledge and memorizing are two different things. if you need me to explain everything to a so called teacher to


NHMaster said:


> I teach code to plumbers, gas technicians and oil burner technicians.


then you have bigger problems and you should be the one learning from the students



NHMaster said:


> What "image" do you have? The guy that tests for gas leaks with a torch?:laughing: give it time, those eyebrows will grow back in :thumbsup:


Im the guy with real world experience:thumbsup:


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## NHMaster (Dec 21, 2009)

Ltnicks said:


> I ask you to back up your empty statement of license and certifications, and you answer with this
> 
> 
> 
> ...


 
Experience at what? setting fire to yourself :laughing:


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## COLDIRON (Mar 15, 2009)

NHMaster said:


> Tell you what, why don't you post your address, phone number and social security number? :laughing:
> 
> You mistake arrogance for knowledge and caution. How much tact is required when folks that obviously have no experience with gas service are bound and determined to forge ahead anyway?
> 
> ...


:laughing::laughing::laughing::laughing::laughing:
You all know what they say, "Those who can't do it teach it"


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## NHMaster (Dec 21, 2009)

Cept that I've been "doing it" for 30 odd years now as well as teaching. Besides which, I would like for somebody to explain how you teach something like plumbing and HVAC without knowing how to do it? And, this is a DIY site where folks come for advice. How useful whould that advice be if it only came form other DIY'ers that have no clue what the code is or what the accepted way to do it is? I hve said this before and I'll repeat it again. I have no problem with helping a guy out with problems that are not going to potentially put themselves, their families and their neighbors in jeopardy. Gas work of any kind should only ever be done by licensed, qualified service technicians.


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## Emergency (Dec 11, 2017)

How much is the going rate for a gas line air test? We have a leak, the Gas company came out and couldn't locate the leak. They shut off our gas and told us to call a plumber and get the gas lines "air tested". They said "after the plumber locate and repair the leak, call them and they will turn the gas back on. I live in Detroit, MI, our home is 110 years old and we have lived here for 50 years. I would like to have some idea of the cost. Your opinion would be greatly appreciated. Women are often over charged.


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## COLDIRON (Mar 15, 2009)

This is an old posting from 2009. Just sayin.


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## Ghostmaker (Mar 2, 2013)

joside said:


> I think you missed when I wrote: "I realize these are questions for the inspector, and I'll ask him, but I just want to prepare myself."
> 
> I did ask him yesterday when I passed my HVAC/plumbing/electric rough-in:thumbup: and here's what he told me:
> 
> ...


That differs by gas supplier in my area.


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## hkstroud (Mar 17, 2011)

> How much is the going rate for a gas line air test?


Call a local plumbing company and ask if they have plumbers with gas license. 
Ask cost.



> Women are often over charged.


Unfortunately that often true. Maybe you could have a male friend act for you.


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## LeakyMike (Oct 14, 2009)

NHMaster said:


> 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.


WoW!! and they are receptive to you telling them they don't know their jobs?

In real life the code is what an inspector says it is. They're are perfectly competent DIYers out there as well as hack contractors with licences. Not speaking about you but it's not an all or nothing game.


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## hkstroud (Mar 17, 2011)

WOW!!! is correct. Did anyone read what the last poster(Emergency) ask? She ask for advice about getting a fair price for a gas line test. 

Why does everyone want to rehash a 8 year old post?


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## SeniorSitizen (Sep 10, 2012)

hkstroud said:


> Why does everyone want to rehash a 8 year old post?


Because as DIY'ers they have plenty to do that needs doing but are procrastinating and how could that be as much fun as rehashing old posts.


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