Best way to detect a leaking gas line?

[mdk0420]

Hello. I'm installing a gas line running from the meter to my combi boiler. I've been tackling some leakage here and there as I work on other things for the project. The gas line is ran all the way to the boiler itself. I popped a cap on it and wanted to leave it pressurized until the inspector gets out here because if I don't lose any air by then, there is no chance I'm getting a leak.

When I pressurized it I've found a couple of leaks, one being where the end cap is where there were damaged threads on the nipple (Got a replacement and no leaks now), and the other on the pressure gauge female end that screws into my gas line. I got about a 2-3 PSI drop in a couple of hours when I went to test this. I tested with the leak detector stuff on all the fittings and pretty much instantly the two spots mentioned started bubbling up and I tightened them down.

I re-pressurized the system to 15 PSI and it has been about 24 hours and I lost 1 PSI. I went to test them all and I'm not getting any bubbles out of any of the fittings. I thought after 10 minutes or so it would show up since it was a smaller leak and the last test showed right away. Nothing. I gave it another 20 minutes and I still see no bubbles. There are a couple of really really small bubbles (Doesn't seem to matter what I do I can't seem to spray on the fitting without it catching some air) but they never get any bigger. Not really sure how else to test this 1 PSI drop. I know temp differentials can make the PSI fluctuate but it's actually hotter today then it was yesterday. I've tapped the pressure gauge at the beginning end when I saw the 1 PSI drop. Is there anything else to account for?

 

[journeyman]

You have to take in affect expansion and contraction in a gas system with air in it due to temps outside I would say ur safe

 

[mdk0420]

You have to take in affect expansion and contraction in a gas system with air in it due to temps outside I would say ur safe

I thought that too, and I'm going to give it another day and see where I end up tomorrow. I just thought it was strange that it lost PSI even though it was scorching hot out today.

On a side note, do you think it's a good idea to paint the pipe inside the house too? I've only had the pipe installed for 2 weeks and it's already developing surface rust. I painted the outside to match the color UGI painted theirs.

 

[journeyman]

What kind of pipe black iron or galvy

 

[mdk0420]

Black Iron

 

[journeyman]

What alot of people dont know is natural gas has marcapin in it so you can smell the gas marcapin can eat through black iron just like ethyal marcapin in propane eats through galvy pipe if you have black iron outside it is illegal any galvy can be outside

 

[mdk0420]

What alot of people dont know is natural gas has marcapin in it so you can smell the gas marcapin can eat through black iron just like ethyal marcapin in propane eats through galvy pipe if you have black iron outside it is illegal any galvy can be outside

Odd, UGI installed the other meter and all the outside fittings from the meter with black iron and then painted them. I figured I'd do the same thing to help it resist corrosion.

 

[journeyman]

No no no black iron outside it will rust and corrode quicker what part of country u in

 

[mdk0420]

No no no black iron outside it will rust and corrode quicker what part of country u in

Pennsylvania. They ran black iron all the way from the street I believe, because everything coming up out of the ground is black iron. I actually asked them about rusting lol. They said they give it a good painting but in a couple of weeks I was going to see rust anyways, and I did lol. It rusts right near all the connections.

 

[journeyman]

Jesus christ if line is in ground it should be pe pipe where it comes out of ground it should be galvy u can run black iron in house but I dont recommend painting it is not gonna slow down corrosion like I've said before good plumbers ain't cheap and cheap plumbers aint good

 

[mdk0420]

All of my houses are like this. All the meters are outside and they all have signs of rust around the fitting connections, definitely black iron.

 

[mdk0420]

I had to look to make sure first about the pipe coming out of the ground. I actually think it might be some form of stainless steel or something. Maybe galvanized, not sure. It goes to its first lockout valve that is black iron and the rest of the feed is all black iron.

 

[journeyman]

Pe pipe will be in ground then it should go to a transition riser coming out of ground then it should be galvy outside and black iron can be run inside

 

[mdk0420]

100% sure its black iron that UGI ran. It has to be legal here though. There is no way the gas company themselves would run an illegal piping... or so you would think lol. That transition riser might be right. It almost cones in? Like a foot long reducer? The supply line from the road actually supplies to two meters that are side by side. the meter on one side is for the other side of the duplex. The riser that I think your talking about goes to a main lock out valve that can lockout both meters, then each meter has an inlet lockout and outlet lockout valve. I believe its either 1 1/2 then goes to 1" line for the separate meters. They did a bunch of elbows and stuff to get around their own piping obstacles that leads to a flange, on the other side of the connection is some sort of black flexible piping that they used for the rest of the run. I actually asked about this flex pipe but I can't buy it without a license. My entrance is pretty straight forward. It's just an elbow over and a service tee in.

Is it illegal nationally or just the standard way of doing things and maybe illegal locally?

 

[CT18]

Yes they use black iron risers and PE underground. We do install black pipe outside and just paint it. It used to be against code in Michigan to use Galv on the gas because of the flaking issue, i think it has since been changed.

 

[Ozzie]

I kept chasing a bunch of tiny leaks in century old gas pipe. I finally took every joint apart and cleaned the threads. Wire brush on male threads and tap on female threads.
Commercial leak detection fluid works far better than soapy water and glycerine in finding tiny leaks
I called Oatey up asking what is the best sealant. They recommended Hercules Megaloc. Contains Kevlar threads. A bit lumpy or gloppy, not smooth flowing. Now no pressure loss after multiple days at 100 psi.

 

[mdk0420]

I kept chasing a bunch of tiny leaks in century old gas pipe. I finally took every joint apart and cleaned the threads. Wire brush on male threads and tap on female threads.
Commercial leak detection fluid works far better than soapy water and glycerine in finding tiny leaks
I called Oatey up asking what is the best sealant. They recommended Hercules Megaloc. Contains Kevlar threads. A bit lumpy or gloppy, not smooth flowing. Now no pressure loss after multiple days at 100 psi.

I used gas rated teflon tape. I tried using some pipe dope I got from home depot but a ton of the joints were leaking during my test so I took them all apart and re did it all with the tape and it made a huge difference. I did end up buying some special 5 pipe dope which I heard it really good stuff but I haven't bothered to use it yet. i was thinking of using it on the unions if they leaked but they haven't. I'm using cal-blue LT to test for leaks. Heard it was a good mixture for testing.

I lost another half PSI so far, been about another 18 hours or so. I'm going to get a higher PSI gauge and throw more air to it to test for leaks again. Might be able to find it then.

 

[chiraldude]

I lost another half PSI so far, been about another 18 hours or so. I'm going to get a higher PSI gauge and throw more air to it to test for leaks again. Might be able to find it then.

Chasing 1/2 psi drop is like chasing a ghost.
You pressurized to 15 psi and lost 3% in 18 hrs. Remember that the meter supplies 1/4 psi (7-8 inches water).
That's 1% of 3% at working pressure which is 0.03% A dog could detect that leak but you will never smell it.
Inspector testing varies but in general, the test is 15 psi or greater and no detectable pressure drop in 15 min. You are done.

If you really want to find the leak(s), pressurize to 100 psi and squirt soap solution on every connection. You will find it but will it be worth the effort?

 

[frodo]

if you lose psi over nite and it is cooler out side, that is ok, but when it heats up the gauge should climb back up

you have a leak.
the obvious places to check first are, valves, check the packing nut, notorious for leaking
valves again, valves leak threw, so you need to disconnect and cap off
if your gas piping is already hooked up to the boiler
STOP...do not pressurize the gas regulator STOP.....
disconnect the piping and cap it off THEN test,

you will destroy the gas regulator if you over pressure you gas line
finding ''seepers'' is a royal pain in the ass, mix a spray bottle with soap/water spray a fitting and stare at it
a seeper will not blow a big bubble but will blow a buch of little bubbles

note*****anywhere you have a valve, the valve must be capped off because valves leak through

 

[Diehard]

like I've said before good plumbers ain't cheap and cheap plumbers aint good

So how does one identify a good plumber, by a high price tag? JK'g