Best way to detect a leaking gas line?

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chiraldude said:
Not so much the price but the demand. If you find someone who is booked up for 2 months, odds are he is the guy you want. A mediocre plumber may be busy but will always have time to squeeze one more job in.
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Yeah that makes sense!
Find it in all the trades.
 
frodo said:
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
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I'll try it disconnected from the meter (There's a shutoff valve before and after the meter they are both turned off). My shutfoff valve before the boiler isn't leaking (I smothered it in the cal-blue stuff). It is capped off after the valve as well right before the boiler. I tested all of the fitting connections at 100 PSI and applied it with my finger so it went on very smooth and bubble free and not a single bubble on any fitting. I checked for porous fittings as well by slathering on some leak detector and nothing. At 100 PSI I lose around 5 PSI an hour so it is quite a substantial leak. Like I said I'll disconnect it from the meter and see if maybe it is leaking back through the valve on the meter. My final test would be to slather the leak detector all over all the piping and see if maybe there is a porous pipe somewhere... Baffled at how much it is leaking and yet I can't find it.
 
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Shouldn't matter where I have the gauge. Rather just keep it on the tee I have setup inside. But I will be disconnecting it tomorrow. I bought the caps I need today but it got pretty late out and has been raining. Once I get it isolated I will put 100 PSI to it and see what happens. I'll report back in on sunday if I'm still having problems with it. If that meter valve isn't the issue I'm probably just going to do what chiraldude said. Screw it... If it is leaking that slow and not through any of the fittings after my tests then it can't be that big of a problem. It'll definitely pass the inspection test but I'm frustrated that it keeps losing air somewhere.
 
Are you using a kuhlman guage. If you are around here it has to be tested at 14" water column for 3 minutes on existing inside gas
lines which would include your line to the boiler. You can't have any droppage or the gas company will turn it down. They will
do like Frodo said and take the meter off and test it through the house side of the meter setting. I think putting 100 lbs on that
gas line could start some problems.
 
TomFOhio said:
Are you using a kuhlman guage. If you are around here it has to be tested at 14" water column for 3 minutes on existing inside gas
lines which would include your line to the boiler. You can't have any droppage or the gas company will turn it down. They will
do like Frodo said and take the meter off and test it through the house side of the meter setting. I think putting 100 lbs on that
gas line could start some problems.
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Not sure I know what you mean by the water column. I'm using a home depot gauge. My inspectors requirements were that it has 1/10th increments but it meets that requirement. It get's tested for around 15 minutes or about the time of visually inspecting things. It doesn't drop fast enough for them to detect it in that time (It only drops around a 1 PSI after 24 hours) and they also only test it at 10 PSI, I've been putting it to 15 PSI. A half PSI over the course of the day is not enough to detect any leaks with any soapy solutions I noticed, so I had to put the pressure up to detect it, however I am not finding anything even after that much. I even found that applying it with my finger instead of spraying it actually puts it on much smoother and is about 99% bubble free afterwards, and there were no bubbles on any of the fittings or even around the fittings since I tested for porous fittings as well.

My only hope is that frodo is right, that the gas valve is leaking back into the meter. That would be an irrelevant leak since it would be open anyways during normal operation. I just pulled the meter off and applied another 100 PSI to see what I have going on. The last thing I can think of doing is coating the entire piping to see if there is a pin hole somewhere in the pipe I bought. It is all new piping inside the house, but it currently will only be used by the boiler (Maybe the stove and a wall heater in the future). I'll check it in a couple of hours to see where the PSI is at.
 
mdk0420 said:
I'm probably just going to do what chiraldude said. Screw it... If it is leaking that slow and not through any of the fittings after my tests then it can't be that big of a problem. .
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see, we are talking about gas here, and when gas leaks, it is not the same weight as air, so it tends to pool up in one spot.
the cloud of gas gets bigger and bigger as time goes on.
then you come stumbling in the house after it has been locked up all day, turn on a light switch and
explosion on main street, fire and rescue are at the scene, news at 10
 
I agree which is why I would rather have it not leak but it's not leaking through the fittings. I've tested each fitting half a dozen times. Several times under 100 psi. And the last time with as smooth of an application as I could most fittings had no bubbles at all, the others had maybe 1 or 2 tiny specs that we're from applying it. The only two things that could be leaking now is the valve that led to the meter or the sections of piping I used that may have some porous holes.
 
This is much more promising. Already been a couple of hours and I haven't lost any air at 100 PSI. Yesterday I lost about 5 PSI in less then an hour. I'll keep it going for 24 hours and if all is well then I'll call it good. Thanks!
 
frodo said:
Cool, gas is dangerous
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Thanks a lot frodo. Never thought the gas valve would leak like so, guess it just isn't made to handle high pressure though. Been about 14 hours and the pressure is stable. I'm at the home stretch for this boiler project now. I'm going to buy the PVC piping tomorrow and finish running that tomorrow and finish pressure testing my water lines. Should be able to get the inspection out here this week. I need to call him on whether he needs the boiler to be functioning or not though. UGI said they test the gas supply through the unit that uses it (Only the boiler atm). So the meter is locked out. But if my inspection needs the boiler to run then I can't without UGI unlocking it lol.
 
frodo said:
see, we are talking about gas here, and when gas leaks, it is not the same weight as air, so it tends to pool up in one spot.
the cloud of gas gets bigger and bigger as time goes on.
then you come stumbling in the house after it has been locked up all day, turn on a light switch and
explosion on main street, fire and rescue are at the scene, news at 10
Click to expand...

First off, only propane has the "pooling" problem because it is more dense than air so in the absence of air flow, it will sink and collect in low spots. Natural gas is mostly methane which is less dense than air so it will tend to drift up and work its way up and out of your house. Now, in this case, we are talking about a tiny leak that, at 1/4 psi, will amount to something like a pint (gallon at most) of gas leaking out over the course of a week.
Think about how long you would have to leave a gas burner on (full open) before the house would explode. You would need at least 10 cubic feet to leak out before the concentration got to the point where it would ignite.
If a tiny leak were dangerous the inspector would require zero pressure drop in 24 hours but they only watch for 15 minutes because tiny leaks are not dangerous.
 
Your state tests gas lines a whole lot different than they do in Ohio. Columbia Gas has a not drop what so ever on the guage. I could never have left
a house knowing that there was any kind of leak. I guess the only difference here is it is your house. It sounds like you know a lot about gas so
you know what you are doing.
 
Not different from what I stated before.
Code calls for test pressure of 1.5 times working pressure (min of 3 psi) and minimum of 10 minutes observation time. Anything over 5 psi and 15 minutes is overkill according to code.
How it has been for me is that I pump up the pipe to 30psi, inspector arrives and marks the location of the gage needle with a sharpie, looks at his watch and writes down the time. Inspector does a walkthrough of the installation and comes back to the gage. If the time is greater than 10 min and the needle hasn't moved, you pass.
Also required to have a valve on the system so he could crack it open and verify the gage needle actually dropped and was not stuck.
Maybe Ohio goes by some other code standard?

https://codes.iccsafe.org/public/document/IRC2012/chapter-24-fuel-gas
 
Yeah I found out that my inspector only does a 10 minute test at 5 psi. I have left it for several days now at 100 PSI and the only fluctuation has been due to temps. It has been pretty much steady between 98 and 100 PSI since my pressurized it. I think I'm going to try and blow air through it too so I can try to clear the pipe of any debris before putting it into service.
 
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