Very faint gas leak (from pipe "t")

riguy

This evening I had to get something from on top of some shelving in the basement, and up on the stepladder my face was right on the gas line, in between two joists. Lucky me, I smelled a very faint but unmistakable mercaptan odor. Damn.

I quickly figured out that the odor is only in the immediate vicinity of a t-junction serving as a 90 degree bend (i.e., a T with one arm capped). It is faint enough that I have to be within 1 inch, maybe 2" of the T to smell anything at all. I brought down soapy water and poured some on, and didn't see any obvious bubbling (I've done this before on LPG grill hose with a small leak, and the bubbles were very obvious) -- and of course it now smells only of Palmolive. I don't think I've ever stuck my head up in that spot before, so have no idea if it's new. For all I know it's been seeping out the whole six months or so we've owned the house.

I have no intention of just ignoring this, or even letting it slide for any length of time. But given that it is a Friday night, I'm trying to decide whether this can wait until Monday morning and be dealt with by a plumber / HVAC guy? Or if we need to go to red alert, leave the house immediately, and call the gas company emergency line. I am inclined to wait -- though I'll email/call our HVAC guy tonight and if he offers a Saturday call I won't turn that down. I'll also do the sniff/bubble tests again now and then and make sure it isn't getting worse.

If that's crazy and we should do the full evac drill right now, let me know, I'll listen.

For what it's worth, this in the room with our gas furnance and water heater. Black iron pipe that is not new, but I wouldn't know 20 year old from 50 year old.

BobC

I'm only a homeowner but I'd be nervous about that unless I KNEW where the leak was. You were up high so the leak could be lower down, put some solution on any joints you can find.

A friend discovered a leak in his furnace room sometime back and the gas company verified it was after the gas shutoff so the locked it off. His plumber replaced a short length of pipe and a couple of elbows and all was well after rubbing some money on it.

Bob

jonny88

turn of all gas appliances and check gas meter.If you see it spin you might have a leak,not the best test I know but can work.I would call a plumber before utility company as they will lock your meter.Fantastic works pretty good and shows bubbles.I would get your plumber asap to address situation .

EBEBRATT-Ed

No one knows how big the leak is, it's probably small but do not become a statistic.

I would shut the gas off at the meter and get someone in there tomorrow.

riguy

Thanks. Email in to my HVAC guy.

I did 'sniff' and use soapy water at all the junctions I can get to, and the only place with even a trace of odor is within an inch or two of that same "t"; no visible bubbling anywhere.

I did not shut off the water heater pilot -- the only gas being consumed right now -- but for what it's worth with the pilot running, my meter is showing about 0.01 cu ft/min of flow.

bmwpowere36m3

Did you put soapy water on the tee itself and not just the joints… I've heard of porous castings or maybe a hairline crack.

I just plumbed some black iron in my house for gas. When I first pressurized the system, with about 15 psi, I could see the pressure dropping immediately and hear a slight hiss. Leak was obvious and I fixed it.

Re-pressurized the system and it seemed to hold. It was late, so I just left it at 15 psi. Next day, about 10 hrs later, the pressure had dropped 3 psi. I started soaping joints and found 1 with a very slight leak. So again, fixed it.

Now its been holding 15 psi for 5 days… +/- 0.5 psi due to temp.

I didn't test for leaks at 0.5 psi (NG service pressure after regulator) or close to it (Code min is 3 psi). So I don't know how well a very, very small leak might show up with soapy water.

SWEI

bmwpowere36m3 said:

I didn't test for leaks at 0.5 psi (NG service pressure after regulator) or close to it (Code min is 3 psi). So I don't know how well a very, very small leak might show up with soapy water.

Higher pressures find more leaks faster. If it holds for days at 30+ times operating pressure you can rest easily.

bmwpowere36m3

@ SWEI

Yeah, I'm not concerned about my installation... actually went up to 30 psi while testing with suds and have it set at 15 psi now for days.

I was just thinking when testing for leaks in an existing system, with gas on, only seeing about 0.5 psi and testing for leaks...

j a_2

I am a plumber and I can understand your fear of calling one in, It is costly, and sometimes you don’t get the cream of the crop…However that said, you truly do need to call the gas co., or plumber and find the source of the leak ASAP….It may be just a tiny what we call a fizz leak or it could be a sign of a potential serious issue…..Its your house and your call, you must be concerned other wise you would not have assked for friendly advise here on the wall…..Good Luck

j a_2

null
That's how its done in Mass..I have always felt very comfortable with it....Realizing thou some states may different... Here we see lots of old hubless fittings, dirty gas, old houses with live gas lines going to the old gas lanterns..And of course mr. Handy Dandy's beautiful artwork...As soon as I saw handy dandys work I was out of there in a Flash....

ChrisJ

j a said:

null

That's how its done in Mass..I have always felt very comfortable with it....Realizing thou some states may different... Here we see lots of old hubless fittings, dirty gas, old houses with live gas lines going to the old gas lanterns..And of course mr. Handy Dandy's beautiful artwork...As soon as I saw handy dandys work I was out of there in a Flash....

They actually allow natural gas appliances in Mass? With all of the coddling they do I'm surprised.


To the OP, I'd want that fixed as well. Many times at friends houses and even where I work I catch whiffs of that smell when near appliances and have always wondered why. For a long time I thought it was normal, maybe something seeping through the pipes, I don't know.

But with all of my new gas piping that I installed in 2011 I have never even once smelled anything.

riguy

ja: Thanks. I'm not worried about calling in a plumber, like I said, there is no way I would leave this as-is; it will get fixed. I fully intend to have someone in promptly, like Monday.

My only question was whether to live with it for a day or two 'til plumber makes a visit. Or to call gas co emergency line for an instant response, which would probably mean a meter lockout and no heat / hot water for the weekend. As of this morning I still can't find any gas odor except with nose right up on that on joint, so my layman's inclination would be to leave the gas on 'til plumber gets here, but thought it ask the pros if that sounds unwise.

j a said:

I am a plumber and I can understand your fear of calling one in, It is costly, and sometimes you don’t get the cream of the crop…However that said, you truly do need to call the gas co., or plumber and find the source of the leak ASAP….It may be just a tiny what we call a fizz leak or it could be a sign of a potential serious issue…..Its your house and your call, you must be concerned other wise you would not have assked for friendly advise here on the wall…..Good Luck

ChrisJ

The problem is, no one can possibly tell via keyboard how bad it is. I also don't think anyone would ever want that responsibility.

Imagine if someone told you "It's probably fine, I'd leave it until Monday" and then somehow, something really went wrong and you lost your house and possibly family.

How would that person feel?

Even if it is slow, what if it is a small hair line crack that after people walking across the floor a few times and flexing the pipe causes it to open up?

Tim McElwain

Simple answer when you smell gas immediately call the gas company or propane company. Better to get a little cold than the alternative. This is from someone who worked for a gas company for 28 years. Sometime the gas company will put some ivory soap (we called it soaping a leak) on a small fuzz leak on low pressure less than 1/2 a pound (14" W.C.) and give you some time to have it repaired. In other cases the source can be isolated by shutting off a valve. It is not always typical that they just come out and shut off the meter and leave. If they do that I would call the local fire department and report them.

jonny88

With all due respect Tim I have found gas company are to quick to lock meter.Here is one for you,A customer smelt gas and called gas company.They came with their gas detctors and necessary tools but I promise you could not find leak so naturally they locked meter.Winter in NY,not pleasant.Customer called me to check it out.Bear in mind meter is locked but I could still smell gas.I got some Fantastic of customer and sprayed collars on meter (gas valve going to meter is still locked).Lo and behold what do we see but bubbles coming from collar on meter.Obviously gas valve did not shut all the way.Tightened meter and did a pressure test which held.Gas company came back and opened meter.To the OP I have had pinholes in fittings straight from supply house and not Chinese fittings I may add.Why dont you do a meter test or for the life of me and no offense intended you know you have a gas leak why wait till Monday.Dont take chances we dont need more headlines.

j a_2

null
Agree, and sometimes it takes 3 calls to get one self proclaimed tech that has a half a clue as to what they are doing...Then they have to go back to the truck for 30 plus min to call some far away phone boss,as to what he should do next? And he says sit in your truck get nice and warm and read the news paper.....I'll look up the procedure for a gas leak....

EBEBRATT-Ed

I met the gas co at a house to relight house and the customer had a problem with the boiler, gas had been shut off at meter and locked.

Gas man took unions off meter and they had a blank disks installed in the unions.

He explained that there SO valves leak and they had recently blown up a house where they had shut gas off and enough gas had leaked through meter into house out through a disconnected appliance and caused an explosion. Hence the disks.

ChrisJ

EBEBRATT-Ed said:

I met the gas co at a house to relight house and the customer had a problem with the boiler, gas had been shut off at meter and locked.

Gas man took unions off meter and they had a blank disks installed in the unions.

He explained that there SO valves leak and they had recently blown up a house where they had shut gas off and enough gas had leaked through meter into house out through a disconnected appliance and caused an explosion. Hence the disks.

But, what if the discs leak?

j a_2

Here is a pic of a couple of disc's . near impossible, for them to leak. But what is possible they be installed wrong. Nothing surprises me anymore

RobG

I have found that they use the discs for the HO or renter that chooses to cut the lock and they won't know enough to drop the meter and remove them.

j a_2

They have there place.....I have a bin full different sizes...never had a need to use one..

riguy

Thanks for the assistance. Plumber was here this morning and determined that there was a small leak, barely enough to bubble, from a spot on the thread of the cap in the unused end of the 't'. Now fixed.