Gas line test fail, help!

gliptitude

I'm a homeowner and DIYer with a hot water heating system that I finally brought back to life last winter, (thanks in large part to folks in this forum community). I did some major work here, replacing broken pipes and fittings, replacing circulator pump, REBUILDING CRACKED RADIATORS.. But now I am having a very unexpected problem that seems like it should be a cinch but is now baffling me.

I'm trying to get the utility company to turn my gas service on so I can fire up my boiler and heat the house. They apparently have new standards and test procedures which I am failing. I had the service turned off last spring to save money, (the boiler is the only gas appliance in the house and the utility company charges a monthly fee for gas, roughly equivalent to my entire monthly electric bill in the summer).

It is the same gas line I used and passed with them last year.

After failing once I did some work to simplify the system and I tested for leaks. I eliminated all of the unused lines in the house and I re-did a remaining joint that showed a tiny leake. Existing lines are black iron threaded pipe.

After these repairs I STILL failed the utility company's test. He even went around and did his own leake detector test on EVERY remaining joint. He found no leake but he said I am losing pressure beyond what is allowable and he declined to turn the gas on.

I have made arrangements and preparations to replace almost everything with CSST but I haven't pulled the trigger yet because I am not convinced that there isn't something screwy going on here, and that I will be scrapping the entire line for no reason and potentially still not pass.

.. I am presently doing my own pressure test, according to some videos I watched and using a brass are valve that I just bought.

.. I PUMPED TO 10 PSI AND HAVE HELD 10 PSI FOR FOR NOW 30 MINUTES.

Does this not confirm that I am complying with conventional standards? 10 psi is much MUCH higher than the gas service pressure.

I have another appointment tomorrow afternoon to turn the gas on. Still enough time to switch in the CSST I think. But it will involve cutting the old line and it is basically an irreversible change. I don't want to abandon the existing if it isn't actually going to help.

What is going on here?

Steamhead

I would not recommend going to CSST. There have been cases where a nearby lightning strike has blown holes in it and ignited the escaping gas. Supposedly the latest versions are more durable but they said the original versions were "fine" too. Caveat Emptor.

Try pressurizing to 30 PSI or so and see what happens. How much pressure does the gas company use for their test?

gliptitude

Lightning strike is the best known hazard of CSST but it is supposed to be easily prevented with a proper installation. The gas line must be GROUNDED. I've got the ground bond fitting in hand and a length of 6 copper wire.

If I correctly understand what the gas company does to test, (he did try to explain it to me) he simply pressurizes the line with the gas supply itself - something like 9.6 inches water column. Then he turns it off and monitors the pressure with his gauge. Mine went down to 8.8 within 5 minutes. I think he said maximum drop is .2 in 10 minutes.

9.6 Inches water column converts to less than 1 pound square inch.

.. My previous leake detection test just used the gas supply itself for pressure. Now that I have much higher pressure (with pumped in air) a couple more leakes are showing. Fixing them will entail quite a bit of disassembly so I may still go with the CSST.

I think 30 psi is way too high for testing, not necessary and possibly damaging, especially for the CSST.

BBros

Are any of the tests including a regulator? System or appliance... I had a vent failure on one that wasn't detectable. Changed the regulator and all was well.

Steamhead

In Baltimore, 30 PSI for 24 hours with zero pressure loss is the required test. The city will not pass the job without this test. After they approve the job, the gas gets hooked up.

JUGHNE

Remember, that when you pressurize air it gets warm. You put that air into a cold pipe in will cool and contract. If the test is to be at 30 PSI, I put in 40 and watch the gauge. It may drop and then stabilize. It will depend upon the temp of air going and the temp of the pipe ambient. Surely you would think the NG employee knows about this........but then again.

For leak detection I might go to 50 PSI. Just be sure gas valves are not connected to that pressure.
I usually open the union to be sure that high pressure does not hit the main gas valve.
I too would avoid the CSST stuff. It is so thin that it will surprise you when you cut it.
I have handed a 6" length of CSST and a 6" black nipple to a customer and asked if they can feel the difference in weight, they chose the black piping.

gliptitude

Well in the minutes since my initial post 10 psi air is revealing leakes that gas pressure had not. So it is a bit more clear now. .. Still the pressure loss seams within bounds, but a leake is a leake I guess.

I may be in for an all-nighter, breaking down and retightening/resealing the whole thing.

Steamhead, I will consider increasing pressure.

JUGHNE

The gas company is relying upon their regulator to hold that pressure. As BBros that regulator could be leaking. Do they shut the gas off before their regulator and meter?

I have found very small leaks in meters themselves.

Zman

The gas shutoff valves themselves are often the cause of the leak under high pressure, you may want to focus your efforts troubleshooting efforts there.
I would never consider converting to CSST. The industry has managed to convince everyone that the only problem with their product is remedied but a simple ground wire. There are many failures that are unrelated.

adambnyc

I went thru almost the same thing. When I self installed my tankless hot water heater, I needed to upgrade all the gas lines in my house. I started out with Home Depot CSST myself. I decided to get rid of it and invested in a ridgid R12 + dies so I could thread all my own black pipe.

I was also failing pressure test. Put on your pressure test gauge. Shut off all valves to your appliances. Also make sure you have a full port shut off right after the meter. You shouldn't pressure test by putting pressure backwards into the gas meter. Close all the shut offs. Pump up to 30 PSI. Use leak detector or a bottle of water+dish soap. Spray all your joints and look for bubbles. You will find your leaks for sure.

Some guys don't like to use gas tape, I've found gas tape + pipe dope works great for those joints you just can't get to seal right. Just make sure you are two threads from the edge before using it.

hvacfreak2

On problem jobs we would disconnect the piping from the appliances and install caps , or remove the connecting piping and soap the opening to look for a valve that was bleeding through. 30 psi was the standard then , now in most places it is 10 psi with a gauge with 1/10 graduations or something like that.

adambnyc

In NJ, my plumbing inspector wants to see the line hold 15 PSI for an hour.

adambnyc

I will say one thing good about that CSST. I did a basement dig out/ renovation last year... still renovating... but we dug down 4 feet. The CSST was a god send when we had to move the gas dryer and hot water heater around almost daily. Really amazing for a temporary solution but I got rid of it when the appliances landed on their forever home.

EBEBRATT-Ed

Tinfoil wrapped in a plastic jacket. JUNK AS FAR AS I AM CONCERNED

Mark Eatherton

Watched a 3 million dollar home burn to the basement foundation when lightning hit .6 miles away and it was fully grounded. BELIEVE WHAT YOU WANT. IT HAS COME VERY CLOSE TO BEING RECALLED AND BANNED IN THE PAST.

BobC

NOTHING can replace steel pipe gas line safely.

Bob

gliptitude

adambnyc said:

I was also failing pressure test. Put on your pressure test gauge. Shut off all valves to your appliances. Also make sure you have a full port shut off right after the meter. You shouldn't pressure test by putting pressure backwards into the gas meter. Close all the shut offs. Pump up to 30 PSI. Use leak detector or a bottle of water+dish soap. Spray all your joints and look for bubbles. You will find your leaks for sure.



Some guys don't like to use gas tape, I've found gas tape + pipe dope works great for those joints you just can't get to seal right. Just make sure you are two threads from the edge before using it.

I haven't got a shutoff to isolate the meter from the rest of the line and I'm not going to be able to get one before my appointment tomorrow. Will 30psi without "full port shut off right after the meter" damage the meter? Or compromise the test?

.. At any rate, like i said in my last post, 10 psi revealed a few new leakes. And I feel like i've got my work cut out for me now.

.. I've started using black dope, which my uncle recommended and lent to me.

BobC

YES IT WILL

Bob

rick in Alaska

We are only required to hold ten pounds for 30 minutes here. But, when I do test on an existing line, I will take all the supply lines off the appliances before testing. Even a ball valve can leak by, and I don't want to take the chance of having 10 pounds on an appliance regulator as you can damage them very easily.
I have pressurized gas lines with propane and used my gas leak detector to find leaks. I have had very bad results testing with soap bubbles.
Rick

Zman

You cannot pressurize the meter without damage.
What's the big deal with isolating it? Meter has a union, usually a valve and 2 nipples is all it takes.

adambnyc

Reschedule the appointment with the inspector. If the inspector himself didn't tell you that you needed to do that, you've got a hard case on your hands. Might be why he's automatically failing you. If you backfeed the meter with pressure during the test and damage it, guess who's gotta pay for a new meter.

Also, if 10 PSI is showing leaks, I really gotta question the safety here. We gotta remind ourselves sometimes, the inspector is there to make sure we stay safe. I'd rather have an inspector fail me and I completely redo my work than put my family in a dangerous situation. There is no reason at all why a properly put together gas piping system can't hold 30 PSI stable for hours. If your leaking at 10, that's a problem. 10 PSI stable in my experience has been pretty easy to hit.

Pipe dope plus that Home Depot yellow tape will probably give you a lot of success. You should also be using two pipe wrenches on all joints and tork down to the appropriate tightness. If your using a pair of channel locks or something, your not using the right tools.

Steamhead

In Baltimore, we are not allowed to use tape on gas pipe joints........

adambnyc

rick in Alaska said:

We are only required to hold ten pounds for 30 minutes here. But, when I do test on an existing line, I will take all the supply lines off the appliances before testing. Even a ball valve can leak by, and I don't want to take the chance of having 10 pounds on an appliance regulator as you can damage them very easily.
I have pressurized gas lines with propane and used my gas leak detector to find leaks. I have had very bad results testing with soap bubbles.
Rick

Interesting you say that Rick. I've only had the most success using liquid leak detector and not the "sniffer". I guess it also depends which sniffer your using.

I suppose my main issue is that I look for leaks using the system pressurized with air not gas. If I'm looking for leaks because I smell gas, I tend to freak out and shut the gas.

gliptitude

.. I'm moving forward with this. Breakdown went smoothly. The first joint reinstalled smoothly. But now I am having a terrible terrible time with a coupler between two long lengths.

I suppose i am just not lined up straight enough to catch threads. It sure looks straight though.

I first installed the coupler in order and then the next pipe. After i couldn't get that together I removed the coupler and instead threaded it on the next pipe, then tried to connect that whole assembly to the first pipe. Not working and i've spent over an hour trying.

There are hangers holding the pipes to the floor joists. I ended up installing some straps of my own and cutting the old hangers, thinking this might help.

.. Is there a trick to lining up and screwing together long lengths of pipe?

It's 1 1/4" pipe, so not easily manipulated in the space.

adambnyc

Nothing beyond lining up the pipe properly. When threading any connection, I usually spin the pipe in the opposite direction against the threads in the hub until I feel the pipe click/seat itself ensuring I'm lined up properly and don't risk a cross thread.

Being that you were able to move the coupler between pipes, it sounds like the threads are fine. It just sounds like your having trouble lining up. Adjust the hangers

1 1/4 gas pipe. Pretty big. I've got gas pipe that size in my house for the tankless.

Zman

I agree that your problem is likely alignment.
Many contractors past and present use the thread protectors that come on the pipe as couplers. If you are having trouble with leaks at couplers, you may want to replace them with a quality coupler.

gliptitude

I eventually got everything put together. I re-pressurized to check for leakes, but only to 5 psi this time, to hopefully avoid damaging meter. Maybe not enough to gauge but we'll see how it goes.

.. This gas company safety check might fit the familiar definition of "inspection" but it is not called that and there is no punitive consequence for failure. They will just decline to turn the gas on.

Hopefully I didn't damage anything.

If I fail this time I'll probably consider hiring somebody.

ratio

Keep in mind that many appliance gas valves are stamped max 14 in wc and the lawyers will tell you that you own the liability if they are exposed to more than that. I don't recall reading if they were removed from the gas line prior to your 30# test or not.

gliptitude

Well .. I'VE GOT GAS!!!!! Leak free and zero detectable pressure loss. I stuck with the old black pipe and am very happy with that decision.

- BUT -

The pilot won't light.

I told the service guy everything I had done and that I found out afterwords that I had risked damaging the meter and the boiler valve/regulator. He said the meter was probably okay and that the boiler part may or may not have survived.

It is an automatic ignition pilot. We let it spark for five minutes or so before I shut it off.

He showed me the tiny tube that gas flows through to the pilot and he suggested that that may have been clogged with debris under the higher air pressure, and may possibly be fairly easy to clear with the right tool.

.. Regarding the original leak(s) that caused me to fail the first two times around, this guy agreed with me that they probably did exist (undetected) last year, that they were very small leaks according to the measurements and that that generally is not a life or death situation in a house as old and drafty as mine.

On the bright side, I never would have even known to abate the hazard had I not turned my gas off last spring because they would not have had the occassion to do their new required start service test if I had had it on continuously.

bob_46

Did you purge the air out of the line?

EBEBRATT-Ed

People don't realize (shouldn't say that a lot of people do) because we work on gas day in and day out and electricity day in and day out and I am a licensed gas fitter and a licensed electrician that the stuff is dangerous.

We work on it so much that we start to take the danger for granted, I probably have done it myself more times than I would like to admit.

To the homeowners and do it yourselfers who read this: BE CAREFUL. I am not telling anyone what to do but if your not sure call in a professional

delta T

So wait, did you put 30 psi to the appliance valves or not? I'm still not clear. If you did, they are most likely toast. If not, then you may need to purge the air out of the lines, depending on the length of run, this may take some time. If you are uncomfortable doing this, call a pro. as Ed said above....BE CAREFUL!!!!

rickh

Does anyone else have a concern with giving recommendations to a homeowner when it involves a gas appliance? There is a big difference working with other piping around the boiler and REBUILDING RADIATIORS as he was so proud to shout out. A water leak doesn't blow up. A gas leak is a leak no matter what, if you need to ask such mundane questions you should be calling someone to do the work for you. At least learn how to spell leak.

Henry

In Canada we don't allow non licensed gas fitters to play with gas. Too many DYI have had accidents. The big box stores have stopped selling gas appliances to DYI as it is a liability issue. Please read NFPA54 or B149.1 for gas test requirements. You must isolate meter and equipment to test. Several years ago, we had two failures of CSST and also my own install. I discovered welding splatter that pierced the S/S under the plastic coating. The leaks were NOT at the joints and we had to use the electronic sniffer to find the leak in the jacket. I did a water test and it leaked. Meanwhile the manufacturer sent a whole report on the piece from my house with so called pictures. It stated that there was no leaks. One cannot believe the largest manufacturer of CSST! COVERUP! We switched supplier.

gliptitude

delta T said:

So wait, did you put 30 psi to the appliance valves or not? I'm still not clear. If you did, they are most likely toast. If not, then you may need to purge the air out of the lines, depending on the length of run, this may take some time. If you are uncomfortable doing this, call a pro. as Ed said above....BE CAREFUL!!!!

No I did not put 30 psi into ANYTHING. 10 psi was my maximum.

rickh said:

Does anyone else have a concern with giving recommendations to a homeowner when it involves a gas appliance? There is a big difference working with other piping around the boiler and REBUILDING RADIATIORS as he was so proud to shout out. A water leak doesn't blow up. A gas leak is a leak no matter what, if you need to ask such mundane questions you should be calling someone to do the work for you. At least learn how to spell leak.

Mundane? I'm not trying to entertain you. I have asked basic and fundamental questions. I had not been concerned with whether you found this to be interesting or not.

This is not my first experience working on gas lines and it is not something I originally endeavored on my own or without professional assistance.

Hot water of course is a less hazardous substance than natural gas. I mentioned my experience in the first post as a frame of reference and a means of identifying myself.

In the last 24 hours I have sucessfully repaired my gas lines, to the standards and satisfaction of my local utility. This was substantially less work and it entailed substantially less research and experimentation than the water work I did last year.

I can understand a professional having reservations talking about natural gas with non-professionals. That's your prerogative and not any of my business. .. I felt inclined to ask my questions here because I had had a very productive and robust experience here in the past. Really I was pretty shocked back then by how much knowledge and encouragement was freely offered to me here.

EBEBRATT-Ed

@gliptitude People on this forum are here to help but we have no way of knowing the experience , knowledge or lack there of of any poster. Some people do crazy things.

My favorite was the NY apartment where they shut off the gas so someone tapped into the drip leg of a gas fired water heater in the next basement over that had gas service WITH A GARDEN HOSE and ran it through the basement to his furnace.

I am glad you fixed your leaks and got the gas turned on.

Be advised to do a gas pressure test you are supposed to disconnect and cap every gas appliance and the supply pipe coming in from the meter should be capped, regulators removed. Low pressure gas in MA. is tested at 3 psi with a low pressure or mercury gage. It may be different in your area.

no cast iron or galvanized fittings can be used.

You may have worked on gas piping but the questions you asked show that you haven't been involved with gas testing.

Mistakes and accidents happen to anyone. Even those of us that are experienced.

A couple of years ago a plumber in the Worcester area was purging a propane line to a gas boiler. I herd there was a leak in his purge line and the water heater pilot light the thing off.

The house was blown 1 foot off the foundation. He didn't make it. This fellow had been a plumbing inspector in one of the towns.
40 years experience.

Gas and electricity don't care who you are or how much experience you have.

Don't want anyone getting hurt