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tonocats 04-11-2006 12:13 PM

Gas line pressure test
We are trying to get several unfinished items signed off for inspection in order to sell our house. When our addition was done we relocated the water heater which required an extension of the gas line. We have attempted to pressure test the gas line but it won't hold pressure. Initially we replaced the gas shut off valve on the water heater as well as the clothes dryer. The only remaining outlet would be the floor furnace. We went under the house and checked all accessible joints, tees & unions including the point at the floor furnace, with a soapy solution. No leaks were evident yet we still cannot get the line to hold pressure. Any suggestions on where we go next? We are presently in the process of completely removing each valve and capping the lines off but are not able to do this with the floor furnace. Any advice would be greatly appreciated.

CraigFL 04-12-2006 06:37 AM

Won't your gas company help you with one of their "sniffers"?

cabinetsetc 04-14-2006 06:29 PM

Question: When testing, did you shut off the main valve? If not,you are simply sending the gas back through the line. Gas feeds don't have much pressure.

woodworkingmenace 04-28-2006 01:29 PM

Actually, the Gas Company should be the one testing... Putting a meter on the line and pumping air into it, for 15 minutes. I think its 60-90 psi for 15 minutes, even though they only pump ounces through the lines...(go figure:)).

Its probably a valve that is not holding. Or, you left your pilots on, stove, furnace, or hot water heater? Many variables...

And yes, the Gas Company would have shut the meter off, in order to test this, they are fanatical about testing this sort of thing, in most places...


Plumb1up 05-04-2006 08:57 PM

Actually the gas company's responsibility stops at the meter. They will check out appliances and related connectors to the piping, if asked, but they won't be crawling the house to find leaks, that will have to be done by you or your local plumber.
Are all ends of pipe runs capped off (best test)? Or are they just valved and turned off at the appliances?
Valves are notorious for leaking through the valve themselves and through the valve stems. Be sure you soap the valve stems. If the system is still connected after the valve then you really have no way of checking to see if the valve is holding.
You don't need 60lbs in the system. The code accepted test, for a non welded system, is 15lbs for 15 minutes. And you don't want that pressure going to an appliance, especially if it has a regulator. You will blow the diaphram in the regulators with excess pressure. Gas systems are designed for and only supplied with 1/2 pound psi gas.
Good Luck

woodworkingmenace 05-05-2006 12:06 PM

Well then, my Gas Company are really on the ball, as this is what they used for my lines.

They took extra precautions in which I am grateful to them. (Them knowing I was a City Employee may have helped, as we service them also:))...

Yes, I was amazed they put that much pressure through the lines, as a test, then told me they only put "ounces" through as a regular pressure. I asked them why they used to much, and they said they wanted to be sure!

I go by my own experiences on here an elsewhere, what I have done, what I have experienced and all the mistakes that I make so that others dont have to make them... (Sure wish I had something like this, when " I " was starting out! Then I would have saved thousands in mistakes!)...

Just my two cents for what its worth, and a wee bit extra for the collection plate


St. Anthony 09-30-2006 02:08 PM

I have an extensive leak detection background. Can you tell me how you are pressuring the line (compressed air or an inert gas) & what type of pressure gauge you are using? Is the line completely visible at all points or is it partially hidden at any point? I will do my best to help you solve your problem. However, as someone has suggested, the gas company and or a licensed plumber are your best bet. If you have a problem & you did the work & testing (assuming you are not qualified to do this sort of work) there are liability issues. Pete

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