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    jamlove's Avatar
    jamlove Posts: 78, Reputation: 2
    Junior Member
     
    #1

    Aug 3, 2005, 04:18 PM
    How to pressure-test gas pipe
    Hi again!

    First, MANY thanks to you experts for the help I've gotten in the last month. I passed my plumbing inspection for my new bathroom and kitchen!

    Now, on to one more little one. I'm installing gas lines. The house was previously on oil heat and all other appliances were electric, so this is completely from scratch.

    As is probably true in many places, our local codes say that the system must be "under test" when the inspector comes. It says to fill the pipes with 10psi of air, and that it must maintain the pressure for at least 15 minutes.

    My question is, HOW? Is there some kind of device I've never seen that screws onto the end of a black iron pipe, but has a bicycle-pump connection for pumping air in?

    Any help is greatly appreciated. I've been searching Google but so far haven't had much luck.

    - james
    speedball1's Avatar
    speedball1 Posts: 29,301, Reputation: 1939
    Eternal Plumber
     
    #2

    Aug 4, 2005, 05:43 AM
    Snifter valve needed here!
    Quote Originally Posted by jamlove
    Hi again!

    First, MANY thanks to you experts for the help I've gotten in the last month. I passed my plumbing inspection for my new bathroom and kitchen!!

    Now, on to one more little one. I'm installing gas lines. The house was previously on oil heat and all other appliances were electric, so this is completely from scratch.

    As is probably true in many places, our local codes say that the system must be "under test" when the inspector comes. It says to fill the pipes with 10psi of air, and that it must maintain the pressure for at least 15 minutes.

    My question is, HOW? Is there some kind of device I've never seen that screws onto the end of a black iron pipe, but has a bicycle-pump connection for pumping air in?

    Any help is greatly appreciated. I've been searching Google but so far haven't had much luck.

    - james

    Hey James, Welcome back!

    Yes there's a device you can make yourself. You failed to mention the pipe size so I'm going to assume it's 3/4". You take a 3/4"(or your pipe size) coupling and bush it down to accept a snifter valve. A snifter valve looks like the air valve on your tire except it has threads at the base. Snifter valves can be picked up at some hardware stores and most auto parts stores. Since most air compressures the plug into a cars cigarette lighter have a gauge I would pump up the gas line with that or a bicycle pump with a gage.
    OK! Ya got 10 pounds of air in the gas line what now? We check for leaks by taking a mixture of water and dish detergent and painting each joint with it. If you see bubbles then you have a leak. No bubbles and you're home free. Good luck, Tom
    jamlove's Avatar
    jamlove Posts: 78, Reputation: 2
    Junior Member
     
    #3

    Aug 4, 2005, 06:48 AM
    Aha!
    Great! I get it now. I'll go shopping for bushings later today! Probably will need a combo of several, unless I get lucky and make it to the specialty hardware store before they close this afternoon. Anyway, thanks very much Tom!

    I'm a little surprised there isn't a commonly-found product for this sort of thing, but then again, I get the feeling that many homeowners are intimidated by gas piping and hire pros to do it. I'm not worried because, at this stage, if my house erupts and is sent into orbit, it'd be an IMPROVEMENT! :)

    Just kiddin'.

    Thanks again!
    labman's Avatar
    labman Posts: 10,580, Reputation: 551
    Uber Member
     
    #4

    Aug 4, 2005, 01:12 PM
    The auto places that sell the valves don't speak plumber. They may call it a tank valve. At least a 3/4 '' pipe is 3/4'' pipe to everyone. Tubing is another matter. Plumbers always use ID. Many other use OD. Best to be very specific about ID and OD. I have been known to buy a pipe plug and drill a hole and tap it for 1/8'' pipe.
    dmtnhwkc's Avatar
    dmtnhwkc Posts: 1, Reputation: 1
    New Member
     
    #5

    Aug 14, 2007, 05:08 PM
    Plumbing supply stores have a gizmo (I forget the proper name of it) that is a threaded metal cap. The threaded end is usually 3/4" pipe threads. The metal body has a Shrader valve on the end (like your tire valve stem) and a gauge threaded into the side. They are made specifically for pressure testing piping. Hopefully, you can find plumbing supply people who don't look down their noses at you for not knowing proper names of stuff.
    DELMAWI's Avatar
    DELMAWI Posts: 1, Reputation: 1
    New Member
     
    #6

    Aug 8, 2008, 06:09 AM
    What is the ideal method ststement of the pipe pressure test?
    Milo Dolezal's Avatar
    Milo Dolezal Posts: 7,187, Reputation: 522
    Plumbing Expert
     
    #7

    Aug 8, 2008, 06:21 AM
    Yes: plug all ends, screw in Gas Test Gauge, take bicycle pump and pump it up. 15 lbs for 10 minutes should be fine. Home Depot, Lowe's, or Ace Hardware sells it. This is the gauge:
    Attached Images
     
    roark's Avatar
    roark Posts: 1, Reputation: 1
    New Member
     
    #8

    Nov 4, 2008, 11:21 PM

    Very helpful to see what this device looks like but... where does it go? Outside at the gas meter in line or inside at the end of a line or? In the pic above, does it connect at the end of at the right?
    Milo Dolezal's Avatar
    Milo Dolezal Posts: 7,187, Reputation: 522
    Plumbing Expert
     
    #9

    Nov 5, 2008, 12:13 AM

    You can install gas gauge anyplace on your gas system past gas meter. Let's say: you disconnect gas meter on the right side of the meter. ( don't do anything with the left side of the meter. That side belongs to the Gas Co. ). Install gas gauge right there on the stub out that used to be connected to the meter.

    Most gas meters are 3/4" but you may have bigger one, especially if you have pool heater. In this case, get reducer from the size you have to 3/4". Cap off appliances in your house and pump up the system.

    It is not OK to leave gas valves (and gas flexes) at each appliance installed during the test. These valves are designed to hold about 3psi of pressure. They will leak giving you negative reading. You will be pumping up your system to 10 to 15 psi, depending on Local Requirements. That may be 3x more than what are these appliance gas valves tested for.
    ezramace's Avatar
    ezramace Posts: 1, Reputation: 1
    New Member
     
    #10

    Jul 2, 2009, 03:34 AM
    Quote Originally Posted by Milo Dolezal View Post
    You can install gas gauge anyplace on your gas system past gas meter. Let's say: you disconnect gas meter on the right side of the meter. ( don't do anything with the left side of the meter. That side belongs to the Gas Co. ). Install gas gauge right there on the stub out that used to be connected to the meter.

    Most gas meters are 3/4" but you may have bigger one, especially if you have pool heater. In this case, get reducer from the size you have to 3/4". Cap off appliances in your house and pump up the system.

    It is not OK to leave gas valves (and gas flexes) at each appliance installed during the test. These valves are designed to hold about 3psi of pressure. They will leak giving you negative reading. You will be pumping up your system to 10 to 15 psi, depending on Local Requirements. That may be 3x more than what are these appliance gas valves tested for.
    Milo, what about the fireplace key gas valve? How much psi can that sustain? In an older home 1980?
    Milo Dolezal's Avatar
    Milo Dolezal Posts: 7,187, Reputation: 522
    Plumbing Expert
     
    #11

    Jul 2, 2009, 07:46 AM

    Good question. Old valves will not hold pressure. Same with appliance gas valves where gas flex attaches. They are designed to hold only 3psi of pressure. If you don't remove them and cap off with gal. cap - and pressurize the system - you will see drop in pressure.

    There is a bonnet-type nut at FP gas valve that is usually loose. Tighten it up all the way with socket wrench before you pressurize.

    Before you start cutting into wall to remove FP valve, do this: remove Log Lighter from inside of the FP and plug incoming gas line. Pressurize it and see if it holds pressure. If not, then cut into the wall.

    However, if you have Ball valve for Gas valve - it will hold the pressure just fine...
    iamgrowler's Avatar
    iamgrowler Posts: 1,421, Reputation: 110
    Ultra Member
     
    #12

    Jul 2, 2009, 07:53 AM
    Quote Originally Posted by Milo Dolezal View Post
    Good question. Old valves will not hold pressure. Same with appliance gas valves where gas flex attaches. They are designed to hold only 3psi of pressure. If you don't remove them and cap off with gal. cap - and pressurize the system - you will see drop in pressure.

    There is a bonnet-type nut at FP gas valve that is usually loose. Tighten it up all the way with socket wrench before you pressurize.

    Before you start cutting into wall to remove FP valve, do this: remove Log Lighter from inside of the FP and plug incoming gas line. Pressurize it and see if it holds pressure. If not, then cut into the wall.

    However, if you have Ball valve for Gas valve - it will hold the pressure just fine....
    Doesn't the UPC require all gas piping to be tested through the shut-off, which would seem to also include log lighter valves?
    RANGRAO's Avatar
    RANGRAO Posts: 1, Reputation: 1
    New Member
     
    #13

    Jul 13, 2010, 10:08 PM
    On 56" gas pipe line ( pigging facility available) how should be the hydrotesting water to be released?
    tomwiller's Avatar
    tomwiller Posts: 7, Reputation: 1
    New Member
     
    #14

    Sep 20, 2010, 01:47 AM
    I think this one is being answered already in Yahoo Answers.

    it could be leaking through the valves where you would never see the leak especially if the valves are old. In other words your valves are not 100% shut off. The pipe you ran might be fine. Use some real gas bubble leak detector. Or use straight dishsoap.
    http://answers.yahoo.com/question/index?qid=20090407000944AAxrIz8

    Also this link may help --> http://www.ci.berkeley.ca.us/contentdisplay.aspx?id=608
    teanman777's Avatar
    teanman777 Posts: 1, Reputation: 1
    New Member
     
    #15

    Apr 24, 2012, 09:33 AM
    I was told by Con Edison There was leak out side my house, they turned off the gas and fixed the leak . The hose has three meter the one on the top floor failed the pressure test'. Iwas told to get a license plumber.I don't know anything about plumbing and don't want to get ripped off. On average how much should it cost to get the pressure for that one meter to pass not fail the test
    massplumber2008's Avatar
    massplumber2008 Posts: 12,780, Reputation: 1210
    Senior Plumbing Expert
     
    #16

    Apr 24, 2012, 01:33 PM
    Hi Teanman77

    I'm sorry to say that it is simply impossible for us to even guess at such a thing.

    All will depend on costs of labor in your area as well as exactly where and how many leaks they find, right?

    Call your local plumbing inspector and ask him, "off the record" if he can recommend someone he trusts in your area, OK?

    Good luck!

    Mark

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