Do old natrual gas pipes always leak?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Stuff, Oct 1, 2014.

  1. Stuff

    Stuff Well-Known Member

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    Backstory: Years ago the gas company came out to replace my meter and they did an inside presssure test before turning things back on. The pressure test showed leaks in multiple locations and the tech said that the test itself may have popped the seals. 1940's house with all black pipe and a traditional unfinished basement so with the easy access my plumber was done in a day replacing everything.

    Now a friend just moved in to a house built in the 50's and after smelling gas found a leak in a pipe feeding the furnace. He is fixing that now but does not want to spend money on anything else.

    So my real question is: Should I be telling him to have all the gas pipes redone a.s.a.p. because it is going to leak someplace else?
     
  2. DonL

    DonL Jack of all trades Master of one

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    May not be a bad Idea.

    Now a days they can put a poly pipe inside of the old pipe.


    Sometimes it is good if you can run fast.


    Good Luck.
     
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  4. hj

    hj Master Plumber

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    quote; Now a days they can put a poly pipe inside of the old pipe.

    Good trick IF you can do it, which is highly unlikely. Test pressures are usually 30 to 40 times, or more, higher than the operating gas pressure so a marginal connection may not leak normally but fail once the test is applied to it. It is NOT a given that old pipes will leak. It depends on the installer, the joint compound used, and the fittings. You test FIRST, THEN repair any leaks.
     
  5. asktom

    asktom Member

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    I'm with HJ but will add that it is usually the valves that leak under test pressures. It is best to remove and cap appliance shut-offs when testing.
     
  6. DonL

    DonL Jack of all trades Master of one

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    If you do install a cheap valve and it leaks it can cause problems with a appliance gas valve, if it is connected.

    Not sure if removing a valve and capping the line is a good test, Because it does not test the valve for leaks. ?

    If the test was done with the valves open, and appliances connected, You may want to get the model number of your gas valves, they may be handy to have.
     
    Last edited: Oct 2, 2014
  7. asktom

    asktom Member

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    I wasn't clear, remove the valve and cap the pipe.
     
  8. DonL

    DonL Jack of all trades Master of one

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    So remove the valve, Pass the inspection and then when the valve is installed they have a gas leak ?

    I do not think so. No go for me.

    I may be wrong. I can run fast, but do not want to, if not needed.




    Just how I roll.
     
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    If you leave the shutoff there, and it leaks past to the appliance during the test, you'll be replacing the appliance's regulator in most cases. A shutoff could leak out, but may also leak through when it is shut off.

    If there's a flex line to the appliance (and it isn't hard piped), you would need to replace the flex line when putting things back together.
     
  10. Tom Sawyer

    Tom Sawyer In the Trades

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    Hire a professional. It's cheaper than buying a new house
     
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  11. DonL

    DonL Jack of all trades Master of one

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    Yep, good advice.

    But is a inspector not a Pro ? Or just the Boss ?

    My boss just tells me how it needs to be.

    My wife is my boss.
     
  12. hj

    hj Master Plumber

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    quote; If the test was done with the valves open, and appliances connected,

    The PROPER test is done with the valves open and the flexible connectors disconnected from the appliance and capped. Test pressures can damage or destroy appliance controls.
     
  13. DonL

    DonL Jack of all trades Master of one

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    That would be the best and would check for stem leaks.
     
  14. dj2

    dj2 In the Trades

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    Sorry to say this: gas leaks must be dealt with and fixed, then tested and approved.

    Gas leaks are not like water leaks.

    A house with gas leaks is a time bomb.

    Don't shrug it off, get it fixed.
     
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