Pressure Testing Back to Gas Meter

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by jgwalter, May 26, 2011.

  1. jgwalter

    jgwalter New Member

    Messages:
    13
    Location:
    Maryland
    I need to pressure test a section of pipe. I can easily cap at the appliance ends, but need to know the method to cap at the meter end?

    Meter attachment is a union-type connection (with a rubber seal). What can I use to cap that point?
  2. Terry

    Terry Administrator Staff Member

    Messages:
    15,053
    Location:
    Bothell, Washington
    Normally you would take that fitting off and use a threaded cap.
    It would be nice to have something you could use on that end.
  3. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,216
    Location:
    Houston, TX
    Welcome to Terry's forums jgwalter,

    Yes, they have Gas Meters here, and the gas company wants to help. They would check for leaks also.

    Have a great day.

    DonL
  4. jgwalter

    jgwalter New Member

    Messages:
    13
    Location:
    Maryland
    Here is a view of the meter. I need to make a change in the line just downstream from it (about 3 feet), cutting a tee into the 1" pipe, then branching from it to a new appliance. To pressure test the pipe, I need to remove the meter, I assume by its two mounts to the mounting hanger. My question is, what kind of fitting should I find to cap that end, or do I need to remove the hanger as well. I'd rather not deal with this rusty mess, and getting the gas company to do it is an expensive challenge. I tried to get them, as part of this project, to straighten their (1967) installation, and move the meter 1 foot to the right. They wanted $1500 to do that, and would require them replacing the buried line all the way to the street, for me and my neighbor. They didn't want to mess with the old pipe.

    gas_meter.jpg
  5. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,185
    Location:
    Maine
    The gas company gets real ugly when unlicensed folks start messing with the meter. Real ugly.
  6. Terry

    Terry Administrator Staff Member

    Messages:
    15,053
    Location:
    Bothell, Washington
    I wouldn't touch that. We don't have connections like that in Washington State.
    I would soap test on the inside and leave that alone.
  7. jgwalter

    jgwalter New Member

    Messages:
    13
    Location:
    Maryland
    I sort of agree. This rusty mess needs some cleaning and paint in any case. However, removing the meter is easy. The two connections directly above the meter box are ring nuts that tighten a hose-like connection. It has a rubber washer about the size of a common garden hose washer.

    Perhaps a better question would be, as a plumber, how would you pressure test this line for a permit inspection if there is no other way to block the meter from the pressure test. (such as a valve)???
  8. cwhyu2

    cwhyu2 Consultant

    Messages:
    1,347
    Location:
    Cincinnati OH
    DO NOT MESS WITH THE METER! Need to know if you are taping in to an exsisting tee or cutting one in.
  9. SacCity

    SacCity In the Trades

    Messages:
    189
    Location:
    Sacramento, CA
    To be honest most of the time when faced with this situation I would not cut the original pipe. What's the old rule? You touch it you Own it!!!
    Normally what I do is put a Tee next to the meter and run a new line... If I'm at the end of the line I'll extend the line a few feet.

    Before you do any work on the existing gas line do a pressure test on it to ensure that there are no leaks under test conditions,
    10 psi for 15 minutes if I remember correctly.
    Thanks
    Michael
  10. jgwalter

    jgwalter New Member

    Messages:
    13
    Location:
    Maryland
    I am cutting in to an existing run. In the photo, the pipe goes through the wall, and up the other side to the ceiling of an unfinished room. My plan is to cut that pipe, remove both ends, and replace it with a new section that includes a tee and a union. That tee will feed a new 1" branch for a new cooktop about 25' away, and a future plan for a fireplace.

    Nobody seems to know how to pressure test this construction without messing with the meter in some way. I can easily valve off the three existing appliances (or cap them), but the meter end is the problem.

    I would also like to be able to blow out the residual gas before I hack into the pipe. Because of its proximity to the wall, I'll need to cut it with a saw, and not a pipe cutter.
  11. jgwalter

    jgwalter New Member

    Messages:
    13
    Location:
    Maryland
    I suppose I could come off the capped tee in the photo, and go through the wall with a second branch feed. My first thought is that would be a little odd looking, but I suppose it would work just fine, although I am still faced with the same testing issue unless I install a valve?
  12. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,689
    Location:
    Cave Creek, Arizona
    unfasten the two union nuts on the meter. They are gasketed seals. Then unscrew the "offset" coupling on the outlet (right side), from the meter bar. Screw a 3/4" plug into the opening and do your test. Afterwards reinstall the offset, connect the left hand union to the meter, then rotate the outlet offset until it lines up with the meter and fasten the second union nut. Be sure the gaskets are inside both unions and that the union nuts are tight. But, as an alternative, I might consider inserting a "JetSwet" through the plugged tee, into the pipe, and seal the line that way.
    Last edited: May 27, 2011
  13. jgwalter

    jgwalter New Member

    Messages:
    13
    Location:
    Maryland
    Thank you very much. That is exactly the kind of advice I was looking for. The meter issues don't look difficult, except for dealing with the rusty parts. However, I like the 'JetSwet' idea the best. I can also use the removal of that plug to flush the system. I am also interested to know your opinion of my cut-in plan for the branch?
  14. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,689
    Location:
    Cave Creek, Arizona
    quote; that plug to flush the system.

    What do you mean "flush the system"? You do NOT have to flush the system and I am not sure how you could do it anyway. The cut in plan is good, but what would make it a bad idea would be doing the cut in wrong. IF the union will be "accessible" then it is okay, otherwise you should not use a union.
  15. jgwalter

    jgwalter New Member

    Messages:
    13
    Location:
    Maryland
    What I meant, was after turning the gas off, to blow the residual out of the pipe with compressed air to lessen the chance of a fire when I cut through the pipe with a saw.

    Seems like a union is the only way to insert a tee into an existing run of pipe??? Correct me, if I am wrong. The section of pipe is currently exposed in an unfinished space. My plan was to add the union, a shutoff on the branch in an area that can be made accessible easily if that wall were ever finished.
  16. SacCity

    SacCity In the Trades

    Messages:
    189
    Location:
    Sacramento, CA
    Generally unions are not liked, I think that they are allowed within 6 feet of the appliance to be serviced.
    A better solution is left right nipple.

    a nipple and coupling with standard threads on one side and reversed threads on the other.
    Turn the nipple one direction and it will screw into both sides at once.

    As far as clearing the gas out of the line to cut it, I've never done so. Open up the line and blow it out with compressed air should be fine.
    Michael
    Last edited by a moderator: May 27, 2011
  17. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,689
    Location:
    Cave Creek, Arizona
    For all practical purposes there is NO GAS in the line once the meter is turned off and the pressure is drained off by any pilot lights. If the union MIGHT be inside a wall someday, then a left right nipple and coupling is the only proper method, but it is NOT something an amateur should attempt because it has to be done correctly so both sides tighten equally.
  18. SacCity

    SacCity In the Trades

    Messages:
    189
    Location:
    Sacramento, CA
    HJ - I've never used a left right nipple as most of my projects have been repipes, or minor extensions. Have avoided cutting into the center of lines thus far. In addition on my projects I have put tee's in rather than couplings in stratigic locations to alow for future expantion.

    Is there any unusual hazard with the left right nipple or just be careful to ensure uniform thread engagement on both sides?
    Thanks helping me expand my skill set
    Michael
  19. jgwalter

    jgwalter New Member

    Messages:
    13
    Location:
    Maryland
    Great advice on the union issue. At the bottom of this page (FAQ), there is a good explanation about the left-right technique: I suspect the real trick is get the measurement correct.

    "Any left- and right-hand tricks?"

    The trick for left- and right-hand fittings and couplings is to get the correct bite the first time. The way to do that is to insert one side of the nipple/coupling and hand-tighten. Count the number of turns to get it to hand-tight. Then take apart and do the same on the other side. If one side took more turns to get it to hand-tighten, then add (or subtract) that number before starting; and turn that amount into the side that took more turns. In other words, the secret is to tighten the same amount after hand-tightening.
    Last edited: May 28, 2011
  20. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,689
    Location:
    Cave Creek, Arizona
    AND, you MUST engage the second thread IMMEDIATELY, because any additional turns will screw up your calculation as to how many turns before they are equally hand tight. As I said, it is not something for an amateur to do, assuming he could even locate a left right coupling/nipple combination. Also, the left hand nipple is ALWAYS 4" long to complicate the situation.
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