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  • Gas Leak

    I get called out to a gas leak at a restaurant this morning. The gas company tagged the shut off valve under the steam table. I told them I will be back this evening to work on the leak that was tagged.

    Well I get there at 10 pm and fired up my gas sniffer. I sniffed all around the gas valve and the pipes under the bottom shelf of the steam table and I was not reading any leaks. I then sniffed the 90º elbow that was about 20" up from the floor that leads into a tee on the run of the tee it leads to the first burner with a union. The branch pointed to the left which lead into another compartment, in the other compartment there was a 45º elbow a 6" nipple then another 45º elbow then a long length of pipe that lead to another union then to a burner. Now while sniffing around the tee the sniffer went off, around the first union on the run it went off, and around the 45º elbows in the other compartment it went off. We took apart all the pipes from the two unions and removed the tee. Turns out whom ever put this stuff together was afraid to tighten the fittings onto the pipe every joint that had a leak was only threaded in by two threads. So after changing out the pipe and fittings and reassembling the pipe we turned the gas on. I hear a huge leak I run the sniffer all around trying to find it but the pipes under the table, and the pipes we redid were all fine. That only leaves the riser pipe that brings the supply from under the shelf to under the table. My brother sticks his head in there and notices they have the foam insulation wrapped around the pipe a few inches above the 90º he removes it and finds tons of rust and a big old crack in the pipe.

    So here is a picture of the pipe. I turned the gas off for now, will be heading back to replace this all in the morning.

    Attached Files
    Ron Hasil Lic #058-160417
    A-Archer Sewer & Plumbing specializing in:
    Tankless Water Heaters | Drain and Sewer Cleaning
    Sump and Ejector Pumps | Backflow RPZ Testing

  • #2
    Re: Gas Leak

    ron, being above ground was it just years of dripping water on the steel pipe?

    rick.
    phoebe it is

    Comment


    • #3
      Re: Gas Leak

      Originally posted by PLUMBER RICK View Post
      ron, being above ground was it just years of dripping water on the steel pipe?

      rick.
      That what it seems like. These steam tables are original to this place which has been standing since 1960. I am lucky I got my brother to help me on this, I can not fit in there to tear this stuff out. I will get more pictures in the morning once I get all this stuff tore out.
      Ron Hasil Lic #058-160417
      A-Archer Sewer & Plumbing specializing in:
      Tankless Water Heaters | Drain and Sewer Cleaning
      Sump and Ejector Pumps | Backflow RPZ Testing

      Comment


      • #4
        Re: Gas Leak

        Obviously that is exposed to moisture, so maybe a piece of ss flex gastite pipe, might work better? Let us know what you do. Surprising that place didn't blow up.

        Comment


        • #5
          Re: Gas Leak

          Maybe it didn't blow up because they have great ventilation and natural gas rises so it got sucked out.

          If I recall, natural gas is only combustible in the air when it's in a concentration between 15%-25% of the atmosphere.

          Of course this doesn't explain why they didn't have a gas buildup at night and morning when vent fans aren't operating.

          They ARE lucky.
          Time flies like an arrow.

          Fruit flies like a banana.

          Comment


          • #6
            Re: Gas Leak

            Originally posted by geno gardner View Post
            Maybe it didn't blow up because they have great ventilation and natural gas rises so it got sucked out.

            If I recall, natural gas is only combustible in the air when it's in a concentration between 15%-25% of the atmosphere.

            Of course this doesn't explain why they didn't have a gas buildup at night and morning when vent fans aren't operating.

            They ARE lucky.
            i've always used 4-14%.

            chances are the leak wasn't that bad until they started to wrench the new stuff and disturbed the old pipe. 8'' water column is not much pressure.

            rick.
            phoebe it is

            Comment


            • #7
              Re: Gas Leak

              We replaced it with a new piece of pipe. cut and threaded a new 16" piece. Here is a pic of it after I removed it. It is under the steam table with a built in hand sink which had a leaking faucet at one time. I suspect thats where the moisture came from. Plus the fact some one thought it was a good idea to put a short piece of foam pipe insulation right around the pipe where you see all the corrosion.




              Attached Files
              Ron Hasil Lic #058-160417
              A-Archer Sewer & Plumbing specializing in:
              Tankless Water Heaters | Drain and Sewer Cleaning
              Sump and Ejector Pumps | Backflow RPZ Testing

              Comment


              • #8
                Re: Gas Leak

                looks like sec 10 pipe
                Charlie

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                http://observatory.mountwashington.o...nal&fr_id=1040


                http://www.mountwashington.org/weather/conditions.php

                new work pictures 12/09
                http://public.fotki.com/hvachawk/

                Comment


                • #9
                  Re: Gas Leak

                  Go Galvy!

                  Comment


                  • #10
                    Re: Gas Leak

                    You mean the foam insulation around the pipe didn't fix the leak? Some people have no business in the field. Nice piece of pipe for the "oh no" collection.

                    Comment


                    • #11
                      Re: Gas Leak

                      Originally posted by Birddoggiest View Post
                      Go Galvy!

                      That got me thinking. Is galvanized piping and fittings legal to use for gas in other states? Here in Minnesota it's illegal for all gas piping.

                      Comment


                      • #12
                        Re: Gas Leak

                        Depends on location...here we go again! NFPA 54 states that gas pipe must have a melting point of no less than 1500F. Zinc melts at just under 800F. You cannot prove that your galvy pipe is intact because the steel is good or the steel is flawed and the zinc makes it look good on a pressure test. It really should not be used. Also note that NFPA 54 ends as soon as you are outside of the house.

                        Comment


                        • #13
                          Re: Gas Leak

                          From what I learned over the years Black pipe only for gas here. Well unless you use the CSST crap.
                          Ron Hasil Lic #058-160417
                          A-Archer Sewer & Plumbing specializing in:
                          Tankless Water Heaters | Drain and Sewer Cleaning
                          Sump and Ejector Pumps | Backflow RPZ Testing

                          Comment


                          • #14
                            Re: Gas Leak

                            Originally posted by Kevin Jones View Post
                            Depends on location...here we go again! NFPA 54 states that gas pipe must have a melting point of no less than 1500F. Zinc melts at just under 800F. You cannot prove that your galvy pipe is intact because the steel is good or the steel is flawed and the zinc makes it look good on a pressure test. It really should not be used. Also note that NFPA 54 ends as soon as you are outside of the house.
                            here we go again with gal pipe.

                            gal pipe is legal where i work. in fact the gas company uses gal pipe fittings and nipples at there meters that are close to the beach.

                            remember that the gal/ zinc coating is only the plating. not the real pipe. why do you think that wrench marks and threaded joint rust on gal pipe.

                            because you damaged, cut off the gal. plating. the pipe under the plating is black steel.

                            rick.
                            phoebe it is

                            Comment


                            • #15
                              Re: Gas Leak

                              Originally posted by PLUMBER RICK View Post
                              here we go again with gal pipe.

                              gal pipe is legal where i work. in fact the gas company uses gal pipe fittings and nipples at there meters that are close to the beach.

                              remember that the gal/ zinc coating is only the plating. not the real pipe. why do you think that wrench marks and threaded joint rust on gal pipe.

                              because you damaged, cut off the gal. plating. the pipe under the plating is black steel.

                              rick.
                              The last time I checked...meters go on the outside of a building. NFPA 58 has jurisdiction there. I fully agree with galvy outside and especially in a salt environment.

                              The fact that zinc is only a coating is the entire point. Thank you. A seam fault in a pipe can be sealed over by zinc and hold a good test while still being an unsafe section of pipe.

                              Inside of a building should only be done in black iron or CSST. Capital Period

                              Comment

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