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  • #16
    Re: Gas line pressure tests

    It upto the administrative authority at their discretion for a gas test and lenght of time.

    I had an inspector do a 24 hour test on a building we did with a 4" main. Still only a 10# pound test, but 24 hours and he sealed the gauge so it couldn't be touched.

    On medium pressure gas we had to do 75# test. Also on welded systems too.

    Temperature changes will only affect an overnight or extended test. Ive seen pipe dope fail with temperature extremes on different materials. Like steel to aluminun on seismic gas shut off valves years later.

    Rick.
    phoebe it is

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    • #17
      Re: Gas line pressure tests

      Originally posted by PLUMBER RICK View Post

      I had an inspector do a 24 hour test on a building we did with a 4" main. Still only a 10# pound test, but 24 hours and he sealed the gauge so it couldn't be touched.
      This was our first 24 hour test, as the gas company had to lay over 1,100ft to get the gas line from the street to the house. They required 60psi...we gave them 100.

      Comment


      • #18
        Re: Gas line pressure tests

        Originally posted by Flux View Post
        My father is one of those guys who is scared to death of a lawsuit, and he protects his *** as much as possible. When we finished that gas job the other day, I was like "why are we putting 100psi in ?" His response was.." I want peace of mind".

        So we did it, and we both crawled all over the place checking our fittings with the system full.




        Over the last 5 years...I'm getting more calls for fixing gas leaks after the gas company has red tagged the system. In most cases I find that a fitting wasn't tight enough or a pitted cast fitting.
        Flux ,because of an occasional sand casting pin hole on black iron fittings,I use nothing but Galvy fittings on both black iron and Galvy pipe. Especially ,with import fittings, Credit "Plumbing a house By Peter Hemp " Awesome Plumbers Book.
        I can build anything You want , if you draw a picture of it , on the back of a big enough check .

        Comment


        • #19
          Re: Gas line pressure tests

          Years ago I had about a 100 ft of new gas line in a trench Next to a large retaining wall we built. I charged the system in the morn for afternoon inspection. It was a hot summer day. Walking By the riser I was shocked by the pressure increase ! Then realized, Mr. Sun was Playing with Me.
          I can build anything You want , if you draw a picture of it , on the back of a big enough check .

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          • #20
            Re: Gas line pressure tests

            I test at 100lbs. first and drop it to 15lbs for the inspection but ultimately the test pressure is up to whatever the inspector wants. I generally test the lower pressure with a Rogers gauge which is very accurate and very expensive, however a simple and inexpensive manometer works just fine and will show very very small leaks in a matter of a few minutes at most.
            sigpic

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            • #21
              Re: Gas line pressure tests

              I thought everybody had to use these...LOL

              I still have to use these guys, I have found that I cant leave them in the truck as the bouncing will knock them out of calibration, Oh and ANY leak that would equal a mouse fart will show up on this gem.

              https://www.ridgidforum.com/forum/t34944/

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              • #22
                Re: Gas line pressure tests

                Originally posted by OkieBill View Post
                I thought everybody had to use these...LOL

                I still have to use these guys, I have found that I cant leave them in the truck as the bouncing will knock them out of calibration, Oh and ANY leak that would equal a mouse fart will show up on this gem.

                https://www.ridgidforum.com/forum/t34944/
                I never heard of a special gauge for gas testing until this forum. Maybe the city of Philadelphia is different, but where I live there is no such requirement.

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                • #23
                  Re: Gas line pressure tests

                  Originally posted by theplungerman View Post
                  15 pds for 15 mins gets it done in long beach Ca. Inspector isn't gonna hang around longer then that.
                  100 pds? , wow
                  Gotta agree, 100lb is real gutsy if you dont need to do it. If you are looking for failure I would suggest you are going the right way

                  Comment


                  • #24
                    Re: Gas line pressure tests

                    Originally posted by blue_can View Post
                    I don't believe the explanation is as simple as mentioned - the tire examples have two variables - pressure and volume. For a given pressure what Rick said is correct - however if you consider a fixed size hole through which a leak will occur something at a higher pressure will force itself out faster and more volume will be dispelled than at a lower pressure so you will probably see the leak on a gauge with less precision since you should have more pressure loss.

                    However, as per the gas code there is no 100# test - everything is done at much lower pressures so if I were an inspector I would want to see the test done as prescribed in the code.

                    Another thing to bear in mind especially on a low pressure test is that if you do an extended one say overnight the drop in temp can affect the pressure which can appear to be a leak but in actual fact is not. I've seen it happen plus it is also mentioned in the gas code handbook.
                    Over here we are a little prehistoric. We use this thing called a Manometer which is a tube half filled with water. When you apply pressure on one side it pushes the other up. If there is a leak then the water seems to level out. I think it was a Plumber who invented this too but we let the Engineers write the procedure..................ehehheheheeehhhheeeeehe ehheheehe

                    Comment


                    • #25
                      Re: Gas line pressure tests

                      Originally posted by PLUMBER RICK View Post
                      It upto the administrative authority at their discretion for a gas test and lenght of time.

                      I had an inspector do a 24 hour test on a building we did with a 4" main. Still only a 10# pound test, but 24 hours and he sealed the gauge so it couldn't be touched.

                      On medium pressure gas we had to do 75# test. Also on welded systems too.

                      Temperature changes will only affect an overnight or extended test. Ive seen pipe dope fail with temperature extremes on different materials. Like steel to aluminun on seismic gas shut off valves years later.

                      Rick.
                      One of the greatest downfalls in our industry here has been the loss of knowlege and skill-set. years ago with a job like this one Rick we would have a chart recorder on the installation for 24hrs minimum. Thjis would give a true indication and quickly too. Records the rise and fall with night and day temperature difference. Now they have become horrendously expensive and unless you are doing big installs not worthwhile. Second hand ones, well the guys with them got the smarts real quick and are nearly as expensive as a new one

                      Comment


                      • #26
                        Re: Gas line pressure tests

                        Originally posted by Cleanmen2 View Post
                        One of the greatest downfalls in our industry here has been the loss of knowlege and skill-set. years ago with a job like this one Rick we would have a chart recorder on the installation for 24hrs minimum. Thjis would give a true indication and quickly too. Records the rise and fall with night and day temperature difference. Now they have become horrendously expensive and unless you are doing big installs not worthwhile. Second hand ones, well the guys with them got the smarts real quick and are nearly as expensive as a new one
                        More expensive? Old paper chart recorders are pretty much worthless around here. I don't know whay anyone would want one today as the maintenance is prohibitive.

                        Everything has gone digital here and there are many options that are reasonable in price. There are even digital pressure gauges that will record high/low readings for recall later, so they could be used to document pressure rises or drops overnight say. You can get a calibrated datalogger with a pressure transducer for a couple hundred bucks. If your gauge, unless its a manometer or similar primary standard, should be calibrated as called out in the code, and the gauge range can not exceed 5x the test pressure IAW 2003 IFGC which is the copy I have with me, I doubt the requirements have changed in the later versions.


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                        Last edited by Bob D.; 01-26-2013, 08:29 AM.
                        ---------------
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                        “If I had my life to live over again, I'd be a plumber.” - Albert Einstein
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                        • #27
                          Re: Gas line pressure tests

                          Originally posted by Cleanmen2 View Post
                          We use this thing called a Manometer which is a tube half filled with water.
                          I carry a manometer on my truck

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                          • #28
                            Re: Gas line pressure tests

                            E bay new manometer $47.77 voit gm35 any comments
                            I can build anything You want , if you draw a picture of it , on the back of a big enough check .

                            Comment


                            • #29
                              Re: Gas line pressure tests

                              Originally posted by Cleanmen2 View Post
                              Over here we are a little prehistoric. We use this thing called a Manometer which is a tube half filled with water. When you apply pressure on one side it pushes the other up. If there is a leak then the water seems to level out. I think it was a Plumber who invented this too but we let the Engineers write the procedure..................ehehheheheeehhhheeeeehe ehheheehe
                              I had no idea who invented the manometer but I looked online and apparently it was Otto von Guericke - a German scientist in the 1600s.

                              I'm also somewhat prehistoric - I have a cheap $20 water manometer for taking gas pressure readings. I would probably buy a digital one if I did this kind of thing for a living.

                              The principle of the water manometer (U-tube manometer) is very simply – you fill a tube open at both ends with water and when both ends are exposed to atmospheric pressure the water level in both is the same. This can also be used as a level.

                              If you pressurize one end the water gets pushed up by a certain amount. Here in the US we use “WC to refer to this pressure and that’s the number of “ the water gets pushed up by. In the SI system of course this would be measured in bars or millibars.

                              For me in addition to doing the 15# test I also typically use a manometer to check for leaks by pressurizing the system and then shutting the gas off and monitoring the system pressure with the manometer. I also use my manometer to measure the static gas pressure if I need to size gas lines. I have all the gas lines in my home modeled on an Excel spreadsheet. By taking the static gas pressure if I need to add new lines etc I can plug the static pressure into my spreadsheet and size the gas line so that at full flow the pressure at the appliance does not drop below the recommended minimum. It an alternative and more accurate computation than using the gas tables which most people do. My spreadsheet is based on the actual gas flow formula.

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                              • #30
                                Re: Gas line pressure tests

                                Great info! Thanks BC
                                I can build anything You want , if you draw a picture of it , on the back of a big enough check .

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