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6'' fire main leak detection

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  • 6'' fire main leak detection

    Normally I don't mess with leak detection anymore as it's something I don't get many calls on as slab homes are rare for me out here. but last week I was brought in to a large condo project by another plumber to help them figure out a large leak they were stumped on. asked some questions and determined that it wasn't the domestic or irrigation underground main. but it was the 6'' ductile iron fire main in the 1974 building. the line runs to 2 buildings and tees off underground at 3' deep.


    advised the plumber to get a fire sprinkler company for the repair. the hoa brings in their fire service contractor and wants to tear up the entire driveway. the plumber didn't think that was a good idea and called me to meet with the locater co. and rig up a compressor to pump up the underground. I estimated the leak to be approx. 15-20 gpm at 75psi. so a larger compressor would be needed. but I didn't want to rent a 100 cfm towable compressor so I made up a better substitute out of my 1.5hp emglow wheel barrow compressor and a returned 40 gal. water heater tank.


    75psi street pressure and I pumped up the tank to 125#. tied the 5/8'' air hose from the tank to the cheater meter hose bibb. turned off both risers in the garage to isolate the building from the underground and not trip the flow switches. there were no tamper switches on the butterfly valves. the 6'' detector check I left on as the detector check is a check valve. figured 80# into the system will overcome the 75# building pressure and I should be able to produce good bubbles. but at 15-20 gpm leak I knew I need a good reserve to keep up with the leak. the 40 gallon heater was the buffer tank that made it work.


    traced the underground first to know the path and then energized the pipe with air to make the leak amplified to search for the leak. right where I figured it was going to be. the bull head tee is the leak as per our layout. now it's just scheduling to pull up the paver driveway and dig down the 3' to expose the leak. most likely there will be a thrust block and I feel that the flange bolts have rusted causing a loosened gasket at the joint. we should know next week.


    rick
    .


    6'' detector check with cheater meter and air hose in.



    tank pressure up to 120# ready to charge line.



    air hose to bottom of tank runs to vault cheater meter.





    1.5 hp compressor runs to 40 gal surge tank. pressure as I was draining down system cleaning up. compressor and tank held study at 80 psi.


    rick.
    Attached Files
    Last edited by PLUMBER RICK; 01-22-2014, 11:13 PM.
    phoebe it is

  • #2
    Re: 6'' fire main leak detection

    Rick, You win the " smart Monkey award " Great idea using the old W'H' .
    I can build anything You want , if you draw a picture of it , on the back of a big enough check .

    Comment


    • #3
      Re: 6'' fire main leak detection

      It sure looks like a new heater to me. Still a good use of what was available.

      Mark
      "Somewhere a Village is Missing Twelve Idiots!" - Casey Anthony

      I never lost a cent on the jobs I didn't get!

      Comment


      • #4
        Re: 6'' fire main leak detection

        Rick, just did 4"fire service where the thrust block caused the failure in combination with unstable ground. As a question do you guys use standard galvanized nuts and bolts underground or do you use 316ss???????????


        My thrust block failed because the trench was over-excavated and backfilled with the spoil that was removed. No compaction and when it got wet it turned to puss. Thankyou God for giving me morons who don't know what they are doing so I can stay employed fixing these stuff-ups.........!!!!

        Comment


        • #5
          Re: 6'' fire main leak detection

          Either galvanized or sometimes just plain steel. My guess it's the bolts that are rotting and causing the leak. If so, then there will be more issues at the other joints to follow.

          Stainless would be great, but everything else is still ductile or cast iron.

          Rick.
          phoebe it is

          Comment


          • #6
            Re: 6'' fire main leak detection

            Rick is there anything in your code which requires wrapping with Denso Tape to protect the bolts from corrosion. In the old days here of the Gas Corporation they always had to wrap and bag and tape the joints. Other thing that we keep saying we cant be held responsible for is the acidity level of the soil. We have some real good arguments and fights downunder. Hey Mr Insurance man do your homework before you start chasing us................!!!!

            Comment


            • #7
              Re: 6'' fire main leak detection

              Originally posted by PLUMBER RICK View Post
              Either galvanized or sometimes just plain steel. My guess it's the bolts that are rotting and causing the leak. If so, then there will be more issues at the other joints to follow.

              Stainless would be great, but everything else is still ductile or cast iron.

              Rick.
              Monel bolting would be best. They will last forever.
              304 SS not so good for direct burial.
              316 SS is better than 304.
              316L better than 316.
              There are materials better than Monel, but you wouldn't want to pay for them.
              Monel will be about 4x the cost of 316L, maybe more depending on the market.
              Scrap Monel can bring as much as $40/pound, so take it from there.

              worked a project where we replaced some cast iron pipe which is in tidal water,
              meaning it is exposed to air and salt water as the tide goes in and out and water
              temps vary from 32 to 90°F, just about the worst condition you have. the iron was
              embritteled and spent, the Monel bolting looked like the day it was installed in the late 60s.
              "When we build let us think we build forever. Let it not be for present delight nor for present use alone. Let it be such work that our descendants will thank us for, and let us think, as we lay stone upon stone, that a time is to come when these stones will be held sacred because our hands have touched them, and that men will say, as they look upon the labor and wrought substance of them, "See! This our fathers did for us."
              John Ruskin (1819 - 1900)

              Comment


              • #8
                Re: 6'' fire main leak detection

                contractor that installed the pavers dug the line open and exposed the broken 4'' ductile pipe. interesting as it appears that there is no thrust block behind the tee. the tee is a 6'' x 4'' x 6'' . the break is about 3' away from the tee on the 4'' ductile line. sheared in half. not sure where all the water was going, but I think now that the line is off and being fixed tomorrow, our drought is solved.


                rick.







                cracked pipe with the flange of the tee off to the left of photo.







                cracked all the way through. but still looks aligned. at least from the top view.
                Attached Files
                Last edited by PLUMBER RICK; 01-27-2014, 11:05 PM.
                phoebe it is

                Comment


                • #9
                  Re: 6'' fire main leak detection

                  Rick, had one of these 20++++ years ago. What we found was a piece of shale with a pointy bit directly under and it acted similar to cracking a ceramic tile.
                  I remember this well because the Idiot principal of the primary school rings me up a few months later going off his absolute tree calling me names suggesting I was a rip-off merchant as well as many other things. He was mighty red-faced when I refreshed his tiny memory about the whole job. I think the whole job was laid straight on the bottom of the trench without packing sand or other. No timber supports under joints. But then again what would I know being a "Pro" or supposed to be..................!!!!!!!!!!!!!

                  Comment


                  • #10
                    Re: 6'' fire main leak detection

                    Originally posted by Cleanmen2 View Post
                    Rick, had one of these 20++++ years ago. What we found was a piece of shale with a pointy bit directly under and it acted similar to cracking a ceramic tile.
                    I remember this well because the Idiot principal of the primary school rings me up a few months later going off his absolute tree calling me names suggesting I was a rip-off merchant as well as many other things. He was mighty red-faced when I refreshed his tiny memory about the whole job. I think the whole job was laid straight on the bottom of the trench without packing sand or other. No timber supports under joints. But then again what would I know being a "Pro" or supposed to be..................!!!!!!!!!!!!!
                    thats exactly why you are supposed to use clean fill all around. but how many do?
                    "When we build let us think we build forever. Let it not be for present delight nor for present use alone. Let it be such work that our descendants will thank us for, and let us think, as we lay stone upon stone, that a time is to come when these stones will be held sacred because our hands have touched them, and that men will say, as they look upon the labor and wrought substance of them, "See! This our fathers did for us."
                    John Ruskin (1819 - 1900)

                    Comment


                    • Cleanmen2
                      Cleanmen2 commented
                      Editing a comment
                      Bob, I just found it, I didn't do it.............!!!

                  • #11

                    Originally posted by Cleanmen2 View Post
                    Re: 6'' fire main leak detection

                    Rick, had one of these 20++++ years ago. What we found was a piece of shale with a pointy bit directly under and it acted similar to cracking a ceramic tile.
                    I remember this well because the Idiot principal of the primary school rings me up a few months later going off his absolute tree calling me names suggesting I was a rip-off merchant as well as many other things. He was mighty red-faced when I refreshed his tiny memory about the whole job. I think the whole job was laid straight on the bottom of the trench without packing sand or other. No timber supports under joints. But then again what would I know being a "Pro" or supposed to be..................!!!!!!!!!!!!!
                    I like to take pictures of what we found. Pictures after the repair are also nice. Those pictures are then scanned into the customer file.

                    Comment


                    • #12
                      It would be nice if my pictures are still viewable in the thread I wrote.

                      Ridiculous we have to be guinea pigs for something that we've spent almost 10 years building

                      Rick.
                      phoebe it is

                      Comment


                      • #13
                        newer isnt always 'better'
                        ~~

                        ... it was plumbed by Ray Charles and his helper Stevie Wonder

                        Comment


                        • #14
                          It looks ok but the old one was better. Work on the features and leave the looks alone guys. We are all seasoned Professionals here and don't need to look sweet. We already are...............!!!!!

                          Put it back.............

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