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  • Cracks

    Need help, stuggeling to past radiographic testing on sch 40 10" and 12" pipe. We have gone back into these welds 4 times now and wonder if the metal is now bad. Using Linclon 5P+ and Linclon 7018 excalaber. Now the simple repairs are producing 2-3" cracks.

  • #2
    Paul, The group is going to want more info to answer your question; Like how hot are you running? Is this "new" pipe? or is it just a repair to old pipe? Are you pre-heating and post heating? Have you used the same rod on all repairs; is the rod bad? I know all these sound simple, but after watching the group for a few months they will want more information to diagnose the problem.

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    • #3
      Cracks

      Sorry but I'm not the welder, just the project manager that is geting his #$% kicked form rewelding and testing cost. Looking for any advise, the pipe is new and we haven't been doing any pre or post heating although what I can find googling this might help. The temps hear in San Antonio are lows 70 and highs 85, do we still need to preheat?

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      • #4
        Wouldn't hurt to preheat. His he trying to fill this groove with less passes. smaller beads with not much weaves are less prone to cracks then big hot passes.
        Passes shouldn't be much wider then 3 times the size of the rod.

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        • #5
          What grade of pipe are you working with and are your welders following an appropriate welding procedure?

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          • #6
            Black pipe or pipe with some chrome in it that looks like black pipe until welded. I have seen that...Bob
            Bob Wright

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            • #7
              Originally posted by [email protected] View Post
              We have gone back into these welds 4 times now and wonder if the metal is now bad..
              The metal shouldn't have "gone bad". Any time you go back to make a repair you should pre-heat, unless the ambient temp is in the 300-350 range, so 70 just won't do it. Also, not sure what code you are required to meet, but I believe a repair on a crack can be made one time only. After that, grab a new piece of pipe.
              Miller Syncrowave 200
              Homemade Water Cooler
              130XP MIG
              Spectrum 375
              60 year old Logan Lathe
              Select Machine and Tool Mill
              More stuff than I can keep track of..

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              • #8
                What time of day was this?
                Was it early in the morning? Was it preheated to get rid of the moisture?
                Thinking of moisture INSIDE of the pipe accumulated during the night.
                You talked about temps during the day but at night in the desert it can get very cold.
                If the pipe was dry when delivered because air was flowing all around it but when it is on the ground or in a ditch it can gather moisture inside.
                Did you use brand new sealed package of rods for the repair?
                The structural welding code for those rods says only 4 hours can the rods (E7018)
                be exposed to atmosphere before rebaking and only can be rebaked ONE time.

                Which way were the cracks?
                Did you repair the root and if so with what? Did you redo the root with the correct electrode? Just asking.
                A cracking joint can also be from too wide of a gap.

                Sure wish we could see a photo of those cracks.
                Like you know a root opened up a little too far by grinding?
                Last edited by Donald Branscom; 03-22-2011, 11:26 PM.

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                • #9
                  From a book by Hoobasal Rampaul online.

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                  • #10
                    this is most likely not your answer but i remember a bunch of pipe that we had to weld up had lamination in it, it was bad before we touched it

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                    • #11
                      any chance the pipe is magnatized? if so the welds will crack unless you demagnatize it . try wraping the lead around it while welding.

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