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Seam welding I-beams and clips, details details

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  • Seam welding I-beams and clips, details details

    At our site we have a debate between structural welders and Quality control as to whether clips ( not sure if that's proper terminology ) should be welded around the entire outside that is against the I-beam without stop or interruption, or if they should be welded on all four sides but not connected at the four corners. By clip I mean a small T shaped metal piece that's welded tot he surface of an I-beam, where another I-beam would either bolt or weld to.

    Further, whether I-beam connections "end-to-end" (parallel) and "end to surface" (perpendicular) should be welded not only on the flange or/and web, but in the corners and around the edges. By corners and edges I mean where the inside of a flange meets the top and bottom of the web, and on the outside edges of the flanges themselves.

    -For Clarity
    The QC insists that a seam weld be used so that the weld doesn't stop, but that a steady bead be welded around the entire connection, whereas the welders insist that in this specific weld (and differently for others) that the corner and edge welds are unimportant and unnecessary or possibly harmful to the structures integrity.

    I'm interested in a resolution to further progress. Apparently, the instructions doesn't specify enough exactness for them. Any help given would be more appreciated if it came with some sort of resource so that I may find a "guideline" or "standard" or something.


  • #2
    This is a structural engineering question, that is who specifies the weld detail as it involves the design stress of this structural component. A weld engineer would qualify the weld for that stress level, usually the WPS and PQR will have strength in excess of the base with no ill-mannered heat affected zone behavior in guided bend or bend tests for structural steels. Unless you are working on extremely thick sections or high strength low alloy materials, the welds aren't an issue.

    A picture of the item in question would go a long way here. Still a bit confused on the purpose of the clips.


    • #3
      We did a structural building, just one story, inside a meat factory with a very high ceilling.So we put this structure inside to make a second floor.
      So support beam all around and cross beam and cross beam between the cross beam "" if it makes any sense. the way I'm explaining, but it was engineered and there was no beam welded completely to each other.
      the only members welded were the tabs with the 6 holes to receive the end of the beam that was notch top end bottom and bolted to the web. The tabs were the only thing welded to the beam.


      • #4
        As simple as I see it is:

        Weld to what the details on the print say. If the weld detail calls for all the way around, weld all the way around-- without interuption.

        If you leave gaps in the weld at each corner, I would think you would be increasing the potential for notching stresses on the weld.

        Any structural work that I have done it wasn't up to the welders what weld to put in, it was very clear on the blueprint. Some I-beams were welded all the way around and some were fish-plated into the walls/connecting beams, with welds made only to the web of the beam.

        Look at the drawings and see if there is some clarity to be found there. Don't mess with an engineered structural-- join it according to the weld details on the print.
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        • #5
          I`m with wronghand,

          your responsibilties are the plans, weld symbols. You cant go wrong following
          the prints and wps.

          old but new


          • #6
            I third, wronghand

            When I was welding a lot of I-beams, we did what the plans said because that was from someone in engineering. We used dual shield and we were in agreement that we welded from the end corners to the middle of the clip, so 2 starts, 1 overlapping stop, and you have a fully welded clip.


            • #7
              Thanks for the replies, though without resources of any sort.

              The clips were as described by Daniel.

              As I stated, the blueprints did not specify, and so the Quality control and the welders were discussing it. On most other welds, it was crystal clear, but this tiny bit was unclear.

              The statement by Wronghand "If you leave gaps in the weld at each corner, I would think you would be increasing the potential for notching stresses on the weld." was somewhat useful.

              This issue has been resolved. The Quality Control as demanded that it must be seam welded all the way around including the corners because that is his wish and he ultimately is liable for the weld quality.

              Again, thank you very much for the replies, your time, and insight.


              • #8
                This true especially this welding is highly engineered, on a lot of general fab work it might not amount to much, lots of connections are not 100% of what they could be and don't need to be. Sufficient is a good word in many cases. If its well designed it could be the welding is simply to keep things from sliding apart and the real stresses are along the length of the member, etc, Real equalizations for sure though. I weld and bolt a beam in my office for second story, it bears on a post, sits on a block wall and the weld really doesn't do much except hold it all in place while the rest of it was framed, could have had near the worlds worst with the HF 90A mig do it.


                • #9
                  Originally posted by David1101 View Post
                  As I stated, the blueprints did not specify, and so the Quality control and the welders were discussing it. On most other welds, it was crystal clear, but this tiny bit was unclear.
                  Who is "Quality Control"? this should have been a question for the engineer of record, not a weldor or an "inspector".... If the prints are not clear, an RFI should have been send to the engineer who's stamp is on the plan....
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                  • #10
                    ^Agreed, I'm no expert, but most QC guys (at least where I work) just make sure you are following weld procedures. If there isn't a weld spec on the plan, I don't think QC would or should have anything really to do with it. Any questions about design are directed towards engineers.