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Misalignment in pre-welding of straight seam steel pipe
Jun 17, 2017

Misalignment, this is the most common problem in prewelding. Misalignment is very bad, which leads directly to the demotion or scrap of the steel pipe. Therefore, pre-welding requires strict control of misalignment. When the misalignment of the whole or half of the steel tube is poor, it is generally due to:


(1) The opening seam adjustment is not in place


(2) The joint pressure roller adjustment is not in place (the circumferential angle of the pressure roller is not correct, or the centerline of the tube is the axis, the left and right pressure roller is asymmetrical, or the relative pressure roller radial elongation is inconsistent), there is no pressure circle;


(3) Pre-bending edge is not in place, plate Benfong in the straight edge phenomenon. When the head or tail of the tube is in the wrong side, it is generally due to the error.


  • The position of the inlet and outlet roller is wrong;

  • Annular Frame center is not right;

  • The pressure roll of the joint is not good, the position deviation of individual rollers;

  • Molding is not good (after forming the tube billet on both sides of the big difference;

  • Opening seam width above 150mm;

  • Pressure fluctuation caused by hydraulic system.


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