The coil owing to rolling direction of spiral welded pipe isn't vertical pipe axis and plate rolling direction perpendicular to the axis of the steel pipe direction, therefore, opposed cracking performance is healthier than that of spiral welded pipe.
From the fastening method, fastening methodology and uniform spiral welded pipe inevitably there'll be plenty of T weld, therefore there square measure probabilities of fastening defects square measure greatly improved, and also the formed seam fastening residual stress of weld metal, usually in 3 dimensional stress state, increase the chance of cracks. Moreover, in line with the provisions of the submerged arc fastening method, every weld shall be at the arc and arc ending, however every longitudinal welded pipe in girth fastening, can't meet the conditions, leading to the arc fastening defects could have a lot of.
When the pipe is underneath internal pressure, 2 main stresses square measure typically generated within the pipe wall, that is, the radial stress Delta Y and also the axial stress Delta X. The synthesis of Y1/2, that is that the angle of the welded joint of the spiral welded pipe. Spiral welded pipe seam angle is 50-75 degrees, therefore the stress synthesis of spiral weld seam welded pipe is principal stress 60-85%. within the same work harassed, with a diameter magnitude relation of spiral welded pipe welded pipe wall thickness may be reduced.
Manufacturers will use a similar dimension of the strip steel to provide a spread of diameter steel pipe. The flatness of pipe is nice, the scale of it's a lot of correct, the spiral weld within and out of doors will increase the rigidity of pipe body, therefore the production method of SSAW steel pipe does not want size and straightening method when fastening. straightforward to attain mechanization, automation and continuous production. Compared to different equipments those have similar size, it's alittle size, tiny footprint and investment, and quick construction. Compared with a similar size of the straight seam welded pipe, the weld seam per unit length of tube stock is relatively long, that makes spiral welded pipe production has lower productivity.