The Advantages and Disadvantages of Spiral Welded Steel Pipe

The sprial welded steel pipe is formed by spiral bending of strip steel or coiled plate and is welded with double-side submerged arc welding. The steel pipe is widely used in water, electricity and chemical industry for the following reasons. 1) As long as the change in forming angle, you can use the same width of the strip production of various diameter steel pipe, easy to transfer type.2) Because it is continuous bending, so the length of spiral pipe length is not restricted, the length can be arbitrarily set.3) Weld spiral evenly distributed throughout the circumference of the spiral tube, so the size of the spiral tube high precision, strength is also strong.4) Easy to change the size, suitable for small quantities, more varieties of the production spiral.Spiral steel pipe with the same specifications than the straight seam welded pipe length, the same specifications wall thickness, the DSAW steel pipe to withstand the maximum pressure. The defects of the spiral steel pipe weld are "oblique defects". In the course of use, the principal stress direction of the steel pipe, that is, the equivalent defect length in the axial direction of the steel pipe is smaller than that of the straight pipe. Secondly, since the structural steel pipe is rolled steel plate, the impact toughness has larger anisotropy, The CVN of the direction can be three times higher than the CVN value perpendicular to the rolling direction.