HSAW pipes (spiral submerged arc welded pipe),is mabe of hot-rolled strip steel and bending formed according to spiral, automatic submerged arc welding carried out within the seam and the outer seam welded spiral seam steel pipe (also known as spiral welded pipe, spiral pipe, spiral steel pipe). As for the following reasons, it is widely used in the production of large diameter steel pipe:
1) changing the shape angle, you can use the same width strip production various calibres steel pipe;
2) because it is a continuous bending, the length of steel pipe length is unlimited;
3) weld spiral-shaped uniform distribution on the circumference of the entire steel pipe, steel pipe size, high precision, high intensity;
4) easy to change the size suitable for small quantities of steel pipe production of many varieties.


Spiral weld seam straight tube length, tube length L, the weld length is L / cos (8). For a long time debating the spiral and straight seam pipe, in particular, who is superior compared with the UOE steel pipe. Spiral pipe manufacturing technology to today, we should be comprehensive and correct evaluation and comparison, the idea of ??a long spiral weld.


First of all, due to defects in the weld parallel, for the spiral pipe, the weld defects is as "oblique defects". During use, the principal stress direction of the steel pipe, the pipe axis direction of the equivalent defect length is samll than a straight seam pipe is small; Secondly, since the pipeline steel are rolled plate, impact toughness large anisotropy along the rolling direction CVN value than perpendicular to the rolling direction of the CVN value three times higher. Straight seam pipe suffered by the main stress is precisely perpendicular to the direction of the lowest pipe impact resistance, while the spiral is to stagger the lowest in the direction of the pipe impact resistance, so that the spiral weld disadvantages into advantages.