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.
Date：2012-06-08 14:12:14 From：www.hnssd.com