During the forming process, the steel plate deforms evenly, the remaining stress is small, and the skin phase is not scratched. The processed spiral steel pipe has greater flexibility in the size and specification of the diameter and wall thickness, especially in the production of high-grade steel-grade thick-walled pipes, especially the small and medium-diameter thick-walled pipes have disadvantages that cannot be compared with other processes. To meet users' more requirements in terms of spiral steel pipe specifications.

Spiral steel pipes should be subjected to mechanical performance test, flattening test and flaring test before leaving the factory, and must meet the requirements of the standard. The quality inspection methods of straight seam steel pipes are as follows:1. Judging from the surface, that is, in appe