Straight seam steel pipe and spiral steel pipe

Process quality overall performance of straight seam steel pipe is better than spiral steel pipe. At present, the domestic production of straight seam steel pipe are: nominal diameter DN400 and below the high-frequency ERW steel pipe, nominal diameter DN400 above for LSAW steel pipe. For LSAW steel pipe, according to different molding process, a total five different ways of UOE, JCOE, HME, RBE and PFP, the former two are the most common. Because UOE forming welded steel pipe production line is with high molding equipment technology content, high production efficiency, molding process is relatively simple, good shape, and a small welding stress after forming ; and because of the overall expansion of production used in hydraulic diameter steel pipe can effectively eliminate stress, improve the pipe strength and dimensional accuracy, so the quality is better than JCOE forming welded steel pipe.