Difference of LSAW and SSAW

Straight seam steel pipe and spiral steel pipe is a kind of welded steel pipe, they are widely used in the construction of national product, straight seam steel pipe and spiral steel pipe due to the different production process has many differences, therefore, the following specific issues about the difference between straight seam steel pipe and spiral steel pipe. Straight seam welded pipe production technology is relatively simple, the main production process with high frequency straight seam welded steel tubes and submerged arc welding and straight seam steel pipe, straight seam pipe production with high efficiency, low cost, rapid development. The strength of the spiral welded pipe is generally higher than straight seam welded pipe, the main production process is submerged arc welding, spiral steel pipe can use the same width of different diameter welded pipe billet production, can also use a narrower billet production of larger diameter welded pipe. But compared with the same length of straight seam pipe, weld length by 30 ~ 100%, and the production speed is low. As a result, a small diameter welded pipe are mostly with straight seam welding, large diameter welded pipe for the most part adopts spiral welded. They have been used in the industry production of straight steel tube located at a t-shaped welding technology, the short sections of straight seam steel pipe for docking, the length of the connect accords with the need of engineering, t the probability straight seam welded steel defect is greatly improved, and the t-shaped seam welding residual stress is larger, the stress state of the weld metal are often in a three to increase the possibility of a crack.