Longitudinal Submerged Arc Welded Pipe or simply LSAW steel pipe and Straight Seam Submerged Arc Welded Pipe or simply SSAW steel pipe belong to submerged-arc welding (SAW). But LSAW steel pipe adopts single steel sheet as raw material, its advantages include: the thickness of the steel plate can reach more than 100mm, and there is no crescent bends; since it is straight seam, forming is more convenient, but also it is easy to weld tracking, which is suitable for two-step pre-precision welding production; and there is the whole body of mechanical expansion process, which can basically eliminate the residual stress. All of advantages above make LSAW can be produced big diameter steel pipe (the maximum can reach 1422mm), high-grade pipe (50mm), high steel grade (X80/X100/X120), and large structure tube that used in two, three, four types of regional and marine engineering. LSAW steel pipe and high-frequency Longitudinal Welded Pipe (HFW steel pipe) all belong to Longitudinal Welded Pipe, but the high-frequency welded pipe can be made of medium and small welded pipe (400mm), and there is intermediate frequency heat treatment process. When the diameter, steel grade is the same, high-frequency welded pipe is more superior, for example, foreign pulp pipe often use high-frequency welded pipe (HFW).
LSAW steel pipe has obviously advantages in the application of land long-distance pipeline. For example, China's West-East Gas Pipeline 1219mm, X80 steel-grade gas pressure 12MPa with SSAW steel pipe wall thickness of 18mm; when 1422mm, X100, gas pressure 12MPa, the thickness of SSAW steel pipe is 15mm, but the thickness of LSAW steel pipe can reach more than 30mm. LSAW steel pipe is also widely used in marine engineering. However, LSAW steel pipe needs to learn from high-frequency Longitudinal Welded Pipe on the weld (including heat affected zone) heat treatment process, and need to add heat treatment equipment in the process.
At present, China's LSAW steel pipe development X100 grade is still in the trial production stage, in addition to the quality of raw materials hot rolled plate to be improved, the pipe technology of LSAW steel pipe also should be further studied, one of which is adding heat treatment equipment, doing heat treatment to the weld zone 2 and the whole tube, to improve the mechanical properties of LSAW pipe. In this regard, pipe manufacturer (Prime Steel Pipe) can refer to the finishing process of seamless steel pipe. At present, pipe manufacturer Prime Steel Pipe provides a large number of LSAW steel pipe for sale, if you are interested in our high-quality carbon steel pipe, you can get more details about steel pipe price list by click the hyper-link.
