Electric resistance welding, or ERW, is a welding technique that produces pipes with a more precise surface by just heating the edges. Pipes up to 0.4 m in diameter might be manufactured more affordably in this way. The difference between seamless pipes and welded pipes are mainly the different in molding process where seamless pipes are generally the molten steel through the annular slit of the backlog by stretching out before treatment processes.They are utilized for a variety of engineering reasons, including sewage, gas pipelines, LPG and other non-toxic gases, etc., as well as agricultural and irrigation.