Types and uses of welded steel pipes

Carbon steel welded pipes can be divided into three types: Longitudinal submerged arc welded steel pipes (LSAW), Spiral welded steel pipes (SSAW), and Electric resistance welded Steel Pipe (ERW, also called high-frequency straight seam welded steel pipes ) .

1. LSAW steel pipe

Longitudinal submerged arc steel pipe (LSAW pipe) is a steel pipe with a weld seam parallel to the longitudinal direction of the steel pipe. It is made of hot-rolled or cold-rolled steel plates or steel strips that are curled and welded. The production process of straight seam welded pipe is simple, the production efficiency is high, the cost is low, and the development is rapid. Straight seam steel pipes are widely used in water supply projects, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, and urban construction.

2.SSAW steel pipe

Spiral welded steel pipe (SSAW pipe) is made of strip steel coils as raw materials, rolled into tube blanks at a certain spiral angle, and then welded together. It can use narrow strip steel to produce large diameters steel pipe. Spiral steel pipes are mainly used in drainage and water supply projects, fluid liquid, and solid transportation pipelines. It is widely used in urban construction and municipal engineering.

The strength of spiral welded pipes is generally higher than that of straight seam welded pipes. Welded pipes with larger diameters can be produced from narrower billets, and welded pipes with different diameters can also be produced from billets of the same width. However, compared with straight seam pipes of the same length, the weld length is increased by 30~100%, and the production speed is lower.

3.ERW steel pipe

Electric resistance welded steel pipe (ERW pipe) uses the skin effect and proximity effect of high-frequency current to heat and melt the edge of the pipe blank after the hot rolled coil is formed by a forming machine, and presses it under the action of a squeeze roller Welding to achieve production. ERW has the characteristics of high efficiency,low cost,material saving and easy automation,it is widely used in aviation, aerospace, energy, electronics, automotive, light industry and other industrial sectors, is an important link in the welding process.