Classification of welded steel pipe

　Strength is generally higher than that of straight seam welded steel pipe. Large diameter welded steel pipe can be produced with narrow blanks, and different diameter welded steel pipe can also be produced with blanks of the same width. However, compared with the welded steel pipe of the same length, the weld length is increased by 30~100% and the production speed is low. Therefore, small diameter welded steel pipe are mostly welded longitudinally, while large diameter welded steel pipe are mostly spiral welded.

　　Welded steel pipe is divided into two types: automatic submerged arc welded steel pipe and high frequency welded steel pipe.

　　The spiral seam automatic submerged arc welded steel pipe is divided into two categories: API 5L X60 LSAW Welded Steel Pipe are generally welded with ordinary carbon steel Q235, Q235F and common low alloy structural steel 16Mn. welded steel pipe with Q235, Q235F, Q195 and other steels and used as low pressure fluid conveying pipes.

　　There is no uniform product standard for spiral seam high frequency welded steel pipe, which is generally made of common carbon steel Q235, Q235F and other steel.