Welded steel pipes, also known as seamed steel pipes, are generally welded from steel plates or steel strips.

Divided into galvanized and non-galvanized. The surface is galvanized white, also known as white iron or galvanized steel pipe. The surface is not galvanized, that is, ordinary welded steel pipe, also known as black iron pipe.

Galvanized welded steel pipes are commonly used for conveying clean pipelines such as domestic water, clean air, and instrument air. Non-galvanized welded steel pipe for steam, gas, compressed air and condensate.

One is threaded at the end of the tube and the other is unthreaded at the end of the tube. Pipe-threaded welded steel pipe, each pipe length is 4 ~ 9m, welded steel pipe without thread, each pipe length is 4 ~ 12m.

Welded steel pipes vary in thickness depending on the wall:

Divided into thin-walled steel pipes, thick steel pipes and ordinary steel pipes. The most used amount on the process pipe is a common steel pipe with a test pressure of 2.0 MPa. The test pressure of the thickened steel pipe is 3.0 MPa.