The blank used for welded steel pipe is steel plate or strip steel, which is divided into welded boiler pipe and electric welding (resistance welded) pipe due to different welding processes and automatic arc welding pipe. According to welding forms, it is divided into two types: straight seam welded pipe and spiral welded pipe. Because of its end shape, it is divided into round welded pipe and special-shaped (square, flat, etc.) welded pipe. Welded pipes are divided into the following varieties due to their different materials and uses:

GB / T3092-1993 (galvanized welded steel pipe for low-pressure fluid transportation). Mainly used for conveying water, gas, air, oil and heating hot water or steam and other generally low-pressure fluids and other use pipes. Its representative material is: Q235A grade steel.

GB / T3091-1993 (galvanized welded steel pipe for low-pressure fluid transportation). Used for conveying water, gas, air, oil, heating hot water or steam and other generally low pressure fluids and other used pipes. Its representative material is Q235A grade steel.

GB / T14291-1992 (Welding steel pipe for mine fluid transportation). Mainly used for straight seam welded steel pipes for mine pressure, drainage, shaft gas discharge. Its representative material is Q235A, B grade steel.

GB / T14980-1994 (large-diameter welded steel pipe for low-pressure fluid transportation). It is mainly used to transport low-pressure fluids such as water, sewage, gas, air, heating steam and other uses. Its representative material is Q235A grade steel.