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

GB / T3091-1993 (galvanized welded steel pipe for low-pressure fluid transportation). It is mainly used to transport water, gas, air, oil, and generally lower pressure fluids such as hot water or steam and other purposes.

GB / T3092-1993 (galvanized welded steel pipe for low-pressure fluid transportation). It is mainly used to transport water, gas, air, oil, and generally lower pressure fluids such as hot water or steam and other purposes.

GB / T14291-1992 (Mining fluid transport welded steel pipe). It is mainly used for straight seam welded steel pipes for mine pressure, drainage and shaft gas discharge. It represents the material Q235A, B grade steel. GB / T14980-1994 (Large diameter electric welded steel pipe for low pressure fluid transportation). Mainly used for conveying low-pressure fluids such as water, sewage, gas, air, heating steam and other purposes.

GB / T12770-1991 (stainless steel welded steel pipe for mechanical structure). Mainly used in machinery, automobiles, bicycles, furniture, hotel and restaurant decoration and other mechanical parts and structural parts.

GB / T12771-1991 (stainless steel welded steel pipe for fluid transportation). Mainly used to transport low-pressure corrosive media.