Welded steel pipes are made of steel plates or strips. Welded steel pipes are divided into furnace welded pipes, electric welded (resistance welded) pipes and automatic arc welded pipes due to their different materials and processes. They are divided into straight seam welded pipes and spiral welded pipes due to their different welding forms. They are divided into round welded pipes and special-shaped (square, flat, etc.) welded pipes due to their end shapes. They are divided into the following varieties according to their different uses:
GB/T3091 (galvanized welded steel pipes for low-pressure fluid transportation). Mainly used for conveying water, gas, air, oil, heating hot water or steam and other generally low-pressure fluids and other pipes. Its representative material is Q235A grade steel.
GB/T3092 (galvanized welded steel pipes for low-pressure fluid transportation). Mainly used for conveying water, gas, air, oil, heating hot water or steam and other generally low-pressure fluids and other pipes. Its representative material is: Q235A grade steel.
GB/T14291 (welded steel pipes for mining fluid transportation). Mainly used for straight seam welded steel pipes for mine air compression, drainage, and axial gas discharge. Its representative materials are Q235A and B grade steel.
GB/T14980 (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. Its representative material is Q235A grade steel.
GB/T12770 (Stainless steel welded steel pipe for mechanical structure). Mainly used for machinery, automobiles, bicycles, furniture, hotel and restaurant decoration and other mechanical parts and structural parts. Its representative materials are 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, etc. GB/T12771-1991 (Stainless steel welded steel pipe for fluid transportation). Mainly used for conveying low-pressure corrosive media. Representative materials are 0Cr13, 0Cr19Ni9, 00Cr19Ni11, 00Cr17, 0Cr18Ni11Nb, 0017Cr17Ni14Mo2, etc.
