Common materials of welded pipes are: Q235A, Q235C, Q235B, 16Mn, 20#, Q345, L245, L290, X42, X46, X60, X80, 0Cr13, 1Cr17, 00cr19ni11, 1Cr18Ni9, 0cr18ni11nb, etc.The blank used for welded steel pipe is steel plate or strip steel. Due to different welding processes, it is divided into furnace welded pipe, electric welding (resistance welding) pipe and automatic arc welded pipe. Because of their different welding forms, they are divided into straight seam welded pipe and spiral welded pipe. Because of its end shape, it is divided into circular 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 / t3091-2008 (welded steel pipe for low pressure fluid transportation): it is mainly used to transport water, gas, air, oil, heating hot water or steam and other general low pressure fluids and pipes for other purposes. Its representative material is Q235 grade a steel. GB / t14291-2006 (welded steel pipe for mining fluid transportation): it is mainly used for straight seam welded steel pipe for mine air pressure, drainage and shaft gas drainage. Its representative material is grade Q235A and B steel. GB / t12770-2002 (stainless steel welded steel pipe for mechanical structure): mainly used for machinery, automobile, bicycle, furniture, hotel and restaurant decoration and other mechanical parts and structural parts. The representative materials are 0Cr13, 1Cr17, 00cr19ni11, 1Cr18Ni9, 0cr18ni11nb, etc. GB / t12771-1991 (stainless steel welded steel pipe for fluid transportation): it is mainly used to transport low-pressure corrosive media. The representative materials are 0Cr13, 0Cr19Ni9, 00cr19ni11, 00Cr17, 0cr18ni11nb, 0017cr17ni14mo2, etc. In addition, welded stainless steel pipes for decoration (GB / T 18705-2002), welded stainless steel pipes for architectural decoration (JG / T 3030-1995), and welded steel pipes for heat exchangers (yb4103-2000). Longitudinal welded pipe has the advantages of simple production process, high production efficiency, low cost and rapid development. The strength of spiral welded pipe is generally higher than that of straight welded pipe. It can produce welded pipe with larger pipe diameter with narrow blank, and welded pipe with different pipe diameter with blank of the same width. However, compared with the straight seam pipe with the same length, the weld length increases by 30 ~ 100%, and the production speed is low. Raw material uncoiling - leveling - end shearing and welding - looper - forming - Welding - internal and external weld bead removal - pre correction - induction heat treatment - sizing and straightening - eddy current testing - cutting - hydraulic inspection - Pickling - final inspection (strict control) - Packaging - shipment. The products are widely used in tap water engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation and urban construction. It is one of the 20 key products developed in China.

Water supply and drainage. For gas transmission: gas, steam and liquefied petroleum gas.As pile driving pipe and bridge; Pipes for wharf, road, building structure, etc.