Classification of Seamless Steel Pipes
Seamless steel tubes are divided into hot-rolled (extruded) seamless steel tubes and cold-drawn (rolled) seamless steel tubes due to their different manufacturing processes. Cold-drawn (rolled) pipes are divided into round pipes and special-shaped pipes. Seamless steel pipes are divided into the following varieties because of their different uses:
1.GB/T8162-2008 (seamless steel pipe for structure). Mainly used for general structure and mechanical structure. Its representative material (brand): carbon steel No.20 and No.45 steel; Alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo, etc.
2.GB/T8163-2008 (seamless steel pipe for conveying fluid). It is mainly use as a pipeline for conveying fluid in engineer and large-scale equipment. The representative materials (brands) are 20, Q345, etc.
3.GB3087-2008 (Seamless Steel Tube for Low and Medium Pressure Boilers). It is mainly used as a pipeline for conveying low and medium pressure fluids in industrial boilers and domestic boilers. The representative materials are 10 and 20 steel.
4.GB5310-2008 (Seamless Steel Tube for High Pressure Boiler). It is mainly used for high-temperature and high-pressure resistant fluid headers and pipelines on boilers of power stations and nuclear power plants. The representative materials are 20G, 12Cr1MoVG, 15CrMoG, etc.
5.GB5312-2009 (seamless steel tubes of carbon steel and carbon manganese steel for ships). It is mainly used for class I and II pressure pipes for marine boilers and superheaters, etc. The representative materials are steel grades 360, 410, 460, etc.
6.GB6479-2013 (Seamless Steel Pipe for High Pressure Fertilizer Equipment). It is mainly use for pipeline conveying high-temperature and high-pressure fluid on fertilize equipment. The representative materials are 20, 16Mn, 12CrMo, 12Cr2Mo, etc.
7.GB9948-2013 (Seamless Steel Pipe for Petroleum Cracking). It is mainly used for boilers, heat exchangers and fluid conveying pipelines in petroleum smelters. The representative materials are 20, 12CrMo, 1Cr5Mo, 1Cr19Ni11Nb, etc.
8.GB18248-2008 (seamless steel tube for gas cylinders). Mainly used for making all kinds of gas and hydraulic cylinders. The representative materials are 37Mn, 34Mn2V, 35CrMo, etc.
In addition, There are GB/T17396-1998 (hot rolled seamless steel pipe for hydraulic prop), GB3093-1986 (high pressure seamless steel pipe for diesel engine), GB/T3639-1983 (cold drawn or cold rolled precision seamless steel pipe), GB/T3094-1986 (cold drawn seamless steel pipe special-shaped steel pipe), GB/T 8711. GB13296-1991 (seamless stainless steel pipes for boilers and heat exchangers), GB/T14975-1994 (seamless stainless steel pipes for structures), GB/T14976-1994 (seamless stainless steel pipes for fluid transportation), GB/T5035-1993 (seamless steel pipes for automobile axle sleeves) and API spec 5CT (Casing and Tubing).
