Structural pipes, this standard is applicable to seamless steel pipes for general structures and mechanical structures, while the fluid seamless steel pipe standard is applicable to general seamless steel pipes for conveying fluids. The main difference between it and structural seamless steel pipes is that fluid seamless steel pipes are subjected to hydraulic testing or ultrasonic, eddy current, and magnetic leakage testing one by one. Therefore, in the standard selection of pressure pipeline steel pipes, it is not advisable to use fluid seamless steel pipes. Seamless steel pipes are represented by outer diameter, wall thickness, and thick walled seamless steel pipes, which are mainly used for various purposes such as mechanical processing, coal mining, hydraulic steel, etc. The materials of thick walled seamless steel pipes are divided into 10 #, 20 #, 35 #, 45 # 16Mn, 27SiMn, 12Cr1MoV, 10CrMo910, 15CrMo, 35CrMo, etc. Classification of thick walled seamless steel pipes - hot-rolled thick walled seamless steel pipes, cold-rolled thick walled seamless steel pipes, cold drawn thick walled seamless steel pipes, extruded thick walled seamless steel pipes, and top pipes. Stainless steel seamless steel pipes for structural purposes (GB/T14975-1994) are hot-rolled (extruded, expanded) and cold-drawn (rolled) seamless steel pipes made of stainless steel, which are widely used in industries such as chemical, petroleum, light textile, medical, food, machinery, and other corrosion-resistant pipelines and structural components.

Application of seamless steel pipes of various materials

Seamless steel pipes are divided into several varieties due to their different uses:

GB/T8162-1999 (Seamless Steel Pipes for Structural Purposes). Mainly used for general structures and mechanical structures. Its representative material (grade): carbon steel 20, 45 steel; Alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo, etc.

GB/T8163-1999 (Seamless steel pipes for fluid transportation). Mainly used for conveying fluid pipelines in engineering and large equipment. The representative materials (grades) are 20, Q345, etc.

GB3087-1999 (Seamless steel pipes for low and medium pressure boilers). Mainly used in pipelines for conveying low and medium pressure fluids in industrial boilers and domestic boilers. The representative materials are grade 10 and 20 steel.

GB5310-1995 (Seamless steel pipes for high-pressure boilers). Mainly used for high-temperature and high-pressure conveying fluid headers and pipelines in power plants and nuclear power plant boilers. The representative materials are 20G, 12Cr1MoVG, 15CrMoG, etc.

GB5312-1999 (Seamless Carbon and Carbon Manganese Steel Pipes for Ships). Mainly used for Class I and II pressure resistant pipes for ship boilers and superheaters. The representative materials are 360, 410, 460 steel grades, etc.

GB1479-2000 (Seamless steel pipes for high-pressure fertilizer equipment). Mainly used for conveying high-temperature and high-pressure fluid pipelines on fertilizer equipment. The representative materials are 20, 16Mn, 12CrMo, 12Cr2Mo, etc.

GB9948-1988 (Seamless steel pipes for petroleum cracking). Mainly used for boilers, heat exchangers, and fluid pipelines in oil refineries. Its representative materials are 20, 12CrMo, 1Cr5Mo, 1Cr19Ni11Nb, etc.

GB18248-2000 (Seamless steel pipes for gas cylinders). Mainly used for making various gas and hydraulic cylinders. Its representative materials are 37Mn, 34Mn2V, 35CrMo, etc.

GB/T17396-1998 (Hot rolled seamless steel pipes for hydraulic supports). Mainly used for making hydraulic supports, cylinders, and columns in coal mines, as well as other hydraulic cylinders and columns. Its representative materials are 20, 45, 27SiMn, etc.

GB3093-1986 (High pressure seamless steel pipes for diesel engines). Mainly used for high-pressure fuel pipes in diesel engine injection systems. The steel pipe is generally cold drawn, with a representative material of 20A.

GB/T3639-1983 (Cold drawn or cold-rolled precision seamless steel pipes). Mainly used for steel pipes with high dimensional accuracy and good surface smoothness in mechanical structures and carbon compression equipment. It represents materials such as 20 and 45 steel.

GB/T3094-1986 (Cold drawn seamless steel pipes and special-shaped steel pipes). Mainly used for making various structural components and parts, its materials are high-quality carbon structural steel and low alloy structural steel.

GB/T8713-1988 (Precision inner diameter seamless steel pipes for hydraulic and pneumatic cylinders). Mainly used for producing seamless steel pipes with precision inner diameter dimensions for hydraulic and pneumatic cylinders. Its representative materials are 20, 45 steel, etc.

GB13296-1991 (Stainless steel seamless steel pipes for boilers and heat exchangers). Mainly used in boilers, superheaters, heat exchangers, condensers, catalytic tubes, etc. in chemical enterprises. Steel pipes that are resistant to high temperature, high pressure, and corrosion. Its representative materials are 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc.

GB/T14975-1994 (Seamless Stainless Steel Pipes for Structural Purposes). Mainly used for general structures (hotel, restaurant decoration) and mechanical structures in chemical enterprises, it is a steel pipe that is resistant to atmospheric and acid corrosion and has a certain strength. Its representative materials are 0-3Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc.

GB/T14976-1994 (Stainless steel seamless steel pipes for fluid transportation). Mainly used for transporting corrosive media in pipelines. The representative materials are 0Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr17Ni12Mo2, 0Cr18Ni12Mo2Ti, etc.

YB/T5035-1993 (Seamless steel pipes for automotive half shaft sleeves). Mainly used for producing high-quality carbon structural steel and alloy structural steel hot-rolled seamless steel pipes for automotive half axle sleeves and drive axle axle housing axle tubes. Its representative materials are 45, 45Mn2, 40Cr, 20CrNi3A, etc.