I. Classification of Pipes
1. Classified by production methods
(1) Seamless pipes - Hot-rolled pipes, Cold-rolled pipes, Cold-drawn pipes, Extruded pipes, Pipe jacking pipes
(2) Welded pipe
(a) Classified by process - Arc welding pipes, Resistance welding pipes (high frequency, low frequency), Gas welding pipes, Furnace welding pipes
(b) Classified by weld type - straight seam welded pipe, spiral welded pipe
II. Seamless Steel Pipes
The structure is made of seamless steel pipes (GB/T8162-1999), which are used for general structures and mechanical structures.
2. Seamless steel pipes for fluid transportation (GB/T8163-1999) are general seamless steel pipes used for transporting fluids such as water, oil, and gas.
3. Seamless steel pipes for low and medium pressure boilers (GB3087-1999) are high-quality carbon structural steel hot-rolled and cold-drawn (rolled) seamless pipes used for manufacturing various structural low and medium pressure boiler superheater steam pipes, boiling water pipes, and superheater steam pipes for locomotives, as well as large and small smoke tubes and arch brick tubes.
4. Seamless steel pipes for high-pressure boilers (GB5310-1995) are high-quality carbon steel, alloy steel and stainless heat-resistant steel seamless pipes used for manufacturing the heating surfaces of water-tube boilers with high pressure and above.
5. High-pressure seamless steel pipes for fertilizer equipment (GB6479-86) are high-quality carbon structural steel and alloy steel seamless pipes suitable for chemical equipment and pipelines operating at a temperature range of -40 to 400 ℃ and a working pressure of 10 to 30 Ma.
6. Seamless steel pipes for petroleum cracking (GB9948-88) are suitable for use as furnace tubes, heat exchangers and pipelines in petroleum refineries.
7. Geological drilling steel pipes (YB235-70) are steel pipes used by geological departments for core drilling. According to their purposes, they can be classified as drill rods, drill collars, core tubes, casings, and sediment tubes, etc.
8. Seamless steel pipes for diamond core drilling (GB3423-82) are seamless steel pipes used for drill rods, core rods and casings in diamond core drilling operations.
9. Petroleum drilling pipe (YB528-65) is a type of seamless steel pipe with internal or external thickening at both ends for use in petroleum drilling. The steel pipes are available in both threaded and non-threaded versions. The threaded pipes are connected using couplings, while the non-threaded pipes are joined using the fusion welding method and tools.
10. The carbon steel seamless pipes used for ships (as per GB5213-85) are carbon steel seamless pipes used for manufacturing Class I pressure-bearing piping systems, Class II pressure-bearing piping systems, boilers and superheaters of ships. The working temperature of the pipe walls of carbon steel seamless pipes does not exceed 450 ℃, while that of alloy steel seamless pipes exceeds 450 ℃.
11. The semi-axle bushing tubes are made of seamless steel pipes (GB3088-82), which are high-quality carbon structural steel and alloy structural steel hot-rolled seamless steel pipes used for manufacturing the semi-axle bushings and the axle tubes of the drive axle housing of automobiles.
12. The high-pressure fuel pipe for diesel engines (GB3093-86) is a cold-drawn seamless steel pipe used for manufacturing the high-pressure pipes of diesel engine injection systems.
13. The precision inner diameter seamless steel tubes (GB8713-88) used for hydraulic and pneumatic cylinder barrels are cold-drawn or cold-rolled precision seamless steel tubes with precise inner diameter dimensions, which are used for manufacturing hydraulic and pneumatic cylinder barrels.
14. Cold-drawn or cold-rolled precision seamless steel pipes (GB3639-83) are cold-drawn or cold-rolled precision seamless steel pipes with high dimensional accuracy and good surface finish, which are used in mechanical structures and hydraulic equipment. Choosing to manufacture mechanical structures or hydraulic equipment with precision seamless steel pipes can significantly reduce machining time, increase material utilization, and at the same time, help improve product quality.
15. The structure is made of seamless stainless steel pipes (as per GB/T14975-1994) which are widely used in various industries such as chemical, petroleum, textile, medical, food, and machinery for corrosion-resistant pipelines, structural components, and parts. They are made of hot-rolled (extruded, expanded) and cold-drawn (rolled) seamless stainless steel pipes.
16. Stainless steel seamless pipes for fluid transportation (GB/T14976-1994) are hot-rolled (extruded, expanded) and cold-drawn (rolled) seamless pipes made of stainless steel and used for transporting fluids.
17. Irregular Seamless Steel Pipes refer to all seamless steel pipes with cross-sectional shapes other than circular ones. Depending on the different dimensions of the pipe's cross-section, they can be classified into equal-wall-thickness irregular seamless steel pipes (denoted as D), unequal-wall-thickness irregular seamless steel pipes (denoted as BD), and variable-diameter irregular seamless steel pipes (denoted as BJ). Irregular seamless steel pipes are widely used in various structural components, tools, and mechanical parts. Compared to circular pipes, irregular pipes generally have larger moments of inertia and section moduli, greater bending and torsion resistance, and can significantly reduce structural weight and save steel.
