Overview of seamless steel pipes

Seamless steel pipes have a hollow cross-section and are widely used as pipelines for transporting fluids, such as oil, natural gas, coal gas, water, and certain solid materials. Compared with solid steel such as round steel, steel pipes are lighter in weight when their bending and torsional strength is the same. They are an economical cross-sectional steel material widely used in the manufacture of structural and mechanical parts, such as oil drill rods, automotive transmission shafts, bicycle frames, and steel scaffolding used in construction. Steel pipes are used to manufacture circular parts, which can improve material utilization, simplify manufacturing processes, save materials and processing time. For example, rolling bearing rings, jack sleeves, etc., steel pipes are widely used in manufacturing. Steel pipes are still an indispensable material for various conventional weapons, such as gun barrels and cannon barrels, which require steel pipes for manufacturing. Steel pipes can be divided into circular pipes and special-shaped pipes according to their cross-sectional area and shape. Due to the fact that the circular area is the largest under the condition of equal circumference, a circular tube can transport more fluid. In addition, when subjected to internal or external radial pressure, the circular cross-section is subjected to more uniform force, therefore, the vast majority of steel pipes are circular.

However, circular pipes also have certain limitations. For example, under the condition of planar bending, circular pipes have lower bending strength than square and rectangular pipes. Some agricultural machinery skeletons, steel and wood furniture, etc. commonly use square and rectangular pipes. Different cross-sectional shapes of special-shaped steel pipes are required for different purposes.

Seamless steel pipe execution standard

1. Seamless pipes for structures (GB/T8162-2008) are seamless steel pipes used for general and mechanical structures.

2. Seamless steel pipes for fluid transportation (GB/T8163-2008) 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 (GB3087-2008) are high-quality carbon structural steel hot-rolled and cold drawn (rolled) seamless steel pipes used to manufacture various structures of superheated steam pipes, boiling water pipes, and superheated steam pipes and arch brick pipes for locomotive boilers.

4. Seamless steel pipes for high-pressure boilers (GB5310-2008) are high-quality carbon steel, alloy steel, and stainless heat-resistant seamless steel pipes used for the heating surface of water tube boilers with high pressure and above.

5. High pressure seamless steel pipes for fertilizer equipment (GB6479-2000) are high-quality carbon structural steel and alloy steel seamless steel pipes suitable for chemical equipment and pipelines with working temperatures of -40~400 ℃ and working pressures of 10~30Ma.

6. Seamless steel pipes for petroleum cracking (GB9948-2006) are suitable for furnace tubes, heat exchangers, and pipelines in petroleum refineries.

7. Geological drilling steel pipe (YB235-70) is a steel pipe used by geological departments for core drilling. It can be divided into drill rods, drill collars, core pipes, casings, and sedimentation pipes according to its purpose.

8. Seamless steel pipe for diamond core drilling (GB3423-82) is a seamless steel pipe used for drill rods, core rods, and casing in diamond core drilling.

9. Oil drilling pipe (YB528-65) is a seamless steel pipe used for oil drilling with inner or outer thickening at both ends. Steel pipes are divided into two types: threaded and non threaded. Threaded pipes are connected with joints, while non threaded pipes are connected with tool joints by butt welding.

10. Carbon steel seamless steel pipes for ships (GB5213-85) are carbon steel seamless steel pipes used for manufacturing Class I pressure resistant piping systems, Class II pressure resistant piping systems, boilers, and superheaters for ships. The working temperature of carbon steel seamless steel pipe wall shall not exceed 450 ℃, and the working temperature of alloy steel seamless steel pipe wall shall exceed 450 ℃.

11. Seamless steel pipes for automotive half shaft sleeves (GB3088-82) are high-quality carbon structural steel and alloy structural steel hot-rolled seamless steel pipes used for manufacturing automotive half shaft sleeves and drive axle housing shaft sleeves.

12. High pressure fuel pipes for diesel engines (GB3093-2002) are cold drawn seamless steel pipes used to manufacture high-pressure pipes for diesel injection systems.

13. Precision inner diameter seamless steel pipe for hydraulic and pneumatic cylinder tubes (GB8713-88) is a cold drawn or cold-rolled precision seamless steel pipe with precise inner diameter dimensions used for manufacturing hydraulic and pneumatic cylinder tubes.

14. Cold drawn or cold-rolled precision seamless steel pipes (GB3639-2000) are used for mechanical structures and hydraulic equipment with high dimensional accuracy and good surface smoothness. Choosing precision seamless steel pipes to manufacture mechanical structures or hydraulic equipment can greatly save machining hours, improve material utilization, and also contribute to improving product quality.

15. Stainless steel seamless steel pipes for structural use (GB/T14975-2002) are hot-rolled (extruded, expanded) and cold drawn (rolled) seamless steel pipes made of stainless steel, widely used in industries such as chemical, petroleum, textile, medical, food, and machinery for corrosion-resistant pipelines, structural components, and parts.

16. Seamless stainless steel pipes for fluid transportation (GB/T14976-2002) are hot-rolled (extruded, expanded) and cold drawn (rolled) seamless steel pipes made of stainless steel used for fluid transportation.

17. Irregular seamless steel pipe is a general term for seamless steel pipes with cross-sectional shapes other than round pipes. According to the different cross-sectional shapes and sizes of steel pipes, they can be divided into equal wall thickness irregular seamless steel pipes (code D), unequal wall thickness irregular seamless steel pipes (code BD), and variable diameter irregular seamless steel pipes (code BJ). Irregular seamless steel pipes are widely used in various structural components, tools, and mechanical parts. Compared with circular pipes, special-shaped pipes generally have larger moments of inertia and section moduli, and have greater bending and torsional resistance, which can greatly reduce structural weight and save steel.

18. Seamless steel pipes for low-temperature pipelines (GB/T18984-2003) are suitable for low-temperature pressure vessel pipelines and low-temperature heat exchanger pipelines ranging from -45 ℃ to -195 ℃.

formula

The calculation formula for the weight per meter of seamless steel pipe is: 0.02466 * wall thickness * (outer diameter wall thickness)

The calculation formula for the weight per meter of stainless steel pipe is: 0.02491 * wall thickness * (outer diameter wall thickness)

The calculation formula for the weight per meter of alloy tube is 0.02483 * wall thickness (outer diameter wall thickness)