Seamless Steel Pipe

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Seamless Steel Pipe

The seamless steel pipe usually has a specification of 8-1240×1-200 mm, which represents outer diameter × wall thickness (unit: mm). According to different production methods, it can be divided into hot-rolled one and cold-rolled (drawn) one. In general, the hot-rolled type is divided into general steel pipe, low and medium pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, petroleum cracking tube, geological steel pipe, and so on. The cold-rolled (drawn) seamless steel pipe is also applicable to the above classification and includes extra precision steel tube, carbon thin-wall steel tube, alloy thin-wall steel pipe, stainless steel thin-wall tube, shaped steel tube, etc.

The hot-rolled seamless pipe generally comes with an outer diameter of over 32mm and wall thickness of 2.5-75mm. In addition, the cold-rolled one achieves an outer diameter of 6mm and wall thickness of 0.25mm, while the outer diameter of the thin-wall tube can reach 5mm with the wall thickness less than 0.25mm. This indicates that the cold-rolled one has a higher dimensional accuracy than the hot-rolled one. However, the hot-rolled piece enjoys smaller deformation resistance and larger deformation amount, due to the high rolling temperature. In the piping and plumbing system, hot-rolled tube is often used with the pipe diameter more than 57mm, while the cold-drawn (rolled) pipe is commonly used with the diameter less than 57mm.

Generally, the seamless steel pipe is made of 10 #, 20 #, 30 #, 35 #, 45 #, and other high quality carbon structural steel, or 16Mn, 5MnV, and other low-alloy structural steel, or 40Cr, 30CrMnSi, 45Mn2, 40MnB, and other alloy structural steel. The one made of 10 #, 20 # and other low-carbon steel is commonly used for conveyance of fluids. The one made of 40Cr, 45 #, and other medium carbon steel is usually used for the manufacture of mechanical parts of automobiles, tractors, etc. All the pipes must go through the flattening test to ensure enough strength. The hot-rolled steel pipe can be delivered directly in the state of hot rolling with or without special heat treatment, while the final cold-rolled pipe is processed with heat treatment.

Seamless Steel Pipe Seamless Steel Pipe

The seamless steel tube with hollow cross-section is widely used to convey fluids such as oil, gas, water and some solid materials. Compared with round steel and other solid steel, the steel pipe is lighter while maintaining the same bending and torsion resistance. Hence, this economical product is broadly applied in the manufacture of structural parts and mechanical parts, such as oil drill pipe, automobile transmission shaft, bicycle frame, and steel scaffolding used on construction sites. When used to manufacture annular parts like rolling bearing ring and lifting jack, it can improve the material utilization, simplify the manufacturing process, thus saving material and machining time. What's more, it is also an indispensable material in the manufacture of various conventional weapons, such as gun and cannon.

According to different cross-sectional area shapes, the steel pipe can be divided into round pipe and shaped pipe. As a circle gains the largest area among other shapes with the same perimeter, so the round pipe can transport more fluids than the pipe of other shapes. In addition, the ring cross section can withstand internal or external radial pressure force more uniformly, so the vast majority of steel pipe is circular in cross section. However, the round tube has some limitations. For example, under the condition of plane bending, the circular tube is not as good as square, rectangular tube in bending strength. Hence, the square or rectangular tube is frequently used in the manufacture of farm machinery skeleton, steel and wood furniture. Furthermore, other cross-section shapes of the pipe are also available in accordance with different uses.

Pipe Types with Different Applications
1. Structural seamless steel pipe (GB/T8162-2008) is used for general structure and mechanical structure.
2. Fluid seamless steel pipe (GB/T8163-2008) is used for general conveyance of water, oil, gas and other fluids.
3. Low and medium pressure boiler seamless steel pipe (GB3087-2008) is a hot rolled or cold rolled (drawn) pipe made of high-quality carbon structural steel. It can be used in the manufacture of a variety of superheated steam pipes and hot boiling water pipes for low and medium pressure boiler, as well as superheated steam tubes and arch tubes for locomotive boiler.
4. High pressure boiler seamless pipe (GB5310-2008) is a high-quality carbon steel, alloy steel and heat-resistant stainless steel pipe used in the manufacture of heating water tube for high pressure boiler.
5. Chemical fertilizer seamless pipe (GB6479-2000) is a high quality carbon structural steel and alloy steel pipe applicable to the chemical equipment and pipeline with the working temperature of -40 ~ 400 ℃ and working pressure of 10 ~ 30Ma.
6. Petroleum seamless steel pipe (GB9948-2006) is applicable to petroleum refinery furnace tubes, heat exchangers and pipeline.
7. Geological drilling steel pipe (YB235-70) is provided for the geological department to conduct core drilling. It can be divided into drill pipe, drill collar, core pipe, casing and precipitation tube, etc. according to different uses.
8. Diamond core drilling seamless steel pipe (GB3423-82) is applicable to drill pipe, core rod, casing used for diamond core drilling.
9. Oil drill pipe (YB528-65) is an internal or external upset pipe used in oil drilling. It has sub-threading and threading two types, with the threading pipe connected with joints and non-threading pipe welded and linked with tool joints.
10. Ship carbon steel seamless steel pipe (GB5213-85) is used for ship class I and II pressure piping, boiler, and superheater, with the temperature for pipe wall not exceeding 450 º C.
11. Automobile axle casing seamless steel pipe (GB3088-82) is a hot-rolled pipe which is made of quality carbon structural steel and alloy structural steel. It is suitable for the manufacture of automobile axle tube.
12. Diesel engine high pressure oil pipe (GB3093-2002) is a cold-drawn one used for high-pressure tubing in diesel injection system.
13. Hydraulic and pneumatic cylinder seamless steel pipe with precision internal diameter (GB8713-88) is manufactured with cold drawing or cold rolling.
14. Cold drawn or cold rolled precision seamless steel pipe (GB3639-2000) with high dimensional accuracy and good surface finish can greatly reduce the mechanical processing time, improve material utilization, and help to improve the product quality when used in the manufacture of mechanical structure, hydraulic equipment, etc.
15. Structural stainless steel seamless pipe (GB/T14975-2002) is a hot-rolled (extrusion, expansion) and cold drawn (rolled) tube. It is widely used to produce anti corrosion pipeline, structural parts, and components in chemical, petroleum, textile, medical, food, machinery and other industries.
16. Fluid transportation stainless steel seamless pipe (GB/T14976-2002) is hot rolled (extrusion, expansion) or cold drawn (rolled) for conveying fluids.
17. Shaped seamless steel pipe is the general term for pipes of other cross section shapes in addition to the circular tube. According to different shapes and sizes of cross-section, the pipe can be further divided into equal wall thickness type (code D), unequal wall thickness type (code BD), and variable diameter type (code BJ). It is widely used in various structural parts, tools and mechanical parts. Compared with the round tube, the shaped pipe generally has a greater moment of inertia and cross-section modulus and better bending and torsion resistance, so as to greatly reduce structural weight and save steel consumption.
18. Low-temperature seamless steel pipe (GB/T18984-2003) applies to -45 º C ~ -195 º C cryogenic pressure vessel piping and low temperature heat exchanger tube.

1. Structural Seamless Steel Pipe
National standard: GB/T8162-2008
Material: 10, 20, 35, 45, 40Mn2, 45Mn2, 27SiMn, 20Cr, 40Cr, 20CrMo, 35CrMo, 38CrMoA1, 50CrV, 30CrMnSi ASTM A500-98
International standard: ASTM A501-98 ASTN A519-98 JIS G3441-1994

2. Fluid Conveyance Seamless Steel Pipe 
National standard: GB/T8163-2008
Material: 10#, 20#, Q295, Q345
International standard: ASTM A53-98 ASTM A192 ASME S192 JIS G3452-1998 FIS G3454-1998 DIN 1629-1984

3. Oil Well Pipe, Coupling Feed Tube, Line Pipe
National standard: API SPEC 5CT APE SPEC 5L
Material: J55,N80 A,B,X42 
International standard: API 

4. High Pressure Boiler Seamless Pipe
National standard: GB5310-2008
Material: 20G, 20MnG, 25MnG, 15MoG, 20MoG, 12Cr1MoVG, 15CrMoVG, 12Cr2MoG, 12Cr2MoWVTiB, 12Cr3MoVSiTiB
International standard: ASTM A106-96a, ASTM A210C, ATSM A213-95a, JIS G3461-1988, JIS G3462-1998, DIN 17175-1979, BS3059: Part 2: 1990

5. Low and Medium Pressure Boiler Seamless Steel Pipe
National standard: GB3087-2008
Material: 10#, 20 #
International standard: ASTM A179, ASTM A192, ASTM SA179,SA192, BS3059 

6. Chemical Fertilizer High Pressure Seamless Steel Pipe
National standard: GB6479-2000
Material: 10#, 20G, Q345, Q390, 10MoVNb, 12CrMo, 15CrMo, 12Cr2Mo
International standard: ISO 9329-2-1997, ASTM A161-94

7. Petroleum Cracking Seamless Steel Pipe
National standard: GB9948-2006
Material: 10#, 20#, 12CrMo, 15CrMo, 1Cr2Mo, 1Cr5Mo
International standard: JIS G3441-1988

8. Automobile Axle Casing Seamless Steel Pipe
National standard: Q/OHAD001-1997 YB/T5035-1998
Material: 45Mn2, 45#, 25MnCr
International standard: DIN 1629-1984

9. Hydraulic Prop Hot Rolled Seamless Steel Pipe
Standard: Q/OHAD010-2007 GB/T17398-2007
Material: 27SiMn

10. Ship Carbon, Carbon-Manganese Steel Seamless Pipe
Standard: GB/T5312-1999
Material: Q320, Q360, Q410, Q460, Q490
International standard: DIN 2391-1994

11. Cold Drawn Precision Seamless Steel Pipe
Standard: GB/T3639-2000 GB/T8713-88
Material: 10#, 20#, 35#, 45#, 30CrMo

12. Geological Drilling Seamless Steel Pipe
Standard: YB/T5052-93 YB235-70
Material: DZ40, DZ50

13. Cannon Seamless Steel Pipe
Standard: YBn1-86
Material: 40Mn2, D60

14. Mandril Seamless Steel Pipe
Standard: Q/OHAD003-94
Material: 1CrMo

15. Bearing Seamless Steel Pipe
Standard: YB/Z12-77YJZ84
Material: GCr15

16. Ribbed Rebar Connecting Sleeve Seamless Steel Pipe
Standard: Q/OHAD011-1997a
Material: 10#, 20#

17. Gas Cylinder Seamless Steel Pipe
Material: 34Mn2V, 30CrMo, 35CrMo, 45#

The seamless steel pipe is manufactured conforming to ISO9001 international quality management system, ISO14001 environmental management system and ISO18001 occupational health safety control system. Our Carbon Steel Pipes, alloy steel pipes and stainless steel pipes can be provided with various specifications and materials. In collaboration with Tianjin Pipe Group Corp, Shanghai Baoshan Steel Corporation, Chengdu Steel Factory, Jiangsu Chengde Steel Factory, Baotou Steel (Group) Corporation, Anshan Iron and Steel Corp, and steel pipe manufactures in US, Britain, Japan, Germany, Italy, etc. They are widely used in pipeline projects in petroleum, chemical, natural gas, nuclear power, thermoelectricity, metallurgy, thermal pipe network, shipbuilding, papermaking, construction, etc.

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