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Practical Knowledge About Tubing

The classification of the pipe

1, according to the production method classification

(1) seamless pipe – hot-rolled pipe, cold-rolled pipe, cold-drawn pipe, extruded pipe, top pipe

(2) Welded pipe

(a) according to the process – electric arc welding pipe, resistance welding pipe (high frequency, low frequency), gas welding pipe, furnace welding pipe

(b) according to the welding seam – straight seam welded pipe, spiral welded pipe

2, according to the shape of the section classification

(1) simple section of steel pipe – round steel pipe, square steel pipe, oval steel pipe, triangular steel pipe, hexagonal steel pipe, rhombus-shaped steel pipe, octagonal steel pipe, semi-circular steel circle, other

(2) complex section steel pipe – unequal hexagonal steel pipe, five plum-shaped steel pipe, double convex steel pipe, double concave steel pipe, melon-shaped steel pipe, conical steel pipe, corrugated steel pipe, case steel pipe, other

3,according to the classification of wall thickness – thin-walled steel pipe, thick-walled steel pipe

4, according to the classification of use – pipe, steel pipe for thermal equipment, steel pipe for mechanical industry, oil, geological drilling steel pipe, container steel pipe, chemical industry steel pipe, special-purpose steel pipe, other

Classification by application


seamless steel pipe


 A seamless steel pipe is a long strip of steel with a hollow cross-section and no seams around it. Steel pipe has a hollow cross-section and is used in large quantities as a pipeline for transporting fluids, such as oil, natural gas, gas, water, and certain solid materials. Compared with solid steel such as round steel, steel pipe is lighter in weight when the bending and torsional strength is the same, is economic cross-sectional steel, widely used in the manufacture of structural and mechanical parts, such as oil drilling rods, automobile drive shafts, bicycle frames and steel scaffolding used in construction. Steel pipe manufacturing ring parts, can improve material utilization, simplify the manufacturing process, saving materials and processing hours, such as rolling bearing rings, jack sets, etc., has been widely used to manufacture steel pipe. Steel pipe is also a variety of conventional weapons indispensable materials, gun barrels, barrels, etc. to steel pipe to manufacture. Steel tubes can be divided into round tubes and shaped tubes according to the different shapes of the cross-sectional area. As the circular area is the largest under the condition of equal circumference, more fluid can be conveyed with circular tubes. In addition, the circular cross-section in the internal or external radial pressure, the force is more uniform, therefore, the vast majority of steel pipe is a circular pipe. However, the round tube also has certain limitations, such as in the plane bending conditions, the round tube is not as strong as the square, rectangular tube bending strength, some agricultural machinery skeleton, steel and wood furniture, etc. are commonly used square, rectangular tube. According to different uses also a need to have other cross-sectional shapes of shaped steel pipe.

1. seamless steel pipe for structure (GB/T8162-1999): seamless steel pipe for general structure and mechanical structure. 

2. Seamless steel pipe for fluid transportation (GB/T8163-1999): general seamless steel pipe for the transportation of water, oil, gas and other fluids

3. Seamless steel pipe for low and medium pressure boiler (GB3087-1999): It is a high quality carbon structural steel hot-rolled and cold-drawn (rolled) seamless steel pipe used for the manufacture of superheated steam tubes, boiling water tubes for low and medium pressure boilers of various structures and superheated steam tubes, large smoke tubes, small smoke tubes and arch brick tubes for locomotive boilers.

4. Seamless steel tubes for high-pressure boilers (GB5310-1995): seamless steel tubes of high-quality carbon steel, alloy steel and stainless heat-resistant steel for the heating surface of water tube boilers with high pressure and above.

5. High-pressure seamless steel pipe for fertilizer equipment (GB6479-86): It is a seamless steel pipe of high-quality carbon structural steel and alloy steel for chemical equipment and pipelines with working temperature of -40~400 ℃ and working pressure of 10~30 Ma.

6. Seamless steel pipe for petroleum cracking (GB9948-88): Seamless steel pipe for furnace tube, heat exchanger and pipeline of petroleum refinery.

7. Steel pipe for geological drilling (YB235-70): It is a steel pipe used for core drilling in the geological department and can be divided into drill pipe, drill collar, core pipe, casing and sediment pipe according to the purpose.

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

9. Oil drilling pipe (YB528-65): Seamless steel pipe with thickened inside or outside ends for oil drilling. The steel pipe is divided into two types: wire and non-wire, and the wire pipe is coupled with a joint, while the non-wire pipe is coupled with a tool joint by butt welding.

10. seamless carbon steel pipe for ships (GB5213-85): It is a seamless carbon steel pipe for the manufacture of ship I pressure resistant pipe system, II pressure resistant pipe system, boiler and superheater. The working temperature of carbon steel seamless steel pipe wall does not exceed 450 ℃, and the working temperature of alloy steel seamless steel pipe wall exceeds 450 ℃.

11. Seamless steel pipe for automobile half-shaft casing (GB3088-82): It is a high quality carbon structural steel and alloy structural steel hot-rolled seamless steel pipe for manufacturing automobile half-shaft casing and axle casing axle pipe for drive axle.

12 diesel engine high-pressure oil pipe (GB3093-86): is the manufacture of diesel injection system high-pressure seamless cold-drawn steel pipe.

13 precision bore seamless steel pipe for hydraulic and pneumatic cylinder barrels (GB8713-88): is the manufacture of hydraulic and pneumatic cylinder barrels with precision bore size of cold-drawn or cold-rolled precision seamless steel pipe.

14. Cold-drawn or cold-rolled precision seamless steel pipe (GB3639-83): cold-drawn or cold-rolled precision seamless steel pipe with high dimensional accuracy and good surface finish for mechanical structures and hydraulic equipment. The selection of precision seamless steel pipe manufacturing mechanical structures or hydraulic equipment, etc., can greatly save machining hours, improve material utilization, while helping to improve product quality.

15. Structural stainless steel seamless steel pipe (GB/T14975-1994): It is widely used in chemical, petroleum, light textile, medical, food, machinery and other

It is a seamless steel pipe made of stainless steel for chemical, petroleum, light textile, medical, food, machinery and other industries, which is made of corrosion-resistant pipes and structural parts and components, and is hot rolled (extruded, expanded) and cold drawn (rolled).

16.Stainless steel seamless steel pipe for fluid transportation (GB/T14976-1994): It is hot rolled (extruded, expanded) and cold drawn (rolled) seamless steel pipe made of stainless steel for fluid transportation.

17.Shaped seamless steel pipe is a general term for seamless steel pipe with a cross-sectional shape other than a round pipe. According to the different sizes of steel pipe cross-sectional shape, it can be divided into equal wall thickness shaped seamless steel pipe (code D), unequal wall thickness shaped seamless steel pipe (code BD), variable diameter shaped seamless steel pipe (code BJ). Shaped seamless steel tubes are widely used for various structural parts, tools and mechanical parts. Compared with round tubes, shaped tubes generally have a larger moment of inertia and cross-sectional modulus, and have greater bending and torsional resistance, which can greatly reduce the weight of the structure and save steel.


Zhishang Steel Co., Ltd

ABOUT USOverviewThe company mainly deals in color-coated, galvanized, stainless steel pipes, stainless steel coils, stainless steel plates of various materials; hot-rolled series of rebar, medium and heavy plates, coils, I-beams, angle steels, channel steels, H-beams and other steel products and deep processing Service. (The company’s annual invent···

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