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Classification of steel pipes

Nov. 06, 2019

The steel grades and specifications of steel pipe products are extremely diverse, and their performance requirements are also various. All of this should be differentiated as user requirements or working conditions change. Generally, steel pipe products are classified according to sectional shape, production method, pipe material, joining method, plating characteristics and use.

By section shape

Steel pipes can be divided into round steel pipes and special-shaped steel pipes according to the cross-sectional shape.

Shaped steel pipes refer to various non-circular sections of steel pipes. Among them are: square steel pipe, rectangular tube, elliptical tube and so on. Steel pipes are further divided into equal-section steel pipes and variable-section steel pipes according to the longitudinal section shape. The variable cross section (or variable cross section) steel pipe refers to a steel pipe which periodically or non-periodically changes in cross-sectional shape, inner and outer diameter, and wall thickness in the longitudinal direction of the pipe.

By production method

Steel pipes can be divided into two categories according to production methods: seamless steel pipes and welded steel pipes.

1. Seamless steel pipes can be divided into: hot-rolled seamless pipes, cold-drawn pipes, precision steel pipes, hot-expanded pipes, cold-spinning pipes and extruded pipes according to the production method.

2. Welded steel pipes are divided into furnace welded pipes, electric welded pipes and automatic arc welded pipes due to different welding processes. Because of their different welding forms, they are divided into straight welded pipes and spiral welded pipes, and their end shapes are divided into circular welded pipes. And shaped (square, flat, etc.) welded pipes.

By material

Steel pipes can be divided into: carbon pipes, alloy pipes, stainless steel pipes, etc. according to the pipe material.

Carbon pipes can be divided into ordinary carbon steel pipes and high-quality carbon structural pipes.

Alloy tubes can be further divided into: low alloy tubes, alloy structural tubes, high alloy tubes, high strength tubes. Bearing tubes, heat-resistant and acid-resistant stainless tubes, precision alloys tubes, and high-temperature alloy tubes.

Seamless Steel Pipe

Seamless Steel Pipe

Classified by connection

The steel pipe can be divided into the light pipe (the pipe end is not threaded) and the wire pipe (the pipe end is threaded) according to the pipe end connection mode.

The wire tube is further divided into: ordinary car wire tube and tube end thickened wire tube. Thickened wire tube can also be divided into: outer thickening (with external thread), inner thickening (with internal thread) and inner and outer thickening (with internal and external thread) and other ground wire tubes. If the wire tube is threaded, it can be divided into: ordinary cylindrical or conical thread and special thread.

Plating characteristics

Steel pipes can be divided into black tube (not plated) and plated coated tubes according to the surface coating characteristics.

The coated tubes are galvanized pipe, aluminized, chrome-plated, aluminized, and other alloyed steel tubes.

The coated tube has an outer coating tube, an inner coating tube, and an inner and outer coating tube. Commonly used coatings are plastic, epoxy, coal tar epoxy and various glass type anti-corrosive coatings. Galvanized pipes are further divided into KBG pipes, JDG pipes, threaded pipes, etc.

Folding by purpose

1. Pipes for pipes. Such as: gas pipe, steam pipe seamless pipe, oil pipeline, oil and gas trunk line pipe.

2. Tubes for thermal equipment. Such as general boiler boiling water pipes, superheated steam pipes.

3. Pipes for machinery industry. Such as aviation structural tubes, automotive semi-axle tubes, axle tubes.

4. Oil geological drilling pipe. Such as: oil drilling pipe, geological drilling pipe.

5. Tubes for the chemical industry. Such as: petroleum cracking tubes, stainless acid-resistant tubes.

6. Other departments use the tube. Such as: container tube, watch case tube.