Classification of steel pipe

Steel pipe can be divided into two categories according to the production method: seamless steel pipe and seamed steel pipe. Seamed steel pipe is referred to as straight seam pipe.

1.Seamless steel pipe can be divided into two categories according to the production method: hot rolled seamless pipe, cold drawn pipe, precision steel pipe, hot expanded pipe, cold rolled pipe and extruded pipe. Seamless steel pipe is made of high-quality carbon steel or alloy steel, hot rolled, cold rolled (drawn).

2. Welded steel pipe is divided into furnace welded pipe, electric welding (resistance welding) pipe and automatic arc welding pipe because of its welding process, because of its welding form is divided into two kinds of straight seam welded pipe and spiral welded pipe, because of the shape of its end is divided into round welded pipe and shaped (square, flat, etc.) welded pipe. Steel pipe according to the pipe material (i.e., steel) can be divided into: carbon pipe and alloy pipe, stainless steel pipe and so on. Carbon pipe can be divided into ordinary carbon steel pipe and high-quality carbon structural pipe. Alloy pipe can be divided into: low alloy pipe, alloy structural pipe, high alloy pipe, high strength pipe. Bearing tube, heat-resistant and acid-resistant stainless steel tube, precision alloy (such as logging alloy) tube and high-temperature alloy tube.

Classification by use

1. Pipes for piping. Such as: water, gas pipe, seamless pipe for steam pipeline, oil pipeline, oil and gas trunk line pipe. Agricultural irrigation tap with pipe and sprinkler irrigation pipe, etc..

2. Pipes for thermal equipment. Such as boiling water pipe for general boiler, superheated steam pipe, superheated pipe for locomotive boiler, big smoke pipe, small smoke pipe, arching brick pipe, and high temperature and high pressure boiler pipe.

3. Pipes for mechanical industry. Such as aviation structural tube (round tube, oval tube, flat oval tube), automobile half-axle tube, axle tube, automobile tractor structural tube, tractor oil cooler tube, square tube and rectangular tube for agricultural machinery, transformer tube and bearing tube, etc..

4. Petroleum and geological drilling pipe. Such as: oil drilling pipes, oil drilling rods (square and hexagonal drilling rods), drilling jerks, oil pipes, oil casing and all kinds of pipe joints, geological drilling pipes (core pipe, casing, active drilling rods, drilling jerks, press hoops and pin joints, etc.).

5. Pipes for chemical industry. Such as: petroleum cracking pipe, chemical equipment heat exchanger and piping pipe, stainless acid-resistant pipe, high-pressure pipe for chemical fertilizer and pipe for transporting chemical media.

6. Pipes for other sectors. Such as: container tubes (high-pressure cylinder tubes and general container tubes), instrumentation tubes, watch case tubes, injection needles and their medical equipment tubes.

Coating Characteristics

Steel pipe can be divided into: black pipe (not coated) and coated pipe according to the surface coating characteristics.

Coated tubes include galvanized tubes, aluminum-plated tubes, chromium-plated tubes, aluminum-bleached tubes, and other alloy-layered tubes.

The coated pipes are external coated pipes, internal coated pipes, internal and external coated pipes. Usually used coatings are plastic, epoxy resin, coal tar epoxy resin and a variety of glass-type anticorrosive coating materials. Galvanized pipe is also divided into KBG pipe, JDG pipe, threaded pipe and so on.

According to the connection method

Steel pipe can be divided into: light pipe (pipe end without thread) and wire pipe (pipe end with thread) according to the pipe end connection.

Turned wire pipe can be divided into: ordinary turned wire pipe and pipe end thickened turned wire pipe.

Thickened car silk tube can also be divided into: external thickening (with external threads), internal thickening (with internal threads) and internal and external thickening (with internal and external threads) and other ground car silk tube.

The threaded pipe can also be divided into ordinary cylindrical or conical threads and special threads according to the thread type.

In addition, according to the user's needs, the tube is generally equipped with pipe fittings for delivery.

According to section shape

Steel pipe products of steel and varieties of specifications are extremely diverse, its performance requirements are also a variety of. All these should be differentiated with the user requirements or changes in working conditions. Usually, steel pipe products are categorized according to cross-section shape, production method, pipe material, coupling method, plating and coating characteristics and uses.

According to the cross-section shape of steel pipe can be divided into: round steel pipe and shaped steel pipe.

Shaped steel pipe refers to a variety of non-circular cross-section of the steel pipe. Among them are: square tube, rectangular tube, oval tube, flat ellipsoid tube, half-round tube, hexagonal tube, hexagonal inner round tube, unequal hexagonal tube, equilateral triangular tube, five-pronged plum blossom tube, octagonal tube, convex tube, double-convex tube. Double-concave tube, multi-concave tube, melon tube, flat tube, rhombus-shaped tube, star-shaped tube, parallelogram tube, ribbed tube, drip tube, internal finned tube, twisted tube, B-type tube, D-type tube and multi-layer tube.

According to the shape of longitudinal section, steel pipe is divided into: equal section steel pipe and variable section steel pipe. Variable cross-section (or variable cross-section) steel pipe refers to the pipe length along the direction of the cross-section shape, internal and external diameters and wall thicknesses, such as cyclical or non-cyclical changes in the steel pipe. The main ones are: outer conical tube, inner conical tube, outer stepped tube, inner stepped tube, periodic section tube, corrugated tube, spiral tube, steel tube with heat sink and barrel with compound line.