Classification of steel pipes


seamless steel tubeThe steel tube has a closed annular cross-section, which is more resistant to bending and more rigid than the circular steel and square steel with the same cross-section area. Therefore in the fluid transmission, the mechanical structure, the construction, the national defense, the thermal equipment, the petroleum geology drilling, the chemical industry and so on many industries obtains the widespread application. It is known as the "blood vessel" of industry.

The classification method of steel pipe is very much. According to the cross-sectional shape, it can be divided into circular pipe and special-shaped pipe (EN10219 square steel pipes, S235JR rectangular steel pipes, hexagonal pipe, oval pipe, etc.). According to the shape of longitudinal section, it can be divided into equal section pipe and variable section pipe (conical pipe, ladder pipe, etc.). According to the material, it can be divided into carbon steel pipe (API 5L GR B steel pipe, ASTM A106 carbon steel pipe, ASTM A53 carbon steel pipe etc.) and alloy steel pipe (Cylinder Pipe etc.). According to the ratio of outer diameter of steel tube to wall thickness (D/s), it can be divided into extra-thick wall tube (D/s < 10), heavy wall steel pipe (D/s 1, 10, 20), thin wall steel pipe (D/s: 20, 40), ultra-thin wall tube (D/s > 40). According to the production mode, can be divided into seamless steel pipe and welded steel pipe. According to the surface characteristics of steel tube, it can be divided into coated tube (outer coating tube, inner coating tube, aluminized tube, galvanized steel pipe) and black steel pipe (uncoated tube).

With the progress of science and technology and the change of the market, the bimetal composite copper pipe, metal and non-metal composite steel pipe also get rapid development because of its special performance.