Classification of a pipe

1, according to the production method of classification

(1) seamless - hot-rolled pipes, cold-rolled, cold drawn tubes, extruded tube, top tube (2) pipe (a) according to process sub - arc welded pipe, ERW pipe (high-frequency, low frequency), gas pipe, stove pipe (b) by weld points - longitudinally welded pipes, spiral welded pipe

2, according to the cross-sectional shape classification

(1) simple section steel - round pipe, square pipe, oval pipe, steel triangular, hexagonal steel, diamond steel, octagonal steel, steel semi-circles, other (2) complex section steel - ranging side hexagonal steel pipe, five plum-shaped steel pipe, steel pipe double convex, double concave steel, oval-shaped steel conical pipe, corrugated steel pipe, steel pipe case, other

3, classified according to wall thickness - thin-walled steel pipe, thick-walled steel pipe

4. By Application - steel pipes, thermal equipment with steel pipes, industrial machinery and steel, petroleum, geological drilling steel, container steel, chemical industry with steel pipes, steel pipes for special purposes, other

Second, the seamless steel pipe

It is a kind of hollow cross-section, no seams around the long bar of steel. Steel hollow section is used as a large number of pipes conveying fluids, such as transportation of oil, natural gas, gas, water and some solid materials, pipes and so on. Compared to other steel and solid steel bar, the same torsional strength in bending, lighter, is an economic cross-section steel, widely used in the manufacture of structural parts and mechanical parts, such as drill pipe, automotive drive shafts, bicycle rack and construction using steel scaffolding. Steel pipe manufacturing annular parts, can improve material utilization, simplify the manufacturing process, saving material and machining time, such as bearing rings, jack sets, has been widely used to make steel. Steel or a variety of conventional weapons indispensable material, barrel, barrel would have to make steel. Pipe according to different cross-sectional shapes can be divided into tube and shaped tubes. Because in the perimeter of equal conditions, the largest area of a circle with a circular tube can carry more fluid. In addition, the circular cross section to withstand internal or external radial pressure, the force is uniform, so the vast majority of pipe is pipe. However, the tube also has some limitations, such as under the conditions by plane bending, tube as good as square, rectangular tube large flexural strength, the skeleton of some farm machinery, steel and wood furniture on the popular square, rectangular tube. According to different uses should also have other special-shaped pipe cross-sectional shape.