Seamless steel pipe and welded steel pipe (with seam tube) two major categories. According to sectional shape can be divided into circular tubes and special-shaped pipes, widely used is round steel pipe, but also some square, rectangular, semi-circular, hexagonal, equilateral, octagonal and other profiled steel pipe. To withstand the fluid pressure of the steel pipe to carry out hydraulic test to test its pressure-resistant capacity and quality, under the prescribed pressure does not occur leakage, wetting or expansion for the qualified, some steel tubes should also be based on the standard or demand-side test, expansion test, flattening test.
1. Classification by production method
(1) Seamless steel tube-hot-rolled pipe, cold-drawn pipe, extruded pipe, top tube, cold rolling pipe
(2) Welded pipe
(a) According to the technology-arc welded pipe, resistance welded pipe (high-frequency, low-frequency), gas welded pipe, furnace pipe
(b) by weld seam-straight seam welded pipe, spiral welded pipe
2. Classification by sectional shape
(1) Simple section steel pipe-round steel pipe, square steel pipe, oval steel pipe, triangular steel pipe, hexagonal steel pipe, rhombic steel pipe, octagonal steel pipe, semi-circular steel circle, other
(2) Complex section steel tube-unequal hexagonal steel pipe, five-petal plum-shaped steel pipe, double convex steel pipe, double concave steel pipe, melon seed-shaped steel pipe, conical steel pipe, corrugated steel pipe, steel tube, other
3, according to wall thickness classification-thin-walled steel pipe, thick-walled steel pipe
4, by use classification-pipe, heat equipment steel pipe, mechanical industry steel pipe, petroleum, geology drilling steel pipe, container steel pipe, chemical industry steel pipe, special purpose steel pipe, other.