(1) Seamless pipes-heat pipes, cold-rolled pipes, cold-drawn pipes, extruded pipes and pipe jacking.
(2) welded pipe.
(a) according to the process-arc welded pipe, resistance welded pipe (high frequency, low frequency), gas welded pipe and furnace welded pipe.
(b) According to the weld-straight welded pipe and spiral welded pipe.
According to the cross-sectional shape
(1) Simple section steel pipes-round steel pipes, square steel pipes, oval steel pipes, triangular steel pipes, hexagonal steel pipes, diamond steel pipes, octagonal steel pipes, semicircular steel rings and others.
(2) Steel pipes with complex sections-equilateral hexagonal steel pipes, five-petal plum-blossom steel pipes, double convex steel pipes, double concave steel pipes, melon seeds steel pipes, conical steel pipes, corrugated steel pipes, watchcase steel pipes, etc.
According to caliber
According to the caliber classification, it can be divided into large-caliber seamless steel pipe and small-caliber seamless steel pipe.
By wall thickness
According to the wall thickness, it can be divided into thin-walled steel pipe and thick-walled steel pipe.
According to the purpose
Steel pipes for pipelines, thermal equipment, machinery industry, petroleum and geological drilling, containers, chemicals, special-purpose steel pipes and others.
(1) Pipe for pipeline. Such as: seamless pipes for water pipes, gas pipes, steam pipes, oil pipelines and oil and gas trunk lines. Water pipes for agricultural irrigation taps and sprinkler irrigation.
(2) Pipes for thermal equipment. Such as boiling water pipes and superheated steam pipes of general boilers, superheated pipes, large smoke pipes, small smoke pipes, arched brick pipes and high-temperature and high-pressure boiler tubes of locomotive boilers.
(3) Pipe for mechanical industry. Such as aviation structural tubes (round tubes, elliptical tubes and flat elliptical tubes), automobile semi-axle tubes, axle tubes, automobile tractor structural tubes, oil cooler tubes for tractors, square tubes, rectangular tubes for agricultural machinery, transformers and bearings.
(4) Pipes for petroleum geological drilling. Such as: petroleum drill pipes, petroleum drill pipes (square drill pipes and hexagonal drill pipes), drilling tappets, oil pipes, petroleum casings and various pipe joints, geological drill pipes (core pipes, casings, movable drill pipes, drilling tappets, clamping sleeves and pin joints, etc.). ).
(5) Pipe for chemical industry. Such as: petroleum cracking pipes, heat exchanger pipes, chemical equipment pipes, stainless acid-resistant pipes, high-pressure pipes for chemical fertilizers, pipes for conveying chemical media, etc.
(6) Other departments use pipelines. Such as: tubes for containers (tubes for high-pressure gas cylinders and general containers), tubes for instruments, tubes for watch cases, injection needles and tubes for medical devices.
Press connect
Steel pipes can be divided into: smooth pipe (with no thread at the end) and turning pipe (with thread at the end) according to the connection mode of pipe ends.