How are stainless steel pipes classified?
Stainless steel pipes are divided into ordinary carbon steel pipes, high-quality carbon structural steel pipes, alloy structural pipes, alloy steel pipes, bearing steel pipes, stainless steel pipes and bimetal composite pipes, coated pipes and coated tubes used to save precious metals and meet special requirements. The types and uses of stainless steel pipes are diverse, and the technical requirements and production methods are also different. At present, the outer diameter of the steel pipe is 0.1-450mm, and the wall thickness is 0.01-250mm. In order to distinguish its characteristics, the steel pipe is usually classified according to the following methods.
Production method
Stainless steel pipe according to the production method is divided into seamless pipe and welded pipe two categories. Seamless steel pipe can also be divided into hot rolled pipe, cold rolled pipe, cold drawn pipe, extrusion pipe and so on. Cold-drawn pipe and cold-rolled pipe are the secondary processing of steel pipe; The welded pipe is divided into straight seam welded pipe and spiral welded pipe.
Section shape
Stainless steel pipe according to its section shape can be divided into circular pipe and shaped pipe. The special-shaped tubes have rectangular tubes, diamond tubes, elliptic tubes, hexagonal tubes, octagonal tubes and various asymmetric tubes of different sections. Profiled tubes are widely used in various structural parts, tools, mechanical parts and so on. Compared with the circular tube, the shaped tube generally has a larger moment of inertia and section modulus, and has a larger bending and torsional resistance, which can greatly reduce the weight of the structure and save steel.
Stainless steel pipe according to its longitudinal shape can be divided into equal section pipe and variable section pipe. Variable section pipe has conical pipe, stepped pipe, periodic section pipe and so on.
Pipe end shape
Stainless steel pipe can be divided into smooth pipe and threaded pipe (with rebar steel pipe) according to the state of the pipe end. Car thread pipe can also be divided into ordinary car thread pipe (low-pressure pipe for conveying water, gas, etc., connected with ordinary cylinder or cone pipe thread) and special thread pipe (pipeline for oil and geological drilling, important car thread pipe connected with special thread). For some special pipes, in order to compensate for the influence of the thread on the strength of the pipe end, the pipe end is usually thickened before the thread is turned (internal thickening, external thickening or internal and external thickening).
Use classification
According to the use can be divided into oil well pipe (casing, tubing, drill pipe, etc.), pipeline pipe, boiler pipe, mechanical structure pipe, hydraulic support pipe, gas cylinder pipe, geological pipe, chemical pipe (high-pressure fertilizer pipe, oil cracking pipe), ship pipe, etc.
