Welded steel pipes are classified by use

According to the use, it is divided into general welded pipe, galvanized welded pipe, blown oxygen welded pipe, wire casing, metric welded pipe, roller pipe, deep well pump pipe, automobile pipe, transformer pipe, electric welded thin-wall pipe, electric welded special shape pipe and spiral welded pipe.
Ordinary welded pipe
General welding pipe to transport low pressure fluid. Made of Q195A, Q215A, Q235A steel. It can also be made of other soft steels that are easy to weld. Steel pipe to carry out water pressure, bending, flattening and other experiments, there are certain requirements on the surface quality, usually the delivery length is 4-10m, often require fixed size (or double size) delivery. The specification of the welded pipe is expressed by the nominal diameter (mm or inch). The nominal diameter is different from the actual one. The welded pipe has two kinds of ordinary steel pipe and thickened steel pipe according to the specified wall thickness, and the steel pipe is divided into two kinds with thread and without thread according to the form of the pipe end.
Galvanized steel pipe
In order to improve the corrosion resistance of the steel pipe, the general steel pipe (black pipe) is galvanized. Galvanized steel pipe is divided into hot dip galvanized and electric galvanized two, hot dip galvanized galvanized layer is thick, electric galvanized low cost.
Oxygen blow welding pipe
Used as steel blowing oxygen pipe, generally with small diameter welded steel pipe, specifications from 3/8 inch to 2 inch eight. Made of 08, 10, 15, 20 or Q195-Q235 steel strip. In order to prevent corrosion, some are aluminized.
Wire bushing
It is an ordinary carbon steel welded steel pipe, used in concrete and various structural power distribution projects, and the commonly used nominal diameter is from 13-76mm. The wall of the wire jacket is thin, and most of them are used after coating or galvanized, requiring cold bending test
Metric welded pipe
Specifications Welded steel pipe in the form of seamless pipe, with outer diameter * wall thickness mm, with ordinary carbon steel, high-quality carbon steel or general energy low alloy steel tropical, cold zone welding, or tropical welding and then made by cold drawing method. The metric welded pipe can be used as a structural part, such as a drive shaft, or to transport fluids, and the thin wall is used to produce furniture, lamps, etc., to ensure the strength and bending test of the steel pipe.
Idler tube
Used for belt conveyor roller electric welding steel pipe, generally made of Q215, Q235A, B steel and 20 steel, diameter of 63.5-219.0mm. There are certain requirements for tube bending, end face perpendicular to the center line and ellipticity, and water pressure and flattening tests are generally carried out.