Welded steel pipe, also known as ERW pipe, is a steel pipe made of steel plate or strip after crimping and forming, with a general fixed length of 6 meters. ERW pipe has simple production process, high production efficiency, a variety of specifications, less equipment investment, but its general strength is lower than the seamless steel pipe.
General ERW pipe: General ERW pipe is used to transport low-pressure fluid. It is made of Q195A, Q215A and Q235A steel. It can also be made of other mild steel that is easy to weld. Water pressure, bending, flattening and other tests shall be carried out for steel pipes, with certain requirements for surface quality. Generally, the delivery length is usually 4-10m, and the delivery is required to be fixed length (or multiple length).
The specification of the welded pipe is indicated by the nominal diameter (mm or inch). The nominal diameter of the welded pipe is different from the actual one. According to the specified wall thickness, there are two types of welded pipe: ordinary steel pipe and thickened steel pipe. According to the form of pipe, the steel pipe is divided into two types: with thread and without thread.
Galvanized steel pipe: in order to improve the corrosion resistance of steel pipe, the general steel pipe (clarion) is galvanized.
Galvanized steel pipe is divided into two types: hot-dip galvanizing and electric-dip galvanizing. The thickness of the hot-dip galvanizing layer makes the cost of electro galvanizing low.