Large-diameter thick-walled welded pipe: also known as welded pipe, it is formed by bending steel plate or steel strip and then welding. According to the weld form, it is divided into large diameter thick-walled welded pipe and spiral welded pipe. According to the purpose, it can be divided into ordinary welded pipes, galvanized welded pipes, oxygen-blown welded pipes, silk sleeves, metric welded pipes, idler pipes, deep well pump pipes, automobile pipes, transformer pipes, welded thin-walled pipes, welded special-shaped pipes and spiral welded pipes. Ordinary welded pipe: Ordinary welded pipe is used for conveying low-pressure fluid. Made of steel Q 195A, Q2 15A and Q235A. It can also be made of other low carbon steels that are easy to weld. Steel pipes have to undergo water pressure, bending, flattening and other experiments, which have certain requirements for surface quality. Usually the delivery length is 4- 10m, and it is often required to deliver according to the length (or double the length). The specifications of welded pipes are expressed in nominal caliber (millimeters or inches). The nominal caliber is different from the actual situation. Large-diameter thick-walled welded pipes are divided into ordinary steel pipes and thickened steel pipes according to the specified wall thickness, and steel pipes are divided into threaded pipes and non-threaded pipes according to the pipe end form. Table 6- 17 shows the dimensions of welded steel pipes.
Large-diameter thick-walled welded pipe is a general term, which is produced by steel strip. The pipes welded by high-frequency welding equipment are all called large-diameter thick-walled welded pipes. It is named after the welding of large-diameter thick-walled welded pipe is in a straight line. Among them, according to different uses, there are different subsequent production processes. (Large-diameter thick-walled welded pipe can be roughly divided into scaffold pipe, fluid pipe, silk sleeve, support pipe, guardrail tube and so on. )
Large-diameter thick-walled welded pipe is rolled by high-strength press, which has the characteristics of high precision and mild pressure resistance.