Seamless pipes have strict requirements on cavity cleanliness and wall thickness dimensional tolerances. However, during the whole process of electric welding, due to the action of molten metal material, the thickness of the pipe at the weld will increase, and the inside and outside of the weld will be uneven.

ERW welded pipe is made by using the skin effect and proximity effect of high-frequency current to rapidly heat the edge of the pipe to the welding temperature and then extrude and weld it.

Alloy pipe is a kind of seamless steel pipe, and its performance is much higher than that of ordinary seamless steel pipe. Alloy pipes are divided into structural seamless pipes and high-pressure heat-resistant alloy pipes.

The welding of the straight seam steel pipe adopts the milling method. In addition to traditional JCO and UO technologies, some manufacturers have adopted more advanced progressive forming (PFP) technology, roll bending forming (RBE) technology. According to the production process, straight seam steel pipes can be divided into electric resistance welded pipes (ERW pipes) and submerged arc welded straight seam steel pipes (LSAW steel pipes).

The condition that the seamless steel pipe is damaged by the organic chemical or photoelectric catalytic effect of the substance is called corrosion.

The steel-plastic composite pipe is made of seamless steel pipe or hot-dip galvanized steel pipe as the base, and the inner wall (the outer wall can also be used when needed) is coated with plastic by powder melt spraying technology, and has excellent performance.