Electric resistance welding steel pipe is hot-rolled coil after molding machine, using high-frequency current skin effect and proximity effect, so that the edge of the tube is heated to melt under pressure welding squeeze rollers role to achieve production. 

Ms erw pipes advantages are following below:

A) high dimensional accuracy. the deviations of welded steel pipe is smaller than seamless steel pipe, and this is because the steel strip forming the pipe is easy to control, the high dimensional accuracy. 
B) good mechanical properties. Since the pipe is easy to control with a steel rolling, with the development of welding technology and on-line heat treatment technology, the weld properties can be controlled, and therefore ERW steel pipe elongation of 8% -10% higher than the seamless steel tubes, which because the straight seam welded carbon electricity overcast about 12% lower than seamless. 
C) high concentricity  and uniform thickness of straight seam resistance welding steel pipe. Weld after heat treatment, microstructure uniformity, with a strong ability to squeeze collapse. 
D) Because the extension of the steel is good, straight seam welded pipe flattening test electrical sister is better than seamless. 
E) ERW pipe toughness is higher than seamless steel tubes. 
F) ERW pipe is no welding dissimilar metals such as infiltration, and undergo a rigorous line heat treatment, welding performance and therefore consistent with the material properties.