Electric Resistance Welding Pipe(ERW steel pipe) is hot-rolled coil after forming machine, the use of high-frequency current skin effect and proximity effects, the tube edge heating and melting, squeeze roller under pressure welding to achieve production.

There are significant differences in the welding methods between high frequency welded pipe and submerged arc welded pipe. As the welding is done instantly at high speed, the difficulty of ensuring the quality of welding is much higher than that of submerged arc welding.