The high-frequency welded spiral finned tube is used to heat the steel strip and the outer surface of the steel tube until the plastic state or melting by using the skin effect and proximity effect of high-frequency current while the steel strip is wound on the steel tube. The welding is completed under a certain pressure of the wound steel strip. This high frequency welding is a solid phase welding. Compared with mosaic, brazing ( or integral hot galvanizing ) and other methods, it is more advanced in terms of product quality ( the welding rate of fins is high, up to 95 % ), productivity and automation.
