Difference between ERW and EFW

ERW is the acronym for the first letter, resistance welding.
ERW pipe and submerged arc welding pipe are significantly different, the use of non-pressurized filler metal welding, the weld is no other ingredients, relying on the skin effect of high frequency current and proximity effects, instant heating plate edge squeeze roll extrusion forging of welded joints Welding temperature. High-quality steel pipe welds require on-line or off-line heat treatment, weld zone refinement, quality ERW pipe welds and base metal toughness can reach the same level, which is submerged arc welding process can not be achieved.


EFW is the acronym for electrofusion.
Submerged arc welding (SAW) - One of the welding (EFW) is through one or more metal electrode between the consumable electrode work piece and the process in combination with the metal, the arc and metal filler material is fully melted, no pressure to fill the metal part The work is all done by electrodes.


GMAW - Electric Welding (EFW), similar to this process and submerged arc welding, but it is a protected inert gas, the effect will be better.