Electric Resistance Welded Steel Pipe Usage:Used for low pressure liquid delivery, such as water, ... . ERW :Electric Resistance Welded pipe HFI:High Frequency Induction weld pipe EFW:Electric Fusion Welded Pipe Standard:API 5L, API 5CT, ASTM 53, EN10217, DIN 2458 ... :API 5L : GR B, X42, X46, X56, X60, X65, X70 ASTM A53: GR A, GR B, GR C EN: S275, S275JR ...