دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a welding technique in which the arc is maintained in a continuous stream of gas between an electrode and the pipe being welded. The semi- automatic welding apparatus consists of a spool of coiled wire that provides filler metal for the weld, a pair of driving rollers that guide the wire to the weld, a welding gun, and a supply of shielding gas. Each type of semiautomatic welding is usually identified by the type of shielding gas used;in CO2 wire welding, for example, carbon dioxide is the shielding gas.