SWI’s Gas Tungsten Arc Welding (GTAW) process uses an arc between a non-consumable electrode and the work piece to produce a weld. The weld area is protected from atmospheric contamination by an inert gas such as argon, and a constant current power supply controls the energy across the arc. The arc is concentrated on the weld joint while the piece (or torch) is manipulated at a constant speed. Most welds are auto-genus, with filler material used as required.