Which statement about shielding gas in GTAW is true?

• A. It helps remove fumes
• B. It helps reduce UV light
• C. It keeps air away from the hot tungsten and molten weld metal
• D. It cools the weld area

Answer: (C)

Shielding gas in GTAW creates a protective atmosphere around the arc, the tungsten electrode, and the molten weld pool so air—especially oxygen and nitrogen in the atmosphere—cannot contact the hot metal. This prevents oxidation, porosity, and contamination of the weld, and helps maintain a stable arc. That makes the statement about keeping air away from the hot tungsten and molten weld metal the accurate description of its function. It doesn’t remove fumes—that’s a job for ventilation or fume extraction—and it doesn’t primarily reduce UV light, which is addressed with personal protective equipment and arc control rather than shielding gas. It also isn’t a coolant for the weld area; cooling is determined mainly by heat input, material, and welding speed, with gas flow having only a minor influence on convection.