What minimum width band must be cleaned on a pipe before welding?

• A. 1/2 inch or wider
• B. 1 inch or wider
• C. 2 inches or wider
• D. 3 inches or wider

Answer: (B)

A clean surface around the weld area is essential for a sound GTAW root pass on pipe. Contaminants like oil, grease, moisture, rust, scale, or paint in the immediate joint area can cause porosity, lack of fusion, or hydrogen-related defects. Cleaning a band around the weld—at least one inch wide—ensures the metal that actually fuses and is heat-affected is free of contaminants, providing a reliable, oxide-free surface for fusion and stable welding conditions. Using a band this wide gives a safe, practical margin to avoid any residual contamination near the weld. Cleaning less than this increases the risk of defects, while cleaning more than this isn’t typically required and wastes time.