Which method is explicitly listed as an acceptable procedure for cleaning the pipe before welding?

• A. Grinding
• B. Brushing
• C. All of the above
• D. Filing

Answer: (C)

Cleaning the pipe before welding is about removing contaminants so the weld can fuse properly. In many welding procedures, multiple mechanical cleaning methods are allowed, including brushing to remove rust or scale, grinding to strip heavy oxide or paint and smooth the surface, and filing to clean edges and burrs. The question asks which method is explicitly listed as acceptable, and since the procedure typically allows several methods, the option that includes all of them is the best choice. Remember to follow the welding procedure guidelines and avoid introducing contaminants or causing damage, such as embedding abrasive particles or overheating the material.