During pipe repairs, which welding discontinuity is always unacceptable?

During pipe repairs, which welding discontinuity is always unacceptable?

• A. Porosity only
• B. Lack of penetration only
• C. Cracks and Inadequate fusion
• D. Surface cracks only

Answer: (C)

Welding repairs must produce a sound bond with full fusion and no cracks. Cracks are a fracture path that can grow under service conditions, leading to leakage or catastrophic failure, so any crack is not acceptable in a repair. Inadequate fusion, meaning the weld did not properly fuse with the base metal or previous weld passes, creates weak areas that can fail under pressure; such discontinuities compromise the integrity of the repaired joint and require removal and re-welding with proper technique. Porosity can sometimes be tolerated within established limits, and lack of penetration depends on the joint design and service requirements, so they aren’t universally unacceptable. The combination of cracks and inadequate fusion covers the discontinuities that are inherently unacceptable in pipe repairs.

Welding repairs must produce a sound bond with full fusion and no cracks. Cracks are a fracture path that can grow under service conditions, leading to leakage or catastrophic failure, so any crack is not acceptable in a repair. Inadequate fusion, meaning the weld did not properly fuse with the base metal or previous weld passes, creates weak areas that can fail under pressure; such discontinuities compromise the integrity of the repaired joint and require removal and re-welding with proper technique. Porosity can sometimes be tolerated within established limits, and lack of penetration depends on the joint design and service requirements, so they aren’t universally unacceptable. The combination of cracks and inadequate fusion covers the discontinuities that are inherently unacceptable in pipe repairs.