Which non-compliance affects the weld quality significantly and must be avoided?

Incomplete fusion is a significant non-compliance issue that directly affects weld quality. It occurs when the weld metal does not completely bond with the base metal, resulting in a lack of uniformity and strength in the weld joint. This can compromise the integrity of the pipeline and lead to potential failure under stress, pressure, or environmental conditions.

Quality welds require complete metallurgical bonding between the welding rod and the base metal to ensure strength and resistance to cracks and other defects. If fusion is incomplete, the joint may exhibit weak points that can lead to failures, leaks, or other operational hazards. Hence, ensuring complete fusion during the welding process is critical for maintaining the structural integrity and performance of pipelines and related facilities.

While other non-compliances like excessive slag inclusions, contaminated base metal, and dimensional inaccuracies can also impact the overall quality and performance of a weld, they do not jeopardize the fundamental bonding necessary for a reliable and safe weld joint to the same extent as incomplete fusion.