What is a common reason for the rejection of welds?

Excessive porosity is a well-recognized reason for the rejection of welds because it can significantly weaken the integrity of the welded joint. Porosity refers to the presence of small gas pockets or holes within the weld bead, which can compromise the strength, ductility, and overall performance of the weld under stress. The formation of pores can be caused by various factors such as contamination, moisture in the welding environment, improper gas shielding, and inadequate welding techniques.

When welds contain excessive porosity, they fail to meet the quality standards set forth in industry codes and specifications, including those outlined in API 1104. Inspectors often use non-destructive testing methods to identify and quantify porosity, and any weld with unacceptable levels of porosity would be deemed unsuitable for service.

Recognizing and addressing issues related to excessive porosity is crucial during the welding process to ensure the structural integrity and safety of pipelines and related facilities.