What is the main purpose of visual inspection in welding?

The primary purpose of visual inspection in welding is to detect surface defects and ensure compliance with specifications. This process involves examining the weld bead and surrounding areas for any irregularities such as cracks, porosity, undercuts, or lack of fusion, which can compromise the integrity of the weld joint. Visual inspection serves as the first line of defense in quality control, helping to identify issues that could lead to failure during service. It ensures that the weld meets the necessary codes and standards required for safety and reliability in pipeline operations.

While measuring the thickness of the weld, assessing heat treatment, and evaluating aesthetics might be aspects of a comprehensive welding inspection program, they are not the main focus of visual inspection. The emphasis on surface defects is crucial because these imperfections can have significant impacts on the mechanical properties of the welded joint and the overall performance of the pipeline.