Which type of weld requires continuous special inspection?

The requirement for continuous special inspection is primarily associated with plug and slot welds due to their unique structural characteristics and the critical nature of their applications. These types of welds are often utilized in situations that require significant strength and integrity, such as in the fabrication of structural components where reliability is paramount.

Plug and slot welds are made by welding the edges of a hole in one part to the surface of another part, which can lead to complex stresses in the weld area. Given these factors, the potential for defects such as incomplete penetration or insufficient fusion is heightened. Continuous special inspection helps ensure that these welds meet stringent quality control standards throughout the welding process, ultimately contributing to the safety and performance of the finished structure.

In contrast, other types of welds like fillet, butt, and staggered welds may not necessitate the same level of oversight because they typically do not pose as high a risk in terms of structural failure or require such rigorous inspection protocols. While inspections are still important across various welding types, the specific nature of plug and slot welds typically mandates a higher level of continuous scrutiny.