A CWB weld with backing is categorized under which class?

A CWB weld with backing is categorized under which class?

• A. S class
• B. A class
• C. B class
• D. C class

Answer: (A)

In this classification system, the letters denote the condition of the weld setup, specifically regarding backing. A weld made with backing is designated as A class, because the backing material alters how the weld root is supported during solidification, affecting penetration, heat flow, and inspection criteria. This distinction helps ensure the qualification and acceptance criteria match the actual welding condition. Other classes represent different backing or setup scenarios, so they do not apply to a weld formed with backing.

In this classification system, the letters denote the condition of the weld setup, specifically regarding backing. A weld made with backing is designated as A class, because the backing material alters how the weld root is supported during solidification, affecting penetration, heat flow, and inspection criteria. This distinction helps ensure the qualification and acceptance criteria match the actual welding condition. Other classes represent different backing or setup scenarios, so they do not apply to a weld formed with backing.