The code for inspection and repairing of edge discontinuities applies to visually detected discontinuities on plate sections up to what thickness and intended for use in cyclically loaded structures?

• A. All plate sections regardless of thickness
• B. Only welded joints
• C. Only plate sections up to 4 inches (100 mm) thick intended for cyclically loaded structures
• D. Visually detected discontinuities on all plate sections up to 4 inches (100 mm) thick and intended for cyclically loaded structures

Answer: (D)

Edge discontinuity inspection and repair is limited in scope to surface-visible defects that occur at the plate edges on plates no thicker than 100 mm (4 in) and that are intended for structures experiencing cyclic loading. This means you only consider visually detectable edge flaws on plate sections within that thickness and in applications where the structure will be subjected to repeated or fluctuating loads. The option that best matches this scope states that these discontinuities are visually detected, apply to all plate sections up to 4 inches thick, and are for cyclically loaded structures. This differs from broader coverage (all plates regardless of thickness) or from focusing only on welded joints, and it also includes the specific condition of cyclic loading, which drives the need for such inspection and potential repair. For thicker plates, or for non-cyclic loading scenarios, other rules would apply. For example, a visibly cracked edge on a 3-inch plate used in a cyclically loaded member falls under this scope and would be addressed accordingly.