According to 46 CFR regulations pertaining to periodic tests and inspections as related to piping systems, under what circumstances is an internal inspection of a non-metallic expansion joint performed by the marine inspector?

Correct Answer: Option D — An internal inspection of the non-metallic expansion joint is performed whenever an external inspection reveals excessive wear or other signs of deterioration or damage.

46 CFR regulations require non-metallic expansion joints to be inspected for signs of degradation. While external visual checks are routine, an internal inspection is mandated only when external indicators, such as cracking, bulging, or excessive wear, suggest that the structural integrity of the joint has been compromised.