In a tank vessel constructed in 1970, carying grade A, B, C, or D liquid cargo, what is required to isolate cargo pumps from sources of vapor ignition?

Correct Answer: Option D — gastight bulkheads

Title 46 CFR structural rules require gastight bulkheads to effectively isolate cargo pumps and pumprooms from adjacent spaces containing potential sources of vapor ignition, safeguarding the vessel against catastrophic explosions.