Question 1536 Deck General

The correct answer is C) 90%. According to the regulations for inert gas systems on ships, the high pressure alarm in the main vapor collection line must be set to activate at 90% of the lowest relief valve setting. This ensures that the alarm sounds before the pressure reaches the relief valve activation point, allowing the crew to respond and address the pressure buildup before a potential release or system failure. The other options are incorrect because 70% and 80% would be too low, while 95% would be too high, and would not provide the necessary margin for the alarm to activate before the relief valve.