Question 290Safety & Environmental - Assistant Engineer

The correct answer is D) 12 years. According to 46 CFR Part 147, which covers requirements for pressure vessels used on vessels, a cylinder used for storing CO2 in a fixed firefighting system must be hydrostatically retested and restamped every 12 years. This is specified in 46 CFR 147.60(b), which states that such pressure vessels must be inspected and tested at least once every 12 years. The other answer choices are incorrect because they do not align with the 12-year requirement in the regulations. Calendar year, 5 years, and 8 years are all shorter intervals than the 12-year period mandated by 46 CFR Part 147 for these types of CO2 storage cylinders.