🔍 Key Concepts

• 46 CFR Part 58 – Engineering Systems (look for the section on refrigeration and pressure vessels) • Pressure relief protection – why relief valves are used on closed or isolated pressure vessels • Maximum allowable working pressure (MAWP) – and how safety valve settings are normally related to MAWP

💭 Think About

• Which answer choices talk about pressure relief rather than inspections, storage, or handling? • Think about standard practice for safety valves on pressure vessels: are they usually set at, above, or below the maximum allowable working pressure? • If a vessel can be isolated and heated (for example by ambient temperature), what must prevent the pressure from rising to a dangerous level?

✅ Before You Answer

• Verify in 46 CFR Part 58, Subpart 58.20 (Refrigeration Systems) which specific wording is used for relief valve settings on refrigerant pressure vessels. • Check whether the regulation mentions a percentage of maximum allowable working pressure (MAWP) for the relief setting. • Confirm that the required protection is an automatic pressure‑relieving device, not just periodic testing or storage requirements.