🔍 Key Concepts

• Grade A cargo definition and its vapor hazard characteristics (flashpoint, vapor density) • Location and ventilation requirements for air intakes on tank vessels carrying flammable cargoes • Differences between open deck areas aft of cargo and enclosed spaces when flammable vapors are present

💭 Think About

• Which locations are most likely to accumulate flammable vapors, especially if there is a spill or normal venting of cargo tanks? • How do the rules treat enclosed spaces that are connected to, or contain, cargo piping or cargo-handling equipment versus open, elevated locations? • Which option best minimizes the chance that compressor intake air could contain flammable vapors from the cargo area?

✅ Before You Answer

• Verify which locations are classified as hazardous (or cargo) areas versus non‑hazardous in 46 CFR for tank vessels carrying Grade A cargo • Check whether enclosed spaces associated with cargo systems are allowed for air intakes that serve machinery or compressors • Confirm required separation (distance and elevation) between air intakes and cargo areas or sources of flammable vapor per current regulations