🔍 Key Concepts

• Gasoline vapor behavior and why venting is critical on small passenger vessels • Basic requirements for fuel tank vent design on inspected small passenger vessels in 46 CFR Subchapter T • The relationship between vent size, vent location, and termination (where the vent opens to atmosphere)

💭 Think About

• Think about what happens to gasoline vapors when a tank is being filled, heated by the sun, or in rough seas. How must the vent be arranged so vapors can always escape safely? • How does the cross‑sectional area (size) of the vent line relate to the safe relief of pressure in the tank? Would a very small vent be acceptable? • If you only did one of the listed design features (U-bend termination, minimum size, or connection at the tank’s highest point), would that alone be enough for safe and continuous venting under all conditions?

✅ Before You Answer

• Check which options deal with where the vent connects to the tank versus where it terminates on the vessel. • Verify which option addresses a minimum vent size requirement and why that matters for pressure relief and vapor flow. • Ask yourself: do current safety standards for gasoline systems usually require just one design feature, or a combination of location, termination, and size requirements?