🔍 Key Concepts

• 46 CFR requirements for fuel systems on small passenger vessels • Purpose of fuel tank venting (preventing pressure/vacuum and avoiding fuel in the vent line) • Design features that prevent blockage and fuel accumulation in vent piping

💭 Think About

• Think about what could happen if fuel gets trapped in the vent line—how would that affect pressure in the tank during filling or temperature changes? • Consider why regulations care about both the connection point on the tank and the routing of the vent line all the way to its outlet. • Ask yourself: what extra safety function does a U-bend with a fine corrosion‑resistant screen provide at the termination of a vent?

✅ Before You Answer

• Verify where on the tank a vent connection best allows air to escape and prevent vapor pockets. • Check which vent line routing best ensures liquid fuel drains back to the tank instead of sitting in the vent line. • Confirm the purpose of a wire mesh screen at the vent outlet (e.g., flame protection, insect/debris exclusion) and whether this is a common regulatory feature.