🔍 Key Concepts

• 46 CFR requirements for engine exhaust systems on inspected vessels • Differences between backfire flame arresters and exhaust manifolds • How cooling and insulation are handled for hot exhaust components

💭 Think About

• Which of these options sounds like it is mixing up requirements for carburetor/intake systems with exhaust manifolds? • Think about what would actually make sense from a safety and practicality standpoint on a real vessel: cooling tied to engine operation or something that could fail when the engine is running? • Which option uses very specific materials and dimensions that sound like an older or outdated practice rather than a general regulatory requirement?

✅ Before You Answer

• Review 46 CFR sections dealing specifically with internal combustion engine exhaust systems, not intake systems. • Confirm what 46 CFR says about water‑jacketed exhaust manifolds and how their cooling water is supplied. • Check whether 46 CFR requires a backfire flame arrester on the exhaust side or on the air intake/carburetor side of gasoline engines.