🔍 Key Concepts

• Role of sacrificial zinc anodes in corrosion protection • Which engine systems have direct contact with water or seawater • Difference between internal lubrication, fuel handling, and heat removal systems

💭 Think About

• Which system parts are most likely to be exposed to electrolytes (like seawater or treated water) that can cause galvanic corrosion? • Do we usually worry about zincs where there is clean oil or fuel, or where there is water flow in and around metal parts? • On a marine diesel, which circuit often connects to heat exchangers, coolers, or raw seawater?

✅ Before You Answer

• Identify which option involves water or seawater rather than oil, fuel, or gas • Recall where zinc pencils or zinc plugs are installed on heat exchangers, coolers, or jackets • Eliminate any system where sacrificial metal particles would contaminate precision components (like injectors or bearings)