The FO system provides what?

• A. Clean filtered fuel at proper pressure and temperature
• B. Filtered air for the engine room
• C. Lubricated fuel lines at ambient temperature
• D. Raw fuel at high pressure

Answer: (A)

The main idea is that the fuel oil (FO) system conditions the fuel so it can be used reliably by the engine. It cleans the fuel by filtering out contaminants, heats or cools it to the right temperature to achieve the proper viscosity for accurate metering and atomization, and then delivers it at the correct pressure to the fuel nozzles. This combination—clean fuel, the right temperature to control viscosity, and the correct pressure for proper injection—ensures efficient combustion, smooth operation, and protection of pumps and injectors.

Other options aren’t correct because they describe different systems: filtered air for the engine room belongs to the air system, not the FO system; lubricated fuel lines at ambient temperature would leave the fuel too viscous or not meet system requirements; raw fuel at high pressure would bypass filtration and temperature conditioning, risking injector damage and unstable combustion.