Question 68 QMED04 - Boiler Technician-Watertender

The Correct Answer is A **Why Option A ("Diesel Oil Service Tank") is correct:** The Diesel Oil Service Tank (sometimes called the Day Tank) is specifically designed and positioned to supply readily usable, filtered fuel directly to the diesel engines, including the main engines and crucial auxiliary engines like the emergency generator. Because the emergency generator must be capable of starting immediately and reliably under blackout conditions, it requires a dedicated, clean fuel supply located near the generator, which is the function of the Service Tank in the fuel oil system layout (as typically depicted in marine or stationary power plant illustrations like MO-0058). **Why the other options are incorrect:** * **B) Diesel Oil Settling Tank:** The Settling Tank's primary function is to receive bulk fuel, allow heavier impurities and water to separate out through gravity over time, and prepare the fuel for further purification (e.g., by a purifier/centrifuge). It is an intermediate storage and treatment stage, not the direct supply source for the operating generator. * **C) Diesel Oil Boiler Tank:** This term is generally non-standard in a typical diesel fuel system layout. Boilers are typically fired by Heavy Fuel Oil (HFO) or Marine Gas Oil (MGO), and the tank supplying the boiler would be referred to as the HFO or MGO Service Tank, separate from the tanks supplying the emergency diesel generator. * **D) Diesel Oil Booster Tank:** This term is not standard terminology for a component within the main fuel storage or supply path. A "booster" function typically refers to a pump (a booster pump) used to increase pressure, not a storage tank.