🔍 Key Concepts

• function and purpose of fuel oil settling tanks in marine fuel systems • difference between settling vs service/storage tanks • how water and sludge are removed from fuel oil

💭 Think About

• Think about what happens when fuel oil is left undisturbed in a tank—what happens to water and heavy solids over time? • Which tank in the fuel system is normally used to supply fuel directly to the engines: the settling tank or another type of tank? • Does a settling tank have just one main purpose, or can its design allow it to serve more than one of the listed functions?

✅ Before You Answer

• Identify which option refers to separation by gravity of water and solids from fuel oil • Decide whether a settling tank is the same as a service tank/day tank used for immediate engine supply • Confirm whether the tank’s primary function is storage, purification, or a combination of processes described in the options