🔍 Key Concepts

• density difference between fuel oil and lube oil • how gravity settling tanks/purifiers work on ships • what filtering is good at removing (type and size of contaminants)

💭 Think About

• Think about whether fuel oil and lube oil are chemically similar liquids or solid/liquid mixtures. Which process works better for separating similar liquids? • Ask yourself: does a filter normally separate two mixed liquids, or does it separate solids from liquids? • Consider what happens to heavier and lighter oils if you let the mixture sit undisturbed in a tank for a period of time.

✅ Before You Answer

• Verify what filters on board are designed to remove (solids vs. another liquid). • Consider how settling tanks and purifiers/clarifiers use gravity and centrifugal force to separate oils of different densities. • Be clear whether each method can realistically return the lube oil to near-original condition, not just trap dirt.