🔍 Key Concepts

• disk-type centrifugal purifier bowl and interface location • function of the discharge (gravity) ring in controlling the water/oil interface • relationship between oil properties and separation in a centrifugal field

💭 Think About

• Ask which property will change the level of the oil/water interface inside the bowl for the same machine and flowrate. • Think about what the discharge ring actually "sees": is it flow quantity, oil thickness when flowing, machine speed, or a density-related effect? • Consider what happens if you switch from diesel oil to a much heavier fuel oil but do not change the discharge ring size—what separation problem would appear?

✅ Before You Answer

• Identify which choice is a fluid property that directly affects how heavy the oil is compared to water. • Decide whether the ring size is set once for the machine, or must be changed when you treat different oils in the same purifier. • Verify that the selected factor would change the position of the interface between oil and water, not just the throughput or RPM.