Which of the following statements is correct...

🔍 Key Concepts

• Relationship between oil density/specific gravity and the choice of dam ring in a tubular purifier • How the physical dimensions of a dam ring (inside vs outside diameter) affect the oil–water interface level • What indicates a correct oil–water interface during normal purifier operation (what you see at the oil and water outlets)

💭 Think About

• Ask yourself: is dam ring size chosen mainly because of viscosity, or because of where the oil–water interface must be held inside the bowl? • Think about how manufacturers usually mark dam rings: do larger identification numbers normally mean a larger or smaller opening? • Consider what you would actually observe at the water discharge when the interface is correctly positioned—should there be absolutely no oil, or perhaps a trace/occasional drops?

✅ Before You Answer

• Verify which fluid property (viscosity vs specific gravity/density) is used in dam ring selection tables for purifiers. • Check whether it is the inside diameter or outside diameter of the dam ring that primarily controls the interface level. • Confirm whether using the largest possible dam ring always gives the best purification, or whether oversizing can actually shift the interface to the wrong place.

Which of the following statements is correct regarding the selection of the proper size ring dam for a tubular-type lube oil purifier?

The size ring dam used depends on the viscosity of the oil being purified.

While all ring dams have the same inside diameter, the outside diameters vary.

Ring dams of larger sizes are indicated by smaller numbers.

Satisfactory purification is obtained when the ring dam is the largest size possible, and no oil is present at the water discharge.

🔍 Key Concepts

💭 Think About

✅ Before You Answer