🔍 Key Concepts

• Positive displacement vs. centrifugal pumps in diesel engine systems • Typical requirements of a lube oil system (pressure, flow, viscosity) • Common types of pumps used for lubricating oil on marine diesel engines

💭 Think About

• Does a lube oil pump need to deliver a fairly constant flow regardless of pressure changes, or is variable flow acceptable? • Which pump type is better suited for handling viscous fluids like lube oil at the pressures needed for bearing lubrication? • On real marine diesel engines you have seen or studied, what kind of pump is usually bolted to and driven by the engine for lubrication?

✅ Before You Answer

• Identify which choices are positive displacement pumps and which are dynamic (centrifugal) pumps • Eliminate pump types more commonly used for fuel transfer or general service rather than precise lubrication duty • Confirm which pump type is typically engine-driven and provides steady pressure to main bearings and other moving parts