🔍 Key Concepts

• Positive displacement pumps and how they move fluid compared to centrifugal pumps • Key features of helical gear pumps (tooth shape, smooth flow, priming ability) • Why oil (a viscous liquid) needs certain pump characteristics

💭 Think About

• Which option describes a characteristic that actually helps move viscous oil reliably and steadily? • Does the feature mentioned in each choice sound like it would improve suction and priming, or is it unrelated/exaggerated? • Which statement lines up with what you know about how gear pumps generally work (tight clearances, limited leakage, steady flow)?

✅ Before You Answer

• Ask yourself: do all gear pumps have stuffing boxes, and do they completely eliminate leakage? • Think about whether positive displacement pumps are usually considered good at self-priming and high suction lift, especially with viscous fluids like oil. • Remember that gear pumps typically rely on close clearances to limit slip (internal leakage). Would a design that says close clearances are "not necessary" make sense?