🔍 Key Concepts

• Centrifugal pump performance – how flow, head (pressure), and power change when you restrict suction vs. discharge side • Causes of low discharge pressure – internal leakage between impeller and casing vs. suction problems like air, cavitation, or low NPSH (net positive suction head) • Lantern rings vs. wearing rings – what each component does in a pump and which one affects developed head/pressure

💭 Think About

• When a centrifugal pump slowly loses its ability to build pressure over time (not suddenly), what kind of wear or internal condition usually causes that? • What happens to pump capacity and discharge pressure if you start closing the suction valve compared to closing the discharge valve? Which action is generally avoided? • Which component in the list directly affects internal recirculation (slip) between high-pressure and low-pressure areas in the pump, and thus the discharge pressure?

✅ Before You Answer

• Confirm which parts of a centrifugal pump control internal clearances between the impeller and casing (affecting leakage and pressure). • Verify that throttling on the suction side is usually undesirable because it can reduce NPSH and promote cavitation. • Distinguish the function of lantern rings (sealing/flush water distribution) from wearing rings (controlling leakage and maintaining pump efficiency).