🔍 Key Concepts

• Effect of impeller-to-wear-ring clearance on centrifugal pump discharge pressure and efficiency • How suction side restrictions (like strainers) typically show up in pump readings (pressure, flow, noise, NPSH issues) • What mechanical wear (bearings, shaft) usually changes in pump behavior (vibration, alignment, seal condition)

💭 Think About

• If the pump casing, speed, and system remain the same, which internal change inside the pump would gradually reduce its ability to build pressure over several years? • Which option would most likely cause symptoms like cavitation, noise, or suction vacuum changes instead of a smooth, long‑term drop in discharge pressure? • Which condition is most consistent with a slow, progressive performance loss since overhaul rather than a sudden or intermittent problem?

✅ Before You Answer

• Compare which option directly affects the hydraulic sealing between high‑ and low‑pressure sides of the impeller • Ask: would this condition usually cause a sudden drop in pressure or a gradual decline over years? • Decide which condition is most likely to show up first as vibration/noise or overheating, rather than as a simple pressure decrease in the log book