🔍 Key Concepts

• Behavior of rotary (positive displacement) pumps when speed changes • Relationship between pump speed and slippage (internal leakage) • Effect of overspeed on mechanical wear and clearances in pump components

💭 Think About

• Think about what happens to internal leakage (slippage) when the pump runs faster than designed: does more speed always mean more effective delivery, or can losses increase? • Consider how running above rated speed affects metal-to-metal parts over time: would clearances between parts naturally get tighter or looser under extra wear? • Ask yourself whether loss of suction is more commonly related to speed being too high or problems like air leaks, clogged strainers, or speed being too low.

✅ Before You Answer

• Review how positive displacement pumps (like rotary pumps) differ from centrifugal pumps in terms of flow vs speed and slippage • Verify which condition would be a direct, likely result of operating above rated speed, not just a rare failure mode • Eliminate any options that describe a condition that would more likely occur at low speed or low flow rather than high speed/overspeed