During pump testing, if flow is degraded by 5% or more, what action is indicated?

• A. No action
• B. The report should indicate an investigation
• C. Immediate replacement of the pump
• D. Electrical inspection only

Answer: (B)

A noticeable drop in pump performance during testing signals a deviation that must be evaluated. If flow is 5% or more below the expected value, it indicates potential issues in the pump, piping, or instrumentation that should be investigated and documented. The correct action is to flag this condition in the report and initiate a formal investigation to identify root causes—such as impeller wear, suction line restrictions, valve misadjustments, air entrainment, or gauge calibration problems—and determine the appropriate corrective steps.

Choosing no action would ignore a measurable performance change, which isn’t appropriate. Replacing the pump immediately is premature based solely on a 5% drop unless other critical symptoms are present. Restricting the response to an electrical inspection only doesn’t address the hydraulic or mechanical factors that affect flow.