Learning outcomes
- Explain the key principles of pump fault finding and cavitation.
- Carry out a structured practical check or configuration task.
- Recognise common faults, risks and evidence needed for diagnosis.
Module 4 · Lesson 4
Pump fault finding and cavitation
Diagnose no-flow, low-flow, loss of prime, cavitation, seal leakage, overload and repeated cycling.
Before you begin
P&ID, trends, pressure gauges and inspection tools.
Safety: Use site procedures, approved test equipment and competent supervision. Never bypass a protection or interlock without formal control.
Step-by-step learning
- Confirm liquid availability, valve positions and suction conditions.
- Compare suction pressure, discharge pressure, flow and motor current.
- Listen for cavitation and inspect strainers, air leaks and blocked impellers.
- Review level-control deadband and minimum run/off times for cycling issues.
Ian's practical tips:
- Cavitation often sounds like gravel passing through the pump.
- Low current can indicate loss of load or no water—not necessarily an electrical improvement.
Fault-finding questions
- What should be happening, and what evidence proves it?
- Where is the last known correct signal, voltage, state or process condition?
- What changed immediately before the fault?
- Can the system be divided into smaller testable sections?
Practical activity
Create a one-page test record for this lesson. Include expected values, measured results, equipment used, risks controlled, defects found and the final proven condition.