1. Cavitation
Symptoms: Grinding noise, vibration, performance drop, impeller pitting
Solution: Increase suction pressure, reduce fluid temperature, or add an inducer; also ensure 10–20 percent NPSH margin .
2. Seal Leakage
Symptoms: Fluid seepage at shaft, frequent seal replacements .
Solution: Inspect mechanical seals and O‑rings; replace hardened or damaged seals; check casing alignment and operating pressure .
3. Vibration or Noise
Symptoms: Excessive vibration (>0.3 in/s), rattling, whining .
Solution: Check for shaft or coupling misalignment, imbalanced impeller, worn bearings; use laser alignment and vibration monitoring tools .
4. Reduced Flow or Low Flow Rate
Symptoms: Lower than expected delivery rate .
Solution: Clear clogged inlet or impeller; inspect wear; ensure pump matches required flow specs .
5. Overheating Motor
Symptoms: High motor temperature, heat-related failure .
Solution: Lubricate bearings properly, ensure adequate cooling, confirm correct power supply and motor sizing .
6. Power Consumption Too High
Symptoms: Spike in electricity usage .
Solution: Identify operating point far from BEP; adjust system operation; consider impeller trimming or speed control.
7. Air Entrainment or Running Dry
Symptoms: Air bubbles, sporadic flow, seal damage .
Solution: Fix suction leaks, ensure sufficient priming, use pump fit for entrainment conditions .
8. Bearing Failure
Symptoms: Noise, heat, vibration, shaft play .
Solution: Replace worn bearings; realign shafts to maintain BEP operation; follow ANSI/HI support guidelines.
9. Cavitation‑Related Wear and Corrosion
Symptoms: Premature impeller and casing wear .
Solution: Beyond cavitation correction, select erosion-resistant materials per ANSI/HI lining guidelines.
10. Frequent Clogging or Solids Build‑Up
Symptoms: Reduced efficiency, blockages .
Solution: Install strainers or filters upstream; choose impeller types designed for solids; schedule regular cleaning and inspections.
Quick Fixes Checklist
- Increase suction pressure and temperature control to prevent cavitation
- Inspect and replace seals and O-rings as needed
- Perform shaft alignment and vibration analysis
- Keep inlet and impeller clean to maintain flow
- Recharge lubrication and check motor operating conditions
- Monitor power draw to ensure efficient operation
- Confirm priming and airtight suction lines
- Replace bearings proactively
- Use erosion‑resistant materials if cavitation persists
- Filter solids before pump to prevent clogging
