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Pump Troubleshooting Guide: Common Faults, Causes, and Remedies
GC Series Horizontal Multistage Boiler Feed Pump – Hot Water Type
This guide summarizes typical pump operating faults, their likely causes, and recommended corrective actions. It is intended for operators and maintenance personnel working with industrial and commercial pump systems, helping them quickly diagnose problems and restore reliable performance.
1. Pump Does Not Prime; Pressure and Vacuum Gauge Needles Fluctuate
Possible causes:
- Insufficient priming water inside the pump
- Air leakage in the pipeline or at instrument connections
Recommended solutions:
- Add sufficient liquid to fully prime the pump
- Tighten and seal all leaking joints and interfaces
2. Pump Does Not Prime While the Vacuum Gauge Indicates High Vacuum
Possible causes:
- Foot valve not opened or blocked
- Excessive resistance in the suction pipeline
- Suction lift too high
Recommended solutions:
- Inspect, correct, or replace the foot valve
- Optimize or replace the suction pipeline to reduce resistance
- Lower the suction lift to within the pump’s allowable range
3. Pressure Gauge Shows Pressure but the Pump Delivers No Water
Possible causes:
- Discharge pipeline resistance too high
- Incorrect motor rotation direction
- Impeller passages blocked
- Pump speed too low
Recommended solutions:
- Inspect or shorten the discharge pipeline to reduce resistance
- Check and correct the motor rotation direction
- Remove piping connections if necessary and clean the impeller
- Increase pump speed to the rated value
4. Pump Flow Rate Is Lower Than the Design Value
Possible causes:
- Pump passages or pipelines blocked
- Excessive wear of wear rings or sealing components
- Insufficient rotational speed
Recommended solutions:
- Clean the pump casing, impeller passages, and pipelines
- Replace worn wear rings or other damaged parts
- Increase pump shaft speed to the specified value
5. Pump Power Consumption Is Excessive
Possible causes:
- Packing gland tightened too much, causing stuffing box overheating
- Impeller wear leading to reduced hydraulic efficiency
- Pump operating at an excessive flow rate
Recommended solutions:
- Loosen the packing gland to an appropriate level
- Replace the worn impeller
- Increase discharge pipeline resistance or partially close the valve to reduce flow
6. Abnormal Internal Noise and Pump Does Not Deliver Liquid
Possible causes:
- Flow rate too high, causing excessive losses in the suction pipeline
- Air ingress at the suction side
- Pumped liquid temperature too high, reducing available NPSH and inducing cavitation
Recommended solutions:
- Increase resistance on the discharge side to reduce flow rate
- Inspect the pump suction pipeline for leaks or damage
- Check the foot valve, reduce suction lift, seal all air leakage points, and lower suction vacuum as needed
7. Pump Vibration
Possible causes:
- Misalignment between pump shaft and motor shaft
- Pump shaft bent or not installed in a straight line
Recommended solutions:
- Realign the pump and motor so that their shaft centerlines coincide
8. Bearing Overheating
Possible causes:
- Insufficient or missing lubrication oil
- Misalignment between pump and motor shafts
Recommended solutions:
- Add appropriate lubrication oil
- Align the shaft centerlines and inspect or clean the bearing housing
Conclusion
Recognizing typical pump fault symptoms and their root causes enables timely corrective action and helps prevent serious failures. Regular inspection, proper alignment, correct priming, and adequate lubrication are essential to maintaining reliable pump performance. For persistent or complex issues, consult the pump manufacturer or a qualified service provider.