How Do You Troubleshoot a Centrifugal Pump?

Centrifugal pumps are widely used in diverse industries, including oil and gas, chemical processing, water treatment, and more. They are used to move fluids through pipelines and equipment, but sometimes they do fail, leaving everyone scratching their heads. Fortunately, most pump issues are easy to resolve with a little troubleshooting. Knowing how to identify, diagnose, and resolve problems is instrumental in keeping your pump running smoothly. This blog post is a practical guide to troubleshooting centrifugal pumps. Let’s get started!

Common Issues to Troubleshoot

No or Low Flow

When a pump fails to move liquid or delivers an inadequate amount, the cause may be insufficient suction pressure or a blockage in the suction line. Check for any clogging in the inlet strainer or suction line that may be obstructing the flow. Inadequate suction pressure can result from a plugged or improperly sized suction line or a clogged impeller. It is essential to verify that the suction pipe is as straight as possible, has correct fittings, and that the suction valve is entirely open. Finally, confirm that your pump is correctly primed and the impeller is spinning in the right direction.

High Vibration

High vibration is a common sign of problems in the pump piping or motor. It could indicate that the pump isn't level and appropriately grouted, which could cause pipe strain. Ensure that the pump pipe supports can hold the weight of the pipes and that the foundation adequately supports both the bearings and the pump. Another possible explanation for high vibration levels is a loose motor, therefore it is essential to check if the motor bolts, coupling, and shaft alignment are correct.

Leaks

Centrifugal pumps can also experience leaks that can compromise their efficiency and contaminate the environment. Leaks can occur in various parts of the pump, including shaft seals, stuffing box cover, or casing. To resolve leaks in the shaft seal, check and ensure that the seal is correctly installed and the gland nuts are tightened to the recommended level. In case of stuffing box leaks, examine the packing rings and the shaft sleeve for wear, and replace them if required. Lastly, check that the casing cover fits securely and that the gasket is in good condition.

Excessive Noise

Loud, abnormal noise is another sign of centrifugal pump problems that require troubleshooting. It may signify various problems, including cavitation, loose components, or obstruction in the discharge line. To resolve cavitation, ensure that the NPSH (Net Positive Suction Head) is adequate and raise it if required. In case of loose components, check if the coupling is correctly aligned and if the motor bolts are tight. Make sure that the discharge line is free from any obstructions, restrictions, or valves that could restrict the flow.

Impeller Issues

Pumps often experience impeller issues such as erosion, corrosion, or cavitation, which can affect their performance. When the impeller wears, it affects the pump's flow rate and can lead to other problems. To resolve impeller issues, ensure that the impeller is correctly installed, the clearances are as per the manufacturer's recommendations, and the vanes are well polished. Cavitation can cause impeller damage, and it is advisable to maintain the NPSH level to avoid it.

Overheating

Overheating can occur if the pump is operating beyond its capacity, or if there is inadequate cooling. Start by checking the motor and bearings for any damage or wear. If these parts are damaged, you'll need to replace them. Another cause for overheating is insufficient lubrication. Check the lubrication system and ensure that it is adequately lubricating the components.

Conclusion

In conclusion, troubleshooting centrifugal pumps does not have to be a daunting task. A pump that is correctly installed, maintained, and serviced can provide years of reliable and efficient service. Knowing how to diagnose and resolve pump problems can keep your operation running smoothly and help you avoid costly downtime or equipment replacement. Many pump issues are minor and easy to fix, and by maintaining pump performance, you can avoid costly and unnecessary downtime. We hope these tips prove helpful in troubleshooting your centrifugal pumps.

For help troubleshooting your industrial pumps or general pump repair and maintenance, give HISCO Pump a call at 800-236-6930.