Mechanical seals and Pumps

How to Remove Airlock in Centrifugal Pump

Have you ever encountered an airlock in your centrifugal pump? This frustrating issue can cause your pump to lose prime and stop working efficiently. In this blog post, we’ll guide you through the steps to quickly identify and remove an airlock from your centrifugal pump, ensuring your system operates smoothly and reliably. Learn how to get your pump back in action today! 64f42d03e0bb1

Step 1. Shut off the power supply

Locate the main power switch for the centrifugal pump. Turn the switch to the “OFF” position to ensure safety during the airlock removal process.

Step 2. Close the suction and discharge valves

Identify the suction and discharge valves connected to the centrifugal pump. Turn the valve handles clockwise to close both valves completely. This prevents water from entering or leaving the pump during the airlock removal procedure.

Step 3. Open the air vent or priming plug

Find the air vent or priming plug on the top of the centrifugal pump casing. Use an appropriate wrench or tool to carefully loosen and remove the air vent or priming plug. This allows trapped air to escape from the pump system.

Step 4. Fill the pump with water

Slowly pour clean water into the pump casing through the open air vent or priming plug. Continue filling until water begins to overflow from the opening, indicating that the pump is fully primed.

Step 5. Reinstall the air vent or priming plug

Once the pump is filled with water, carefully thread the air vent or priming plug back into its original position.

Step 6. Open the suction and discharge valves

Turn the valve handles counterclockwise to open both the suction and discharge valves. This allows water to flow through the pump system once again.

Step 7. Restore power and start the pump

Return to the main power switch and turn it to the “ON” position. Observe the centrifugal pump as it begins to operate.

Check for any leaks or unusual noises, which may indicate additional issues that require attention.

Step 8. Monitor the pump’s performance

Allow the centrifugal pump to run for several minutes while closely monitoring its performance. Verify that the pump is delivering water at the expected flow rate and pressure.


What is an airlock in a centrifugal pump?

An airlock occurs when air gets trapped in the pump, preventing it from generating proper suction and flow.

What are the symptoms of an airlock?

Symptoms include poor suction, reduced flow, and the pump running but not moving fluid effectively.

Can airlock cause damage to the pump?

Yes, prolonged airlock can lead to cavitation, which can damage the impeller and other components.

Is it safe to open the pump casing while it’s running?

No, always turn off the pump and ensure it’s completely stopped before opening the casing.

In conclusion

Following these steps will help remove airlock in a centrifugal pump and restore its proper function. Remember to always prioritize safety and consult the pump’s manual for specific instructions. If the issue persists, consider contacting a professional for assistance to ensure the pump’s optimal performance.


Todd is the manager of Cowseal mechanical seal manufacturer. Cowseal located in China with over 20 years of experience in the mechanical seal and pump industry. They offer a wide range of high-quality mechanical seals and are committed to providing reliable and cost-effective solutions for their customers.

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