Centrifugal pumps are widely used in various industries for its high efficiency and easy operation. However, sometimes it may experience a phenomenon called cavitation, which affects the pump performance and even causes damage to the pump parts.
Cavitation happens when the pump intake pressure drops below the vapor pressure of the liquid, causing the liquid to vaporize and form bubbles. These bubbles will implode when they reach higher pressure zones, creating shock waves that erode the impeller and other pump components.
The reasons for centrifugal pump cavitation can be summarized as follows:
1. High suction lift or pressure drop in the suction line: When the suction lift or pressure drop is too high, the pump cannot maintain the required NPSH (Net Positive Suction Head), which is the difference between the suction pressure and the vapor pressure of the liquid. As a result, the liquid boils and cavitation occurs.
2. Clogged suction strainer or filter: If the suction strainer or filter is clogged, it will reduce the suction flow rate and increase the pressure drop. This will lead to a decrease in the NPSH available and cavitation.
3. Viscous or abrasive fluid: Viscous or abrasive fluids can cause damage to the impeller and increase the risk of cavitation. This is because the impeller cannot handle the high shear stresses generated by these fluids, which can cause erosion and wear.
To prevent and troubleshoot pump cavitation, the following measures can be taken:
1. Increase the suction pressure or reduce the suction lift: This can be achieved by increasing the diameter of the suction pipe, reducing the length of the suction line, or increasing the liquid level in the suction tank.
2. Clean or replace the suction strainer or filter: Regular maintenance of the suction strainer or filter will prevent clogging and ensure smooth flow of the pump.
3. Use a fluid with appropriate viscosity and avoid abrasive materials: Selecting the right fluid for the pump application can prevent damage to the pump and reduce the risk of cavitation.
In conclusion, centrifugal pump cavitation can be prevented and troubleshooting by taking the necessary measures to maintain the required NPSH and ensure smooth flow of the pump. By doing so, the pump can operate efficiently and reliably, contributing to the success of the industry.
