What is the effect of cavitation in pumps?
Cavitation causes pump performance deterioration, mechanical damage, noise and vibration which can ultimately lead to pump failure. Vibration is a common symptom of cavitation, and many times the first sign of an issue. Vibration causes problems for many pump components, including the shaft, bearings and seals.
What are the effects of cavitation on a centrifugal pump?
Cavitation in a centrifugal pump has a significant effect on pump performance. Cavitation degrades the performance of a pump, resulting in a fluctuating flow rate and discharge pressure. Cavitation can also be destructive to pumps internal components.
How does cavitation affect efficiency?
A large amount of cavitation will always reduce the head and the power of the pump as the vapor bubbles will reduce the active impeller passage. In rare cases this effect can even improve the pump efficiency; this can be confusing or misleading in trouble-shooting a situation which began with damage being observed.
What are the steps that can avoid the effect of cavitation in pump?
Some tips to prevent cavitation due to vaporization include:
- NPSHa > NPSHr + 3 ft or more safety margin.
- Lower temperature.
- Raise liquid level in suction vessel.
- Change out pump type.
- Reduce motor RPM.
- Use impeller inducer.
- Increase diameter of the eye of impeller.
What is cavitation and effects of cavitation?
Cavitation usually the result of rapid changes of pressure of the liquid. The cavitation cause erosion of surface as well as noise and vibrations. The cavitation occurs in pumps, orifice, venturi meter, control valves, impellers, etc. Eventually forms cavities on the boundaries (that is why it is called cavitation).
Why cavitation will occur in centrifugal pumps why not in displacement pumps?
In centrifugal pumps the eye of the pump impeller is smaller than the flow area of pipe. This decrease in flow area of pump results in increase in flow rate. So pressure drop happened between pump suction and the vanes of the impeller. This air bubbles are transmitted to pump which forms cavitation.