What Is Pump Cavitation?
When bubbles and hollow spaces form in water or other liquids while it is being pumped, it is called pump cavitation. This can cause equipment failure in a water pump or a hydraulic pump. One sign that there is pump cavitation is that there is going to be a loud vibrating noise that can be heard. This is the signal that there is something wrong and that the pump needs to be cleared of these bubbles and hollow spaces.
There are five reasons why pump cavitation occurs:
#1 Vaporization – When there is too much heat on a liquid it turns to vapor. There are generally heads that keep this from happening. If these heads are damaged, then the temperature of the water can get too high and can create the vapor that causes pump cavitation. Another way that vaporization occurs is when the fluid levels are too low. This means the fluid can heat up quicker. It is important to maintain fluid levels so that they do not produce vaporization. This is very important in positive displacement pumps.
#2 Internal Recirculation – When the fluid circulates too fast, it can create vaporization of the fluids that then are brought to the top of the unit through the centrifugal force. Keeping the speed of the pump to a lower rotation can keep this from occurring. It is important that the rotation is set for the fluid so that it is not too fast or too slow.
#3 Disruption of Flow – When there are particles or other obstructions in the liquid that is being pumped. By keeping a consistent pump rate these obstructions are not going to be as noticeable. It is also important to keep the pipes cleaned and cleared of debris. Regular maintenance and vacuum pump oil can keep this problem at bay.
#4 Velocity Captivation – This is when the liquid is forced through a pipe that is too small. Making sure the pipes and hoses are the correct diameter before setting up the pump can keep this from happening. This is vital as a small hose and the wrong pressure can create a good deal of damage to the system. When a pipe gets too dirty and clogged, it can also create the same problem. By regularly maintaining the pipes and hoses, this is not going to be an issue.
#5 Air Ingestion – While this is not really cavitation, it does act in the same way and should be noted for reference. This is similar to vaporization but it is when there is a leak in a gasket that allows unwanted air to be pulled into the reservoir tank. This is going to cause a decrease in the volume.
If a vacuum pump is maintained regularly by using vacuum pump oil and other measures, then there is not going to much chance of pump cavitation. By keeping the pressure at a steady rate there is going to be less of a chance as well. It is also important to keep the lines free of debris the pump is going to work much smoother and there are going to be less chances of cavitation.
