What is Cavitation?
What is cavitation and how does it occur?
Cavitation is the formation and destruction of water vapor bubbles in a boiling liquid as it moves through the pump. It often arises at the suction side of the pump, because here the inlet pressure is reduced.
It occurs when the inlet pressure in a pump is lower than the vapor pressure of the liquid, this phenomenon occurs when a pump is insufficiently filled. Causes of this are a too small inlet pipe, too low pressure in the inlet vessel, too high speeds or too high a vapor pressure.
Consequences of cavitation
The imploding vapor bubbles cause noise and vibrations which are followed by mechanical shocks.
Cavitation will damage the impeller, bearings and pump housing and has a very adverse effect on the life of a pump and associated components. Cavitation should be prevented or resolved to avoid high overhaul and replacement costs.
How can cavitation be prevented?
Cavitation can be prevented by keeping the pre-pressure (NPSHa) of the pump higher than the vapor pressure (NPSHr) of the pump. The NPSHa value must be at least 1 mWk higher than the NPSHr value.
To ensure this, it is very important that the correct pump is selected for the expected operating conditions. We assure you of correct and optimal pump selection with our team of experienced pump specialists.
Why is cavitation prevention crucial?
Once cavitation has been diagnosed, there are a number of ways to correct the problem. This includes lowering the temperature of the medium, lowering the volume flow or lowering the speed. These possibilities often lead to undesirable changes, such as a reduction in capacity and head.
If these options are applied but the noise and vibration persist, in many cases impeller or bearing damage has already occurred. In this case, these parts must be replaced, which entails unnecessary costs.
+31 (0)546 45 80 72
Available between 08:15 and 17:00
Available 24/7 for calamities
Address Twentepoort Oost 25, 7609RG Almelo