Cavitation occurs when cavities or bubbles form in the liquid being pumped; a process which will directly affect capacity, head pressure and efficiency.
The cavities (bubbles) will also collapse within the higher pressure areas and cause noise, vibration and mechanical damage to components.
This damage was caused by imploding air bubbles
Pump cavitation is an audible implosion of the gas bubbles due to suction pressure differences within the pump.
The five basic reasons for cavitation are:
Vaporisation – fluid vaporises when its pressure becomes too low, or its temperature is too high.
Air ingestion – a centrifugal pump can handle 0.5% air by volume. At 6% air the results can be disastrous. Air must be removed from the system using AAV’s etc.
Internal recirculation – as the name implies, the fluid recirculates increasing its velocity until it vaporises and then collapses in the surrounding higher pressure.
Flow turbulence – corrosion or obstructions can change the velocity of this liquid, and any time you change the velocity of a liquid, you change its pressure.
Vane passing syndrome – this type of cavitation damage is caused when the OD of the impeller passes too close to the pump cutwater.
_____________________________________________________
View our full site.
Back to the blog.
We’re on Google+
And Facebook!
ecexproblemsolved 