Cavitation is a phenomena which involves the formation and subsequent collapse of vapor filled cavities in a liquid. If the total pressure of the liquid falls below the vapor pressure then the cavities are formed. During the dynamic action of the pumps energy is added to the fluid by the impeller, plunger, or rotor the pressure increases, causing the vapor cavities to collapse or implode. The forces created by the bubbles collapsing can be large enough to cause severe damage if the collapse occurs near a solid surface.
Exposure to cavitation can have the following effects on pumps:
- Reduced capacity due to the vapor present
- High vibration
- High noise caused by the implosions
- Pitting or cavitation erosion on the internal metal surfaces
- Losses in pump head and efficiency and erratic power consumption