When the pressure falls below the vapour pressure of the liquid at a
given temperature, boiling occurs and small bubbles of vapour are
formed. These bubbles will grow in the low-pressure area and implode when they are transported to an area of pressure above vapour pressure.
The term given to this local vaporisation of the fluid is Cavitation.
Centrifugal Pumps - Cavitation
The collapsing of the bubbles is the area of Cavitation we are concerned with, as extremely high pressures are produced, which causes noise and erosion of the metal surface.
The area of pipeline where Cavitation mainly occurs is the pump suction, where the liquid is subjected to a rapid rise in velocity, and hence a fall in static pressure.
