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.
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.
