• There is a possibility of the liquid
pressure in liquid-flow systems
dropping below the vapor
pressure at some locations, and
the resulting unplanned
vaporization.
• The vapor bubbles (called
cavitation bubbles since they
form “cavities” in the liquid)
collapse as they are swept away
from the low-pressure regions,
generating highly destructive,
extremely high-pressure waves.
• This phenomenon, which is a
common cause for drop in
performance and even the
erosion of impeller blades, is
called cavitation, and it is an
important consideration in the
design of hydraulic turbines and
pumps.