ABSTRACT
The definition describes all conditions in a centrifugal pump from the growth and collapse of small bubbles in the pumped liquid to the occurrence of large amounts of vapour that are sufficient to vapour lock a pump in a predominantly liquid-filled system. The potentially serious consequences that can arise when a centrifugal pump cavitates are loss of economic performance, damage to expensive equipment, and, in the extreme, loss of life. Whilst a modest amount of cavitation may have no measurable effect, a large volume of cavities can result in the generated head being reduced considerably. In a centrifugal pump the local pressure drops experienced by the liquid flowing within its passages determine where cavitation occurs. The consequences of vapour locking are unacceptable. Many pumps, especially multistage pumps, incorporate internal clearances such as neck rings, interstage bushes, or balance drums, which act as pumped-liquid lubricated bearings.
