Is Insufficient NPSH Available Always the Cause of Cavitation in Centrifugal Pumps?

Cavitation is often linked to the inability of the system to provide sufficient NPSH to the pump. Pump users often feel safe running a pump if the NPSH required by the pump is below what is available in the system. What is gas entrainment within process fluid and how does it affect pump performance? Is there a connection of entrained gas with cavitation? When flow through the pump is too low, a part of the mechanical energy that is put in for running the pump is converted to pressure energy and the remaining goes to heat the liquid. This raises the liquid temperature and eventually vaporizes it. This vapor stays within the process liquid as bubbles, which causes cavitation. All the above conditions cause cavitation. This paper describes how these conditions develop, and shows how to identify and then rectify them.