What is Cavitation?

What is Cavitation and what does it do to your pump?

Cavitation is the vaporization and subsequent implosion of the liquid being pumped. These implosions release kinetic energy in the form of high pressure shock waves. These shock waves will cause impingement damages to the impeller and casing, vibration damage to the mechanical seal and bearings, and a reduction in the pump's efficiency and overall life span.

Please watch video showing cavitation inside a pump as it goes from light to severe.

Cavitation in terms of Net Positive Suction Head:  

Net Positive Suction Head (NPSH) is used to determine if the liquid being pumped will vaporize. If the Net Positive Suction Head Required (NPSHr) is more than the Net Positive Suction Head Available (NPSHa), cavitation will occur. 

NPSHr > NPSHa => Cavitation