Question

cavitation is caused by ?

A) High pressure

B) High viscosity

C) high what ???

what is the purpose of prime pumping ?

Answer 1

Cavitation is defined as the process of formation of the vapor phase of a liquid when it is subjected to re- duced pressures at constant ambient temperature. Thus, it is the process of boiling in a liquid as a result of pressure reduction rather than heat addition.

Cavitation generally occurs in a pump , when the fluid is flowing in a pump , there is maximum pressure drop at the eye of the impeller. If the pressure exerted at this point is less than the vapour pressure of the liquid flowing , boiling of the liquid happens.

So cavitation is not caused due to high pressure or high viscosity. The reason is because of LOW PRESSURE.

2. Purpose of prime pumping :

Priming is the process in which the impeller of a centrifugal pump will get fully submerged in a liquid without any air trap inside. Especially required during startup of a pump.

Air bubbles inside the pump can damage the impeller with collisions.

Priming is required when elevation of the liquid in the suction tank is less than the elevation of the pump.