Cavitation in an agricultural centrifugal irrigation pump occurs when the local static pressure at the impeller eye falls below:
Options:
(A) The saturation vapor pressure of water at the operating temperature
(B) Atmospheric pressure
(C) Zero absolute gauge pressure
(D) Discharge pipe head
Answer Key:
A
Step-by-Step Solution & Explanation
When local liquid pressure drops below saturation vapor pressure ($p_v$), vapor bubbles form and subsequently collapse violently against the impeller vanes in higher pressure regions, causing severe pitting, noise, and vibration.