@husker posted:David, I have to disagree with your statement "cavitation creates air bubbles". Cavitation is the formation and subsequence collapse of VAPOR bubbles as a fluid flows from the low pressure in the eye of the impellor where the bubbles form, along the vanes where the pressure increases and the bubbles collapse, to the volute. The bubbles collapsing can impart thousands of pounds of pressure (depending on the system) which causes the noise and damage to the vanes.
I’m only relaying what I was told by Stewart but perhaps I misunderstood the “air bubbles” issue. I will defer to you on this one!