CENTRIFUGAL PUMP CAVITATION:
During operation, if the pressure in the suction side falls below the vapour pressure of the liquid being pumped at that temperature, then vapour will be formed. The phenomenon is likely to occur if there is a restriction in the suction pipe, if the liquid is volatile or has a higher temperature than anticipated, or if the impeller speed is excessive. A vapour cavity of this form likely to cause loss of suction or erratic operation. The vapour bubble created would collapse in an area of higher pressure and cause cavitation damage. A change of flow direction from axial to radial causes the fluid to experience different velocities and at the extremity, a drop is pressure could produce cavitation again with subsequent bubble collapse and damage. Cavitation could cause surface roughening and generate some tell - tale wise.
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