Operation:

Several centrifugal pumps are designed in a manner which permits the pump to operate continuously for months or even years. Those centrifugal pumps frequently rely on the liquid in which they are pumping to give cooling and lubrication to the pump bearings and other internal components of the pump.  The pump will no longer be adequately cooled and the pump could quickly become damaged if flow through the pump is stopped although the pump is still operating. Pump damage could also result from pumping a liquid whose temperature is close to saturated conditions.