Pump operation, due to changes in external loads and require changes in conditions, the man-made way to change the pump operating point is called regulation. Pump condition point regulation is the flow regulation, and the size of the pump flow depends on the location of the pump work point, therefore, pump condition adjustment is the work point position. There are usually the following methods, one is to change the pump performance curve; the second is to change the pump line characteristic curve; the third is the two curves change at the same time.