... to the characteristic of the parallel operation curve, the result of the second optimization can not be accordance with the requirement of the first completely. If the outlet pressure of ... - Q-H Curve of the Variable Speed Pump In figure 1, a is the Q-H curve of which the pump runs with the rated speed n0, b is the Q-H curve of which the pump runs at the speed of n1, n1=0.75n0, ... Because of the limitations of speed control devices and characteristic of pumps, there are different speed ranges for pumps of variable types, generally 0.75~1.0 of the rated speed, no matter what...