... -PW-shaft power K1, K2, and K3-constant as shown in the following picture:As shown ... K * P * Q Where K is a constant, through the valve orifice Q / 2, in this case, the shaft ... Q / 2 = 0.5PW Adopted frequency control, the valve is fully open, the pump outlet pressure is: (1/ ... such as multi-pump operation, fault switching, constant voltage constant water level can properly achieved.Technical parameters ...