What is valve authority?
Information on Valve Authority to obtain good control.
Valve Authority = (Pressure drop across fully open control valve) / (pressure drop across the remainder of the circuit) + (pressure drop across fully open valve)
In other words, valve authority within a system indicates how much of the system's total pressure drop comes from the control valve. It is common practice to consider the range between .2 to .5 as "acceptable" authority for proportional valve.