A method and system for controlling a flow control valve, comprising measuring a flow at a suitable point of a flow process and calculating a pressure drop across the valve from a Cv curve of the valve, a measured valve opening αm, and the measured flow (Qm). From this calculated pressure drop, a flow set point (Qsp), and an inverse Cv curve of the valve, a new valve opening (αc) providing the desired flow is calculated. The control is thus adapted to each operating point and its prevailing flow gain and linearizes the dependence between flow control and flow.