The present application provides a method of evaluating fatigue damage in an actuator spring of a valve used in a turbine by a data acquisition system. The method may include the steps of receiving a number of operating parameters from a number of sensors including valve spindle position over time, determining cyclic loading on the actuator spring based upon the valve spindle position over time, generating an intended design lifetime for the actuator spring, determining a fatigue damage indicator based on the cyclic loading as compared to the intended design lifetime, and altering one or more of the operating parameters and/or initiating repair procedures based upon the fatigue damage indicator.