Patent ID: 8636021

Claim:
A method for determining the state of a valve assembly, the valve assembly including a stem cap with opened and closed positions relative to a valve seat, the stem cap being movable between the opened and closed positions by way of a motor, the motor rotating and drawing a current when operated, the valve assembly including a spring biased and conically shaped shuttle that is positioned within a stem cap passage within the stem cap, the shuttle having opened and closed positions, the method comprising the following steps: sending a signal to verify the initial position of the stem cap, the signal actuating the motor to move the stem cap into the closed position; monitoring the current draw of the motor and determining whether the current draw is high or low, with a high current draw reflecting an initially closed position and a low current draw reflecting an initially opened position; signaling either the initially closed or the initially opened position of the stem cap; sending a signal to close the stem cap when the stem cap is in the initially opened position, the signal activating the motor to move the stem cap into the closed position; monitoring the current draw of the motor and stopping the motor when the current draw reaches a pre-determined threshold, the pre-determined threshold reflecting the closed state; signaling the closed state of the stem cap; relieving any back pressure when the stem cap is in the closed position by opening the conically shaped shuttle against the spring bias.