Abstract: A mechanism used for locking a valve that provides positive control of the valve lock to prevent the valve from changing position unintentionally. The positive locking valve control device preferably comprises a push-pull rod having a toothed configuration that is engaged at different positions by a spring mechanism on the valve locking device in order to hold the push-pull rod and thereby the valve securely in place. To adjust the opening of the valve, the push-pull rod can be rotated by some predefined amount (such as 90 degrees) clockwise or counter-clockwise. This rotation frees the locking spring on the valve locking device from the teeth aligning it with a side of the push-pull rod thereby permitting linear movement of the rod to cause a corresponding adjustment in valve position. The rod is then “pushed in” or “pulled out” to adjust the size of the valve opening until the desired flow through the valve is obtained.