Abstract: A mechanism used for locking a valve that provides positive control of the valve lock to prevent the valve from changing position unintentionally is disclosed. The positive locking valve control device preferably includes a housing with a handle and a linkage extending therefrom. A main gear inside the housing is disposed about a shaft which is positionally fixed outside of the housing. The main gear is releasably intermeshed with a locking gear controlled by the handle. Squeezing the handle separates the gear and allows angular movement of the handle which corresponds to movement of the linkage. The linkage is connected to a valve actuator or valve stem and the position of the valve may be adjusted in this manner. Springs in the handle cause the main gear and locking gear return to a locked position when the handle is released. Accordingly, the valve cannot drift or be bumped out of position when the handle is released.