Connect the bottom flange of the gear operator to the upper flange of the valve and slide the valve shaft into the hole on the worm gear. Tighten the flange bolt. The valve can be closed by turning the hand-wheel clockwise and opened by turning the hand-wheel counterclockwise. On the upper face of the gear operator, a position indicator and a position marking are mounted, through which the position of switch can be directly observed. The gear operator is also equipped with a mechanical limit screw, which can be adjusted and function to limit the position at the switch extreme position.