Generally speaking, the ball valve working mechanism works this way. Whether it is manually or actuator operated, some force moves the lever or handle to a quarter turn to open the valve. This force is transferred to the stem, moving the disc to open.
The ball disc turns and its hollowed side faces the flow of media. At this point, the lever is in the perpendicular position and the port to parallel in relation to the flow of media. There is a handle stop near the connection between the stem and bonnet to only allow a quarter-turn.
To close the valve, the lever moves back a quarter turn. The stem moves to turn the ball disc in the opposite direction, blocking the flow of media. The lever is in the parallel position and the port, perpendicular.
Lastly, the rising stem ball valve utilizes the tilt-and-turn mechanism. The ball disc wedges to the seat when the valve closes. When it opens, the disc tilts to remove itself from the seat and allow media flow.
