1. Opening process:
A. In the closed position, the ball is pressed against the valve seat by the mechanical pressure of the valve stem;
B. When the handwheel is turned counterclockwise, the valve stem moves in the opposite direction, and the angular plane at the bottom makes the ball free from the valve seat;
C. The valve stem continues to lift and interacts with the guide pin in the spiral groove of the valve stem, so that the ball begins to rotate without friction;
D. Until it reaches the fully open position, the valve stem is raised to the limit position, and the ball rotates to the fully open position.
2. Closing process:
A. When closing, turn the handwheel clockwise, the valve stem begins to drop and the ball leaves the valve seat to start rotating;
B. Continue to rotate the handwheel, and the valve stem will be actuated by the guide pin embedded in the spiral groove on it, so that the valve stem and the ball can rotate 90° at the same time;
C. When it is about to close, the ball has rotated 90° without contact with the valve seat;
D. In the last few turns of the handwheel, the angular plane at the bottom of the valve stem mechanically wedges and presses the ball to make it tightly press on the valve seat to achieve a complete seal.
Post time: Sep-02-2024