Fixed ball valve opening and closing process

The fixed ball valve is equipped with a floating valve seat. After the medium pressure, the valve seat moves and the sealing ring is pressed against the ball to ensure the sealing. Bearings are usually mounted on the upper and lower shafts of the ball, and the operating torque is small, suitable for high pressure and large diameter valves.

The fixed ball valve is equipped with a floating valve seat. After the medium pressure, the valve seat moves and the sealing ring is pressed against the ball to ensure the sealing. Bearings are usually mounted on the upper and lower shafts of the ball, and the operating torque is small, suitable for high pressure and large diameter valves. In order to reduce the operating torque of the ball valve and increase the reliability of the seal, oil seal ball valves have appeared in recent years. Special lubricants are injected between the sealing surfaces to form a layer of oil film, which enhances the sealing performance and reduces the operating torque. , It is more suitable for high pressure and large diameter ball valve.

First, open the process

1. In the closed position, the ball is mechanically pressed by the valve stem and pressed against the valve seat.

2. When the handwheel is turned counterclockwise, the valve stem moves in the opposite direction, and the bottom angular plane releases the ball from the valve seat. 3. 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. 4. Until the fully open position, the stem is raised to the extreme position and the sphere rotates to the fully open position.

Second, close the process

1. When closed, rotate the handwheel clockwise and the stem begins to lower and the ball moves away from the seat.

2, continue to rotate the hand wheel, the stem is embedded in the guide groove on the spiral groove, so that the valve stem and the ball simultaneously rotate 90 °.

3. When the ball is about to close, the ball has rotated 90° without contact with the valve seat.

4. In the last few rotations of the handwheel, the angular plane at the bottom of the valve stem is mechanically wedged against the ball so that it presses tightly against the valve seat to achieve complete sealing.