First, start the process. 1 In the closed position, the ball is pressed against the seat by the [wiki] mechanical [/wiki] pressure of the stem. 2 When the handwheel is turned counterclockwise, the valve stem moves in reverse, and its bottom angular plane causes the ball to release from the seat. 3 The valve stem continues to lift and interact with the guide pin in the spiral groove of the valve stem so that the ball begins to rotate without friction. 4 Until the full open position is reached, the stem is raised to the limit position, and the ball is rotated to the full open position.

2. Closing process. 1 When closed, turn the handwheel clockwise, the stem begins to drop and the ball begins to rotate away from the seat. 2 Continue to rotate the handwheel, the valve stem is subject to the action of the guide pin embedded in its upper spiral groove, so that the valve stem and the ball rotate 90° at the same time. 3 When close, the ball has rotated 90° without contact with the seat. 4 For the last few turns of the handwheel, the angular plane at the bottom of the valve stem mechanically wedges towards the compression ball so that it is pressed tightly against the seat to achieve a complete seal.

1, the fluid resistance is small, and the resistance coefficient is equal to the pipe segment of the same length.

2, simple structure, small size, light weight.

3, tight and reliable, the sealing surface material of the ball valve is widely used in plastic, good sealing, and has been widely used in the vacuum system.

4, easy to operate, open and close quickly, from full open to full close as long as the rotation of 90 degrees, easy to remote control.

5, easy maintenance, ball valve structure is simple, the sealing ring is generally active, disassembly and replacement are more convenient.

6, when fully open or fully closed, the sealing surface of the ball and the seat is isolated from the medium, and the medium will not cause the erosion of the valve sealing surface.

7, wide range of application, small diameter to a few millimeters, large to a few meters, from high vacuum to high pressure can be applied. When the ball is rotated 90 degrees, the inlet and outlet should all be spherical, thus cutting off the flow.