Working Principle, Installation And Maintenance Of Manual Ball Valve

1. Working principle

1. Opening process

1) In the closed position, the ball is pressed against the valve seat by the mechanical pressure of the valve stem.

2) When the handwheel is turned counterclockwise, the valve stem moves in the opposite direction, and the angular plane at the bottom causes the ball to disengage from the valve seat.

3) The valve stem continues to rise and interacts with the guide pin in the spiral groove of the valve stem, causing the ball to begin to rotate without friction.

4) Until the fully open position, the valve stem rises to the limit position and the ball rotates to the fully open position.

2. Closing process

1) When closing, rotate the handwheel clockwise, the valve stem begins to descend and causes the ball to leave the valve seat and begin to rotate.

2) Continue to rotate the handwheel, and the valve stem is affected by the guide pin embedded in the spiral groove on it, causing the valve stem and the ball to rotate 90° at the same time.

3) When it is about to close, the ball has rotated 90° without contact with the valve seat.
4) In the last few turns of the handwheel, the angular plane at the bottom of the valve stem mechanically wedges and presses the ball, making it tightly pressed on the valve seat to achieve complete sealing.

2. Installation and maintenance

2 Piece Ball Valve can be divided into straight-through, three-way and right-angle types according to its channel position. The latter two types of ball valves are used to distribute media and change the flow direction of the media. The following matters should be noted when installing and maintaining the three-piece ball valve:

1. Leave space for the valve handle to rotate.

2. It cannot be used for throttling.

3 Ball valves with transmission mechanisms should be installed upright.