Ball valve and gate valve are the same type of valve, the difference is that its closing part is a ball, the ball is rotated around the body core line to achieve the opening and closing of a valve. Ball valves are mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. Flange ball valve standard GB/T21465-2008 "Valve terminology" is defined as: the opening and closing parts (spheres) are driven by the valve stem and rotate around the axis of the valve stem.
Opening procedure
1. In the closed position, the ball is pressed against the seat by the mechanical pressure of the valve stem.
2. When the handwheel is turned counterclockwise, the valve stem moves in reverse, and its bottom angular plane makes the ball free 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 it reaches the full open position, the valve stem is raised to the limit position, and the ball is rotated to the full open position.
