Three type ball valve operation, you know?

Three type ball valve opening process: in the closed position, sphere subjected to mechanical pressure of the stem, press the seat; When turn the handwheel counterclockwise, the valve stem is reverse movement, the Angle at the bottom of the plane makes the ball off the seat; Stem continue to ascend, and valve stem guide pin of interaction in the spiral groove, sphere began without some friction spinning; Until to the fully open position, the valve stem to limit position, sphere rotation to the full open position. The shutdown process: closing, rotating the handwheel clockwise, stem began to drop and the ball left seat begin to spin; Continue to rotate the handwheel, the valve stem is embedded in the spiral groove on the role of the guide pin, make the stem and ball rotation 90; at the same time Is closed, a sphere has been without contact with the valve seat rotated 90 & deg; ； Hand wheel rotation of the last few laps, stem mechanically wedge Angle at the bottom of the plane to the oppression of a sphere, make its strong pressure on the seat, to completely seal.