The opening and closing parts of the pneumatic globe valve are plug-shaped valve flaps with a flat or tapered sealing surface, and the valve flaps move in a straight line along the centre line of the fluid. The movement of the valve stem is in the form of a lifting stem (the stem is lifted, the handwheel is not lifted) or a lifting and rotating stem (the handwheel is rotated and lifted together with the stem and the nut is located on the valve body). The stop valve is only suitable for full opening and full closing, not allowed for regulation and throttling