In order to reduce the operating torque of the ball valve and increase the reliability of the seal, oil seal ball valves have appeared in recent years, and the special lubricating oil is injected between the sealing faces to form an oil film, which enhances the sealing performance and reduces the operating torque. It is more suitable for high pressure and large diameter ball valves.
Elastic ball valve
The ball of the ball valve is elastic. Both the ball and the seat ring are made of metal material, and the sealing pressure is very large. The pressure of the medium itself cannot meet the sealing requirements, and an external force must be applied. This valve is suitable for high temperature and high pressure media.
The elastic sphere is made by opening an elastic groove at the lower end of the inner wall of the sphere to obtain elasticity. When the passage is closed, the wedge of the valve stem is used to open the ball and press against the seat to seal. Before the ball is rotated, the wedge head is loosened, and the ball is restored to its original shape, so that a small gap occurs between the ball and the valve seat, which can reduce the friction and operating torque of the sealing surface.
Ball valves can be divided into straight-through, three-way and right-angle types according to their channel positions. The latter two ball valves are used to distribute the medium and change the direction of the medium.