The ball valve can be divided according to the structure

1. Floating ball ball valve The ball of the ball valve is floating. Under the action of the medium pressure, the ball can make a certain displacement and press tightly on the dense book cover at the inlet end to ensure the seal at the inlet end. The structure of the floating ball valve is easy and the sealing is good, but the load of the ball accepting the task medium is fully transmitted to the inlet gasket, so it is necessary to consider whether the gasket material can withstand the task load of the ball medium. This structure is widely used for medium and high pressure ball valves.



2. Flowing ball ball valve The ball of the ball valve is flowing and does not move after being pressurized. The flow ball valve has a floating valve seat. After receiving the pressure of the medium, the valve seat moves to make the gasket press tightly on the ball to ensure the seal. Generally, the upper and lower shafts of the ball are equipped with bearings, and the operating torque is small, which is suitable for low-pressure and large-diameter valves. In order to reduce the operating torque of the ball valve and increase the level of reliability of the seal, oil-sealed ball valves have emerged in recent years. Special smooth oil is injected between the secret book covers to form a layer of oil film, which strengthens the sealing performance and reduces the operating torque. , More practical low-pressure large-caliber ball valve.



3. Inertial ball valve The ball of the ball valve is inertial. Both the ball and the seat gasket are made of metal materials, and the specific pressure of the seal is very large. The pressure of the medium itself has reached the request of the absence of the seal, and external force must be imposed. This kind of valve is suitable for low temperature and low pressure medium. The inertial sphere is to open an inertial groove at the lower end of the inner wall of the sphere and lose its inertia. When opening the channel, use the wedge-shaped head of the valve stem to expand the ball and press the valve seat to seal. When the ball is being rotated, first grasp the wedge-shaped head first, and then the ball will return to its embryonic shape, so that a small gap appears between the ball and the valve seat, which can reduce the conflict and operating torque of the dense book cover.