Author:Site Editor Publish Time: 2018-11-17 Origin:Site
The ball valve is mainly used to cut off the flow, distribute the flow rate and change the flow direction. It can rotate at 90 degrees. Ball valves have many functions, and they can also be used as switches. The ball valve is mainly used in the pipeline to cut, distribute and change the flow direction of the medium. It only needs to be rotated 90 degrees and the torque can be closed tightly.
The ball of the ball valve is floating. Under the action of the medium pressure, the ball can generate a certain displacement and press against the sealing surface at the outlet end to ensure the sealing of the outlet end. The floating ball valve has a simple structure and good sealing performance, but the load of the ball subjected to the working medium is all transmitted to the outlet sealing ring, so it is necessary to consider whether the sealing ring material can withstand the working load of the spherical medium. This structure is widely used in medium and low pressure ball valves.
The ball of the ball valve is trunnion mounted and does not move after being pressed. After the medium pressure, the valve seat moves, so that the sealing ring is pressed against the ball to ensure the seal. Usually mounted on the upper and lower shafts of the ball, the operating torque is small, suitable for high pressure and large diameter valves. In order to reduce the operating torque of the ball valve and increase the availability of the seal, in recent years, an oil-sealed ball valve has appeared, which injects a special lubricating oil between the sealing faces to form an oil film, which enhances the sealing property and reduces the operating torque. It is more suitable for high pressure and large diameter ball valves.
3, elastic ball valve
The ball of the ball valve is elastic. Both the ball and the seat seal are made of metal material, and the sealing pressure is very large. According to the pressure of the medium itself, the sealing requirements are not met, 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.
high pressure ball valve, medium pressure ball valve, low pressure ball valve;
full bore ball valve, reduced bore ball valve;
straight-through, three-way, right-angle;
high temperature ball valve, normal temperature ball valve, low temperature ball valve, ultra low temperature ball valve;
soft seal ball valve, hard seal ball valve;
top-loading ball valve, side-mounted ball valve;
manual ball valve, automatic control ball valve (pneumatic ball valve, electric ball valve, hydraulic ball valve);
super large diameter ball valve, large diameter ball valve, medium caliber ball valve, small caliber ball valve.