Ball valve  form of the structure can be divided into:

1.Floating ball valve:

Valve ball is floating, the medium under pressure to produce a certain displacement sphere and pressed against the sealing surface of the outlet end, the outlet end to ensure sealing.Shown in Figure:

Floating ball valve simple structure, good sealing.But the media sphere to work under all loads to pass the exit ring, so to consider the ring material can withstand the work load of the media sphere. This structure is widely used in the low-pressure valve.

2.Fixed ball valve

The ball valve is fixed, the pressure does not produce movement. Fixed ball valve comes with floating seat, by the media pressure, the valve seat movement, so that seals pressed on the sphere, in order to ensure sealing. Generally with the ball on the lower shaft with bearings, operating torque, suitable for high pressure and large diameter of the valve. Shown in Figure . 

To reduce the valve operating torque and increasing the reliability of the seal, valve seals has emerged in recent years, both in the sealing surface pressure injection of a special lubricant to form a layer of film that enhances the seal, but also reduce operating torque , more suitable for large-diameter high-pressure valve.

3.Elastic ball valve

The ball valve is elastic. Ball and seat rings are metal materials, sealing pressure than the large, rely on the media itself is less than the pressure reached sealing requirements must apply force. This valve is suitable for high temperature and pressure media. Shown in Figure 

Elastic sphere is the lower end of the inner wall of the sphere to open an elastic groove, and access flexibility. When closing the channel, the wedge-shaped head with the stem to open up the ball and seat clamp to seal. Loosen before turning the ball wedge-shaped head, the ball followed to restore the original prototype, the sphere and the small gap between the valve seat can reduce the sealing surface of the friction and operating torque.

Ball valves can be divided according to their straight-channel position, tee and right angle. The latter two ball valves for dispensing media and change the flow of media.

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