Pneumatic eccentric eccentric half ball half ball and belong to the same type of valve, the difference between its power source, an eccentric semi-ball is a sphere rotating around the center line the body achieve open and close a valve. Valve in the pipeline is mainly used for cutting, distribution and change the direction of media flow. Two-piece ball valve, three-valve, is a new valve has been widely used in recent years, semi-pneumatic valve also increasingly been used to various industries. Pneumatic eccentric semi-ball Profile is the use of power-driven ball valve. Fluid resistance, the pipe resistance coefficient equal to the same length. Simple structure, small size and light weight. Close and reliable valve sealing surface material widely used plastic, sealing, have been widely used in the vacuum system. Easy to operate, opening and closing rapidly, from fully open to fully closed as long as the rotation 90 °, to facilitate remote control. Easy maintenance, simple ball valve, seals are generally activities, the removal replacement is more convenient. In the fully open or fully closed, sealing surface and the dielectric isolation ball and seat, through the media, will not cause erosion of the valve sealing surface. Wide range of applications, from small to a few millimeters in diameter, large meters, from high vacuum to high pressure can be applied. It works by the rotary valve chain to the valve flow or occlusion. Valve switch light, small size, can be made into a large caliber, reliable sealing, simple structure, easy maintenance, with the spherical sealing surface often in the closed state, the media can not easily be eroded, in various sectors has been widely used.