Q340Y jacket type eccentric ball valve marked the ball valve technology has entered a new stage.One of the characteristics of opening and closing without friction, as a result of eccentric structure, the valve is in the process of closing, the sphere gradually close to the seat, to the fully closed position contact;In open left seal position of ball is completely off, open the torsion from small;Second sealing surface can be realized from the clean, sphere left seat, medium can sweep away the accumulation of the sealing surface, for easy crystallization medium, the ball can be removed in the process of closing sealing medium crystal to achieve, to avoid the disadvantages of the other cannot switch valve;The third characteristic is sealed, sphere, the seat is double metal, adopts the different process, the sealing surface can be combined into various types such as anti-corrosion, wear-resistant, meet the needs of different working conditions, sealing is spherical line contact, by two-dimensional eccentric.