Ball valve ball of elastic. Ball and seat seal rings are manufactured with metal, sealing pressure is greater, depending on pressure of the medium itself is not up to the sealing requirements must be met with force. This valve is suitable for high temperature and high pressure medium.
Elastic sphere within sphere opens a slot at the lower end of the wall, and gain flexibility. When the channel is closed, with stem wedge to make a sphere rolling out and valve seat pressure sealed. Sphere in the rotation before you release the wedge-shaped head, sphere with the restoration of the original prototype, so there is a small gap between the ball and seat can reduce the friction of the sealing surface and operating torque.