Patent ID: 7243900

Claim:
A ball valve, comprising: a valve body; a valve seat attached to said valve body by a screw thread; a valve ball accommodated within said valve body; first and second plastic sealing elements disposed respectively on opposite sides of said valve ball; a valve rod connected to said valve ball; and a valve cap on said valve rod, wherein said first sealing element is provided with a spring assembly on an outside thereof, the spring assembly including at least two springs with ladder-shaped longitudinal sections which are reverse-superimposed, wherein an inside of said first sealing element fits with a surface of said valve ball, while an outside of said first sealing element includes a supporting surface and an acting surface against which said spring assembly presses, wherein a periphery of said supporting surface forms an inclined cone-shaped surface in a direction of said valve seat, while said acting surface forms a vertical plane relative to a flow line, and wherein said second sealing element is disposed between said valve ball and said valve body, said ball valve further comprising: one ring metal gasket on each end of said spring assembly in order to support the spring assembly.