| 摘要 |
<p>The disclosure is directed to a high performance, leak tight seal for use primarily in butterfly control valves. In accordance with a significant feature of the invention, the seal is arranged and configured whereby fluid pressure within the butterfly valve environment is retained by the seal through three clearly defined, discrete pressure range operating stages. The seal is mounted within a seal containment chamber formed in the valve housing. The fluid pressure inherently and automatically orients the seal relative to the seal containment chamber to provide a seal geometry, containment chamber support, stress distribution and seal deflection which is optimum for the pressure range of the particular operating mode. The basic operating principle embodied in the seal of the invention provides for a re-orientation of the seal relative to the seal confinement chamber due to pressure effects upon the seal, whereby the seal retention point is moved inwardly toward the sealing surface in the successive higher pressure operating modes. In this manner, the pressure effects upon the seal are maintained at a practicable minimum to considerably reduce wear and tear on the seal and thereby greatly extend the worklife thereof.</p> |
