| 摘要 |
<p>A sealing sleeve for a gate valve is disclosed which is designed to respond to movements of the gate of the valve in a particular manner. The seal undergoes an axial compressive type movement as the gate is moved between opposed sealing sleeves and this causes a predetermined radially inward buckling of an intermediate wall section of the sealing sleeve. This predetermined buckling creates a spring bias in the sleeve, urging the sleeve to return to the original, less stressed condition. Preferably, the sleeve is of a composite structure and a particular component of the intermediate wall section creates this spring bias. This structure has improved operating characteristics and accommodates a wider range of resilient materials to be used for the sealing sleeve.</p> |
