| 摘要 |
<p>A valve for opening and closing a fluid conduit of the type having a generally wide cross section, the conduit having a transverse slit therein to allow for movement of a shut-off plate therethrough. The shut-off plate has a spherical shape and defines a center about which the shut-off plate may be arcuately displaced to close the conduit when the plate is positioned within the conduit and to open the conduit when the plate is positioned external to the conduit.</p> |
