| 摘要 |
<p>A riser-type transfer valve includes a diverter body, a diverter collar threaded onto the diverter body, a valve actuator mounted for axial reciprocal travel concentric with the diverter body and diverter collar, a valve mounted on the valve actuator at the base thereof for travel between a diverter body lower outlet valve seat and an upper outlet valve seat whereby actuation of the valve actuator selectively opens and closes the lower and upper valve seats, an atmospheric vacuum breaker valve mounted for slidable travel on the valve actuator concentric with the diverter collar at the upper end thereof, a closure cap threaded into the upper end of the diverter collar, the closure cap having a valve seat, and a spring for urging the atmospheric vacuum breaker valve upwardly against the closure cap valve seat and for permitting the atmospheric vacuum breaker valve to open upon creation of a negative pressure within the valve to permit ingress of atmospheric air. The closure cap may have an enlarged central opening for air ingress, or a central opening for guiding axial travel of an extension of the valve actuator and a plurality of equispaced openings surrounding the central opening for air ingress.</p> |
