| 摘要 |
<p>A pilot valve for controlling main valve operation to relieve overpressure from a fluid system to which the main valve is connected. Opening and closing of the pilot valve is effected by a movable disc which carries with it an annular resilient gasket. A seating surface, defined on the end face of the inlet nozzle, cooperates with the gasket when the disc is in closed position for effecting a pressure tight seal against fluid flow to the discharge side of the valve. A perforated gasket retainer communicates exposure of upstream pressure to diirectly against the formed seal whereby at incipient lift of the disc initial flow discharge incurs minimum pressure drop therepast. A two-stage huddle chamber surrounding the seal area is capable of responding to the fluid pressure of even initial discharge to accelerate full lift opening of the disc.</p> |
