Suction valve with release timing chamber

摘要

In addition to seating on its valve seat during the combined compression and discharge stroke, the suction valve (20) seats on the structure associated with the valve seat (20) which has at least one shallow recessed area (30-5). In seating on its valve seat, the suction valve (20) seats on the structure defining the shallow recess (30-5) to trap fluid therein. The recess (30-5) serve to reduce the area available for adhesion and the trapped fluid pressure provides an opening bias to the suction valve (20). If necessary, or desired, restricted communication between the compression chamber and the shallow recess (30-5) can take place to provide a higher pressure in the recess at the time of transition from discharge to suction.