In this embodiment, {HEAD ~ the generally flat truncated surface} of {TAIL ~ the dome} shaped valve seat is the diaphragm engaging surface 
of
In this embodiment , { HEAD ~ the generally flat truncated surface } of { TAIL ~ the dome } shaped valve seat is the diaphragm engaging surface
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH