wherein the diaphragm is generally circular, and the truncated surface being the surface that inter engages the diaphragm, the valve seat further comprising a surface of {HEAD ~ the dome} that slopes away from {TAIL ~ the truncated surface} and is adapted to remain disengaged from any portion of the diaphragm 
slopes away from
wherein the diaphragm is generally circular , and the truncated surface being the surface that inter engages the diaphragm , the valve seat further comprising a surface of { HEAD ~ the dome } that slopes away from { TAIL ~ the truncated surface } and is adapted to remain disengaged from any portion of the diaphragm
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH