The diaphragm floats freely above {TAIL ~ the generally flat top} of {HEAD ~ the dome}, not in any significant way clamped, pinched or held against the truncated dome shaped valve seat 
The diaphragm floats freely above { TAIL ~ the generally flat top } of { HEAD ~ the dome } , not in any significant way clamped , pinched or held against the truncated dome shaped valve seat
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH