The cap is sealingly secured against the body member so as to define a pressurizable cavity in the hollow between the cap and the diaphragm, and the cap having {HEAD ~ a rigid stem} protruding therefrom with a fluid passage extending through the stem and into fluid communication with {TAIL ~ the cavity} 
The cap is sealingly secured against the body member so as to define a pressurizable cavity in the hollow between the cap and the diaphragm , and the cap having { HEAD ~ a rigid stem } protruding therefrom with a fluid passage extending through the stem and into fluid communication with { TAIL ~ the cavity }
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 OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL