Preferably, {HEAD ~ the valve member} is compressed within {TAIL ~ the chamber} to provide the resilient bias required to move the valve member into sealing engagement with the valve seat 
is compressed within
Preferably , { HEAD ~ the valve member } is compressed within { TAIL ~ the chamber } to provide the resilient bias required to move the valve member into sealing engagement with the valve seat
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH