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