{TAIL ~ Cylindrical valve member 24b} is preferably made from {HEAD ~ a resilient, self sealing material}, such as, for example, polytetrafluorethylene, commonly available, for example under the trade name TEFLON 
{ TAIL ~ Cylindrical valve member 24b } is preferably made from { HEAD ~ a resilient , self sealing material } , such as , for example , polytetrafluorethylene , commonly available , for example under the trade name TEFLON
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH