{HEAD ~ The top portion} 21 of the T shaped valve member 20 forms {TAIL ~ a sealing surface} 30 for selectively substantially preventing fluid flow through the opening 26 
forms
{ HEAD ~ The top portion } 21 of the T shaped valve member 20 forms { TAIL ~ a sealing surface } 30 for selectively substantially preventing fluid flow through the opening 26
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH