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