a valve seat between said inlet and outlet ports, wherein said valve seal seals against said seat when said {TAIL ~ plunger} is in said valve closed position and is spaced from said seat when said plunger is in {HEAD ~ said valve open position} 
a valve seat between said inlet and outlet ports , wherein said valve seal seals against said seat when said { TAIL ~ plunger } is in said valve closed position and is spaced from said seat when said plunger is in { HEAD ~ said valve open position }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD