bias means comprising {HEAD ~ at least one flexible strand} maintained under {TAIL ~ tension} connected between said valve member and said valve seating portion on the other side of said opening for maintaining a substantial seating force on said valve member when said valve opening has closed, and 
maintained under
bias means comprising { HEAD ~ at least one flexible strand } maintained under { TAIL ~ tension } connected between said valve member and said valve seating portion on the other side of said opening for maintaining a substantial seating force on said valve member when said valve opening has closed , and
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH