In addition, the bias means control {HEAD ~ deformation} of the valve member so as to prevent {TAIL ~ undesirable, excessive opening} of the valve 
to prevent
In addition , the bias means control { HEAD ~ deformation } of the valve member so as to prevent { TAIL ~ undesirable , excessive opening } of the valve
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH