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