As soon as the valve element reaches the desired extreme position in contact with a stopper, {HEAD ~ the motor} is rotated to deform the elastic coupling member and to improve {TAIL ~ the contact} between the valve element and the stopper 
As soon as the valve element reaches the desired extreme position in contact with a stopper , { HEAD ~ the motor } is rotated to deform the elastic coupling member and to improve { TAIL ~ the contact } between the valve element and the stopper
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH