When {TAIL ~ the nut} is rotated in a first direction, the nut shoulder contacts the stem annular flange, urging {HEAD ~ the stem} axially towards the valve body 
When { TAIL ~ the nut } is rotated in a first direction , the nut shoulder contacts the stem annular flange , urging { HEAD ~ the stem } axially towards the valve body
OTH TAIL 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 OTH OTH OTH OTH OTH