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