When the nut is rotated in the direction opposite the first direction, {HEAD ~ the nut shoulder} contacts the nut retaining ring and urges {TAIL ~ the stem} axially away from the valve body 
urges
When the nut is rotated in the direction opposite the first direction , { HEAD ~ the nut shoulder } contacts the nut retaining ring and urges { TAIL ~ the stem } axially away from the valve body
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH