A series of packing nuts 18 are threadably mounted on respective packing studs 20 so as to adjust the loading on {HEAD ~ the packing} within {TAIL ~ the bonnet} and around the valve stem 
within
A series of packing nuts 18 are threadably mounted on respective packing studs 20 so as to adjust the loading on { HEAD ~ the packing } within { TAIL ~ the bonnet } and around the valve stem
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH