{HEAD ~ The fine threading} of {TAIL ~ the valve stem} and the larger seat area allow for precise resistance to flow 
of
{ HEAD ~ The fine threading } of { TAIL ~ the valve stem } and the larger seat area allow for precise resistance to flow
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH