{HEAD ~ An annular protrusion} axially extends from {TAIL ~ the valve body} and is symmetrical about the orifice 
axially extends from
{ HEAD ~ An annular protrusion } axially extends from { TAIL ~ the valve body } and is symmetrical about the orifice
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH