{HEAD ~ An annular recess} is formed in {TAIL ~ an outer surface} of the orifice ring and has first and second axially spaced walls 
is formed in
{ HEAD ~ An annular recess } is formed in { TAIL ~ an outer surface } of the orifice ring and has first and second axially spaced walls
HEAD 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