The passageway includes a fuel delivery end located in a firebox and {HEAD ~ a fuel infeed end} below {TAIL ~ the plate} 
The passageway includes a fuel delivery end located in a firebox and { HEAD ~ a fuel infeed end } below { TAIL ~ the plate }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL