There can be several introduction gaps or {HEAD ~ orifices} operating at {TAIL ~ one time} to increase the total production throughput 
operating at
There can be several introduction gaps or { HEAD ~ orifices } operating at { TAIL ~ one time } to increase the total production throughput
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH