Preferably, {HEAD ~ the annual chamber} extends from the inlet port to an axially opposite end of {TAIL ~ the first hub collar} 
Preferably , { HEAD ~ the annual chamber } extends from the inlet port to an axially opposite end of { TAIL ~ the first hub collar }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL