The number of vanes 56 may vary but they are preferably spaced between 20 degrees and 30 degrees apart around {HEAD ~ the circumference} of {TAIL ~ the cylindrical wall member} 32 
of
The number of vanes 56 may vary but they are preferably spaced between 20 degrees and 30 degrees apart around { HEAD ~ the circumference } of { TAIL ~ the cylindrical wall member } 32
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH