A related object of the invention is to have {HEAD ~ the last step} in {TAIL ~ the series} have a simple recess aft of it to thereby minimize wetted area resistance 
in
A related object of the invention is to have { HEAD ~ the last step } in { TAIL ~ the series } have a simple recess aft of it to thereby minimize wetted area resistance
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH