The direction of flow of {TAIL ~ liquid} through the shell 12, however, has no effect on {HEAD ~ efficiency} and so does not matter 
The direction of flow of { TAIL ~ liquid } through the shell 12 , however , has no effect on { HEAD ~ efficiency } and so does not matter
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH