The center section includes {TAIL ~ a channel} formed on {HEAD ~ an external surface} thereof, and at least one of the housing members is engaged to the center section to close the channel and form a fluid passage in the center section 
The center section includes { TAIL ~ a channel } formed on { HEAD ~ an external surface } thereof , and at least one of the housing members is engaged to the center section to close the channel and form a fluid passage in the center section
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH