a reservoir connected in common to {HEAD ~ said flow systems} to receive a flow of {TAIL ~ fluid} from each said system 
a reservoir connected in common to { HEAD ~ said flow systems } to receive a flow of { TAIL ~ fluid } from each said system
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH