During {TAIL ~ backwash} of {HEAD ~ the 5 micron filter}, normally open valves 72 and 82 are closed, and normally closed valves 130 and 132 are open 
During { TAIL ~ backwash } of { HEAD ~ the 5 micron filter } , normally open valves 72 and 82 are closed , and normally closed valves 130 and 132 are open
OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD 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