A controller is preferably in communication with each of the valves for selectively moving {TAIL ~ each} of the valves between an open position and {HEAD ~ a closed position} 
A controller is preferably in communication with each of the valves for selectively moving { TAIL ~ each } of the valves between an open position and { HEAD ~ a closed position }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD