A main valve has a first chamber on one side downstream from the metering valve, and {TAIL ~ the valves outlet} is connected to {HEAD ~ this first chamber} 
A main valve has a first chamber on one side downstream from the metering valve , and { TAIL ~ the valves outlet } is connected to { HEAD ~ this first chamber }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD