Re opening of the main valve is accomplished with the aid of a bypass system connecting {HEAD ~ the upstream side} of {TAIL ~ the metering valve} to the main valves first chamber 
of
Re opening of the main valve is accomplished with the aid of a bypass system connecting { HEAD ~ the upstream side } of { TAIL ~ the metering valve } to the main valves first chamber
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH