Desirably said second valve includes a bleed path which opens prior to full opening of the second valve so as to effect {HEAD ~ a controlled release} of {TAIL ~ pressure} through said gas outlet 
of
Desirably said second valve includes a bleed path which opens prior to full opening of the second valve so as to effect { HEAD ~ a controlled release } of { TAIL ~ pressure } through said gas outlet
OTH OTH OTH OTH OTH OTH 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 OTH OTH OTH OTH