A filter regulator filters the air entering the signal air path and regulates {HEAD ~ the pressure} in {TAIL ~ the signal air path} to a predetermined pressure 
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A filter regulator filters the air entering the signal air path and regulates { HEAD ~ the pressure } in { TAIL ~ the signal air path } to a predetermined pressure
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH