When the poppet valve is opened, {HEAD ~ fluid} flows through a flow channel in {TAIL ~ the valve assembly} 
flows in
When the poppet valve is opened , { HEAD ~ fluid } flows through a flow channel in { TAIL ~ the valve assembly }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL