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