{TAIL ~ The plug} is forced against {HEAD ~ the axial valve seat} when the valve is closed to deform in both axial and radial directions 
{ TAIL ~ The plug } is forced against { HEAD ~ the axial valve seat } when the valve is closed to deform in both axial and radial directions
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH