{HEAD ~ a sealing portion} disposed between {TAIL ~ the guide portion} and the tip portion and disposed adjacent the valve seat and 
{ HEAD ~ a sealing portion } disposed between { TAIL ~ the guide portion } and the tip portion and disposed adjacent the valve seat and
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH