wherein the tip portion is spaced from the tip wall to provide {HEAD ~ a leakage path} between the annular groove and {TAIL ~ the second check end} 
wherein the tip portion is spaced from the tip wall to provide { HEAD ~ a leakage path } between the annular groove and { TAIL ~ the second check end }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL