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