{TAIL ~ An internal valve} 7, further comprising a biasing element to cause the equalization member to move to the at least third operating position when the piston is at {HEAD ~ the second piston position} 
{ TAIL ~ An internal valve } 7 , further comprising a biasing element to cause the equalization member to move to the at least third operating position when the piston is at { HEAD ~ the second piston position }
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 OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD