In addition, the present apparatus comprises surface interfaces between a slidable sleeve and a mandrel to minimize a probability of {TAIL ~ mandrel and sleeve separation} during the plungers ascent phase and {HEAD ~ a risk} of plunger stall 
In addition , the present apparatus comprises surface interfaces between a slidable sleeve and a mandrel to minimize a probability of { TAIL ~ mandrel and sleeve separation } during the plungers ascent phase and { HEAD ~ a risk } of plunger stall
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH