This column of the working medium generates pressure, at {HEAD ~ the piston} connected to {TAIL ~ one working medium opening} 
connected to
This column of the working medium generates pressure , at { HEAD ~ the piston } connected to { TAIL ~ one working medium opening }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL