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