A piston is disposed in {HEAD ~ each cylinder} for reciprocal movement therein in order to pump the fluuid from {TAIL ~ the inlet} to the outlet 
A piston is disposed in { HEAD ~ each cylinder } for reciprocal movement therein in order to pump the fluuid from { TAIL ~ the inlet } to the outlet
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH