The hot water in the tank is maintained at a constant level so that the quantity of {HEAD ~ water} discharged by {TAIL ~ the dipper} is fixed 
The hot water in the tank is maintained at a constant level so that the quantity of { HEAD ~ water } discharged by { TAIL ~ the dipper } is fixed
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH