Then {HEAD ~ the refrigerant} flows downwardly through header 54 and enters {TAIL ~ the two tubes} forming the second tube circuit 32b arranged in series with the upper tube circuit 32a 
enters
Then { HEAD ~ the refrigerant } flows downwardly through header 54 and enters { TAIL ~ the two tubes } forming the second tube circuit 32b arranged in series with the upper tube circuit 32a
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH