Referring to FIG 1, the outer fins 2 can be rolled by one time forming on outside wall of {HEAD ~ a tube body} 1 with {TAIL ~ inner fins} 17 to manufacture an enhanced heat transfer tube 
with
Referring to FIG 1 , the outer fins 2 can be rolled by one time forming on outside wall of { HEAD ~ a tube body } 1 with { TAIL ~ inner fins } 17 to manufacture an enhanced heat transfer tube
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH