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