... tube:inner screw thread/inner grooved pipe or bare/smooth pipe. Heat Exchanger:1.Finned Tube Heat Exchanger 2.Follow custom's design ... 3.Tube diameter ... :7MM,7.94MM,9.52MM,15.88MM 4.condenser ,evaporator coilSpecifications:O.D.Copper Tube ... processTube bending, Punching the fins, Tube expanding, Degreasing, Welding and assembling, ...