... /4, (2) Length:3,4,6,7,1 Air Conditioner tube(1)Copper tube:OD:1/4,&3/8,&1 ... needed to connect pipe insulation, and to improve the air conditioner's energy efficiency, should further improve the connection pipe ... pipe copper tube design is 1.5 times the wall thickness, not only to ensure strength and relative connecting ... to install and transfer machines. copper-aluminum tube & Air Conditioner tube