Air Conditioner tube 1)Copper tube:OD:1/4,&3 ... 4, (2) Length:3,4,6,7,1 Air Conditioner tube(1)Copper tube:OD:1/4,&3/8,&1 ... to connect pipe insulation, and to improve the air conditioner's energy efficiency, should further improve the connection pipe insulation ... connect pipe insulation, reducing the cold waste, improve the energy efficiency level.5, safety performance: copper-aluminum connecting pipe ...