... 4, (2) Length:3,4,6,7,1 Air Conditioner tube(1)Copper tube:OD:1/4,&3/8,& ... , so also there is no other way of heat or other solution exists to complete the connection prone ... needed to connect pipe insulation, and to improve the air conditioner's energy efficiency, should further improve the connection ... 3 times the maximum working pressure, so the use of copper and aluminum connecting pipe will not be ...