Copper-aluminum connecting pipe & air conditioner parts 1)Copper tube:OD:1/4,&3/8,&1/2,& ... ,4,6,7,10, Copper-aluminum connecting pipe & air conditioner parts(1)OD:1/4,&3/8,&1/2,&5/8 ... oxide production, so do not need any treatment can achieve cooling pipe The cleaning requirements.4, good insulation properties: air conditioning ...