vacuum tube solar water heaters 1.Inner tank: 1).Materials:SUS304/2B,0.5mm(upper deviation),food grade stainless steel; 2).Welding procedure: completely auto argon arc welding; 3)Cover of inner tanks: curved outwards to bear higher pressure 2.Outer tank 1).Materials: a. Galvanized steel with double protection layers,0.41mm thickness; b. Stainless steel SUS304/2B,.041mm,food grade stainless steel 2)Production procedure: a. For galvanized steel outer shell, sheet are jointed-up after crimping; b.for stainless steel : completely auto argon arc welding(same as inner tank welding) 3) Outer cover 3.Insulation layer 1).Materials: CFC-free , environmentally friendly 2).procedure: Using CNC constant temperature, constant pressure quantitative foaming, curing processing, thick insulation layer, ensure the quality more close, well-balanced, insulation more abiding. 4.Brackets Materials: a. galvanized steel with corrosion resistant layer, thickness of 1.5mm b. stainless steel SUS201,thickness of 1.2mm 5.Evacuated tubes 1).Single target All-glass vacuum heat collection tube 2)Three target all glass vacuum heat collection tube 6.Packing:Export standard Cartons 7.Spare parts 1).Electronic heaters as back up inside tanks; 2).1% tubes, tube shoes, silicon rings