... stable quality acquired certification: CE,CCC,ISO9001-2008, SGS, Solar Keymark, SRCC energy saving offer OEM Evacuated tubeDia*Length47*1500 ... , thickness1.0-2.0mm. Water purity for drinking.Outer tank materialColoured plate,galvanized steel, stainless steel(optional).Insulation layerPolyurethane foam ... -1MPaLeak-proof testYesLifespanMore than 15 yearsPackingExport carton, wooden box. Solar Water Tank