... the vacuum tubes to use long time. Non-pressurized Solar Water Heater TECHNICAL DATAWATER STORAGE TANKSMaterial of out ... and outlet holeMale G 1/2Tank size420,460,470,475,480,500mm or Customer demandWelding:Argon ... borosilicate 3.3 glassOuter tube dia. & thicknessØ58±0.7mm; Glass thickness 1.6±0.15mmInner ... steel / Stainless steel/aluminium alloyBracket angle:0,18,22,38,45 optional, pitched roof, flat ...