non-pressure solar water heater: 1.High efficiency. 2.cheap and reabile solution,simple structure,easy installation. 3.Outsta non-pressure solar water heater:1.Vacuum Tube Specifications:Dia 47x1.6,Dia58x1.8,Dia58x2.12.Water Tank Liner: Imported SUS304-2B food grade stainless3.System pressure:The factory test pressure 0.2MPa pressure run4.Tank shell:Brushed silver porcelain plate5.Tube Number ...