... cheap and reabile solution,simple structure,easy installation. 3.Outsta non-pressure solar water heater:1.Vacuum Tube Specifications:Dia 47x1.6,Dia58x1.8 ... stainless3.System pressure:The factory test pressure 0.2MPa pressure run4.Tank shell:Brushed silver porcelain plate5.Tube Number Range:16,18,20, ... .30m29.Cheap and reliable solution, simple structure,easy installation non-pressure solar water heater