... :evacuated tube pressure:non-pressuried Solar new energy:material:1.volume of storage tank:120L,150L,180L,240L,300L2. ... 0.4mm inner tank,stainless steel SUS304-2B,thickness:1.2-1.5mm,normal working pressure:0.4bar,3.dust ring ... coating5.frame:,aluminium alloy,1.2mm thickness6.controller:SR500advantages:1.can be operated completely automatic if connect with intelligent controller.2.Simple structure,easy ...