... :ISO9001,CCC,CE,Solar Keymark 2.solar water heater:evacuated tube 3.pressure:non-press Solar new energy: material:1.volume ... tank:120L,150L,180L,240L,300L2.non-pressurized water tank: insulating layer,polyurethane foaming ,thickness:55mm outer shell of tank,titanium ... pressure:0.4bar,3.dust ring gasket :ABS4.evacuated tube:three-target tube,high boron and silicon,content 3.3,structure,gradual ...