solar water heater : 1.certification:ISO9001,ISO14001,CCC,CE,Solar Keymark 2.TU heat pipe vacuum tube 3.high pressure solar water heater:material: ... 1.volume of storage tank:120L,180L,240L,300L2.pressurized water tank: insulating ... stainless stell,1.2mm thickness6.working pressure:normal working pressure:6bar,test pressure:12baradvantages:1.can be operated ...