Solar water heater 1.certification:ISO9001,ISO14001,CCC,CE,Solar Keymark 2.solar water heater:heat pipe tube 3.pressure:press Solar water heater: material:1.volume of storage tank:120L,180L ... -1.5mm,normal working pressure:6bar,test pressure:12bar3.dust ring gasket :EPDM4.evacuated tube:three-target tube,high boron and silicon,content ...