... :CCC,CE,ISO9001:2000 4:Produce as customer's requirment Non-pressurized solar water heaterSpecifications1.Solar Keymark,SGS,CE,CCC,ISO9001 ... get enough water flow pressure, because the compact system is non-pressurized, water flow depending on gravity water head. This system ... : 46eter: 460mm9) Pressure: 0Pa10) Heat preservation: 72hrs11) Hail resistance: 25mm Non-pressure Compact solar water heater