... CCC,CE,ISO9001:2000 4:Produce as customer's requirment Non-pressurized solar water heaterSpecifications1.Solar Keymark,SGS,CE,CCC,ISO9001 ... hotel, hospital, project application etc. It has simple structure and working principle but is the most economical. It is easy to ... get enough water flow pressure, because the compact system is non-pressurized, water flow depending on gravity water head. This ...