... 2000 4:Produce as customer's requirment Non-pressurized solar water heaterSpecifications1.Solar Keymark,SGS,CE,CCC,ISO9001 2.manufacturer, ... 3.OEMIt is one of the most common used solar water heating system for household, hotel, hospital, project application etc. ... , because the compact system is non-pressurized, water flow depending on gravity water head. This system matched with vacuum tube solar ...