MISOL 3/4" Air Vent valve for Solar Water Heater, Pressure Relief valve air vent valve, 3/4" Technical Specifications: 1, Nominal pressure: 1.6MPa 2, Working Medium: Water 3. Temperature 0 to 110 Celsium Degree. 1. Brass vertical automatic vent valve is for hot and cold water pipeline system and low pressure vessel to exclude air; 2. valve should be installed vertically at highest point in the piping system. hot water heating system installed in the piping system should be at the end of top; 3. Pressure should be adjusted before use, it's forbidden to open the valve during installation and use