VENT VALVE FOR LIQUID TANK INCORPORATING ANTI-OVERPRESSURE SAFETY FEATURE

摘要

The invention relates to a vent valve (1) for a liquid tank comprising a chamber (10) incorporating: - means (22, 24, 26) for providing function of automatically closing the valve if the tank turns over, or "ROV" function; - means (44, 46) for providing an overfill prevention function preventing the tank from being filled beyond a predetermined level, or "ISR" function; - means (28, 30, 32) for allowing gases to escape to the external atmosphere in the event of an overpressure exceeding a predetermined threshold, or "OPR" function; - means (36, 38, 40, 42) to allow air to enter the tank when the pressure obtaining within the tank is below atmospheric pressure, or "bypass" function.