Abstract: There is disclosed a vent for venting air from a system of the type which conducts fluid under pressure. The vent includes a chamber, a ball valve within a top wall of the chamber, and a float within the chamber which is arranged for vertical movement therein. A lever which carries a valve ball element is arranged for pivotal movement against the inner surface of the chamber top wall for disengaging the ball element from the valve when the valve is opened. When the valve is opened, the lever and ball element fall away from the valve. When the vent closes, the float acts upon the lever for guiding the ball element into seating relation with the vent valve.