Abstract: A float valve assembly includes an outlet, a float and a stopper attached to the float. The stopper opens and closes the outlet based on the movement of the float. When the float moves vertically upward, the stopper moves horizontally away from the outlet to open the outlet and allow fluid flow out of the outlet. When the float moves vertically downward, the stopper moves horizontally towards the outlet to close the outlet. Thus, the direction of movement of the stopper is generally perpendicular to the direction of the buoyant and gravitational forces acting on the float. The float valve can be used in an oil separator/filter. The float may be formed of an elastomeric material and the stopper may be a seating needle or other stopper.