Tank overfill valve

Abstract From the Canadian patent

An overfill valve having a saddle-shaped flapper, valve element located within an inlet pipe and a mating valve seat disposed about the inner wall of the pipe. A spring couples a weighted float to the valve element and extends generally outward from the pipe. The float moves the valve element from a normally open position to a closed position as the float is raised. A controlled drain aperture through the valve element permits standing fluid within the pipe to drain. The spring allows the float to be moved to permit the pipe to be slid down a storage tank casing. A triggering mechanism is coupled to the float and valve element so that the float shifts a triggering element into the liquid …