Abstract: A compartment of an arc resistant enclosure for an electrical component includes a plurality of wall structures defining an interior space for housing an electrical component. One of the wall structures has aperture structure for permitting pressure and gases to flow there-from and vent from the compartment. A stop structure is associated with the aperture structure. Flap structure is associated with the aperture structure and is movable from a closed position covering the aperture structure to an opened position extending outwardly of the compartment permitting pressure and gas to exit the compartment through the aperture structure. In the closed position, a portion of the flap structure engages the stop structure to prevent the flap structure from collapsing into the interior space of the compartment.