An elevated flush valve comprising a vent cover may be used with various assemblies, particularly for high efficiency and high performance toilets, which vent cover has a wall that includes an upper portion, a lower portion configured to define a vent cover inlet opening for receiving air and/or liquid passing upwardly from within a valve body and/or from within a toilet through a toilet inlet when the vent cover is installed on a valve body, an exterior surface, and an interior surface defining a vent cover passage for air passing upwardly from the vent cover inlet opening. At least the upper portion of the vent cover wall is configured for contacting an interior surface of a valve body at a location above an inlet of an overflow or venting tube on a valve body when the vent cover is installed on a valve body and wherein the valve cover wall is configured to at least partially divert flow of fluid from entering an inlet of an overflow tube or a venting tube on a valve body when the vent cover is installed on a valve body.