Patent attributes
A closure arrangement for a tank includes a tank lid and an opening flange. The opening flange has first and second tank flange lips spaced by an offset distance. The tank flange lips extend toward one side of the tank. The tank has a lid flange with first and second lid lips spaced by an offset distance corresponding to the offset distance. The lid lips extend, at least in part, toward a second side of the tank. The lid lips include first and second walls arranged at a tank interior side of the respective first and second tank flange lips in an offset direction. When the tank lid is closed over the tank opening, one or more seals engage the tank flange lips from the tank interior side and engage the lid lip walls of the lid flange from an exterior side of the tank in the offset direction.