Abstract: The invention relates to a sealing system on a first structural element (1). The inventive system is provided with a first through-opening. A first closing flap (3) that can be rotated around a centric axle and is used for closing the first through-opening is situated in said opening. The sealing system can be coupled to a second structural element (2) in an axial manner in relation to the first through-opening. The first closing flap (3) is provided with a first dynamic seal (9) on the radial outer circumference thereof. An elastic seal (8) is provided on the wall of the first through-opening and in the active area of the first dynamic seal (9). The inner diameter of the elastic seal (8) is smaller in the non-operated state than the outer diameter of the first closing flap (3).