Abstract: A device for closing and sealing a lead-through (1), comprising means intended to open, clean and again close the lead-through. A cone (2) with a head (21), a rod-shaped part (22) and a sealing surface (23) arranged between said head and said rod-shaped part is arranged with the head inserted into the lead-through. In the end of the cone opposite to the head, the cone is provided with means (24) for connecting the cone to a flush pipe (5) arranged in the form of an extension of the rod-shaped part of the cone. An annular flange (3) is attached to the lead-through and around said rod-shaped cone, inserted into the lead-through, to retain the head of the cone in the lead-through. A sealing surface (31), arranged on the annular flange in the form of a seat, is adapted to correspond to and make contact with the sealing surface of the cone to close and seal the lead-through.