Abstract: A butterfly valve includes an annular, elastic sealing element that encloses an axial opening, a valve disk which is disposed inside the axial opening so as to be rotatable transversal to the axial direction, a device for rotating the valve disk between closed and open positions in order to control a fluid flow through the opening, and at least two valve housing parts that enclose the sealing element in an annular manner and embrace two flanges which are connected to an inlet and an outlet. Conical contact areas of the flanges and/or the valve housing parts cooperate in such a way that the flanges are axially pressed in a sealing fashion against the sealing element by means of the valve housing parts in the operationally mounted state. The flanges are respectively connected in a rigid and positive manner to a couple of clamps.