Abstract: A sealing gasket (J) intended to be damped between two pipework connection flanges (5, 9), the said gasket comprising a sealing ring (1) including a rigid metal annular part (11, 13, 18, 16) with which are integral a number of radiating metal lugs (2) capable of being folded along the contour of a support flange. The sealing gasket having to be able to be mounted between flanges of different transverse dimensions, the metal lugs (2) are longer than the corresponding transverse dimension of the largest flanges on which the gasket can be mounted. The lugs can thus be folded to conform with the exact dimension of an assembly flange so that the gasket may be suitably supported centered by the said flange prior to the mutual assembly and tightening of the two flanges.