An improved tapping sleeve assembly (114) comprising a sleeve (115) configured to clamp a main fluid conduit (116) oriented about a longitudinal axis (x-x), the sleeve having a first member (134), a second member (140) separate from the first member, and a connection assembly (121) between the first member and the second member, the first member having a branch aperture (123) configured to communicate with a branch fluid conduit (129), the connection assembly configured and arranged to tighten the first and the second members to the main fluid conduit, a gasket (132) disposed between the first member and the main fluid conduit, the gasket comprising a flexible sheet (133) and a thickened aperture seal (122) configured to extend around the branch aperture between the sleeve and the main fluid conduit, the gasket comprising an inwardly protruding circumferential seal bead (137a) extending substantially transverse to the longitudinal axis and intersecting an inwardly protruding portion of the aperture seal, the circumferential seal bead having a main length portion (139), the inwardly protruding portion of the aperture seal having a radial thickness (152) and the main length portion (139) of the circumferential seal bead having a radial thickness (141) less than the radial thickness of the inwardly protruding portion of the aperture seal, the circumferential seal bead having a junction end portion (153) between the main length portion of the circumferential seal bead and the inwardly protruding portion of the aperture seal, and the junction end portion of the circumferential seal bead having a non-uniform radial thickness (163).