Molded plastic gasket having an improved sealing bead

A gasket comprising a thin main gasket body of a synthetic plastic material having a pair of expansive main surfaces and defining a plurality of openings including at least one service opening and a plurality of bolt holes, said gasket body defining a sealing bead which is integral with said body, which is vertically moveable relative to said body, and which surrounds said service opening, each sealing bead comprising a first bead segment projecting outwardly beyond one of said main surfaces and a second bead segment integrally formed with said first bead segment in line with said first bead segment and extending oppositely to said first bead segment, each said sealing bead being formed integrally with said main body via a cantilever section at each side of said sealing bead, each said cantilever section having a thickness no more than about 40 percent of the thickness of said main body and a width which is no less than about 75 percent of the thickness of the cantilever section, whereby when said gasket is clamped and loaded between a pair of flanges, said sealing bead segments cooperate to effect seals with said flanges thereat and said cantilever sections cooperate to provide restorative energy under loading.