An apparatus for sealing a pair of circularly coacting pipe flanges which includes a seal around the outer periphery of both the flanges for sealing the outer periphery and a bolt having a coacting nut extending through the bolt holes of the flange. A first sealing ferrule is positioned between the bolt head and one flange and a second sealing ferrule is positioned between the nut and the other flange. The ferrules include a conical exterior surface tapering inwardly and extending into the bolt holes for preventing the escape of fluid through the bolt holes. Each head and first ferrule and each nut and second ferrule include coacting tapered surfaces for pressing the ferrules into a sealing relationship with the bolt and flanges.