Pipe union and seal

Abstract

A pipe union and compound seal has a first pipe member with a central passageway, a sealing surface and a flange with a shoulder. The union has a fastening member adapted to slide around the first pipe member. The fastening member has a matching flange to abut the first pipe member's flange and has threads formed along the inner surface of the fastening member. A second pipe member has a matching central passageway and threads formed along its outer surface to receive and engage the fastening member's threads. The second member has a face opposing the first pipe member's sealing surface with a trough in the face for receiving and retaining the compound seal. The compound seal is positioned in the trough and in a first embodiment has a central spring and a U-shaped outer shell surrounding the spring. The open end of the shell is disposed radially inward so that increased pressure within the central passageways increases the sealing engagement between the shell and the pipe union. In a second embodiment, the compound seal is a metallic C-ring made of a relatively hard metal with a coating of softer metal on its outer surface. The second embodiment is suitable for applications involving extremely low or high temperature conditions.

Dependencies are inferred from the claim text.