Abstract: A self-locking seal ring is disclosed. The self-locking seal ring includes a ring body having a tab end segment on one end and a channel end segment on the opposite end. A lock tab is provided on the tab end segment, and a lock channel is provided on the channel end segment for receiving the lock tab. The self-locking seal ring is easy to install in a ring groove in a main butterfly plate of a butterfly valve, for example, and facilitates optimum sealing of the main butterfly plate with respect to the butterfly valve housing.

Abstract: A flexible coupling for transferring a fluid between two fluid conduits and for providing an effective fluid seal is disclosed. The device includes a body portion containing a hollow interior open on opposite ends thereof and having a raised cylindrically shaped end collar formed around at least one of the open ends. The end collar defines an outwardly opening, endlessly extending groove in which a seal ring assembly is removably disposed and which projects out of the groove to provide an effective fluid seal against a cylindrically shaped bearing surface of a hollow conduit collar, the latter being attachable to one of the fluid conduits. A pair of stop members disposed in the conduit collar confines the end collar for both rotatable and translatable sliding movement therebetween. The body portion is also angularly adjustable relative to a centerline of the hollow interior of the conduit collar. Various removable seal ring and biasing spring configurations for use in the end collars are also disclosed.