US Patent 10151212 Clapper arm retention device

A retention device for restraining movement of a clapper arm used in a clapper valve during removal of a clapper valve shaft that extends through the clapper arm. The device includes an adapter plate mounted to a wall of a clapper valve casing wherein the adapter plate includes a hole having an internal thread. The device also includes a retaining element having an outer thread that threadably engages the internal thread. Further, the device includes a retaining end that is formed on an end of the retaining element, wherein the retaining end includes a circumferential contact surface that abuts against the clapper arm to restrain movement of the clapper arm during removal of the clapper valve shaft.