Patent Number: 051942143
Section: abstract

A plugging device, such as a tube plug, and method for plugging a tubular member, such as a nuclear steam generator tube, comprises a locking cup for securing together the plurality of members comprising the tube plug. The plugging device may comprise a first member, such as a shell of a tube plug, a second member, such as bolt means of a tube plug and an annular locking cup disposed in a bore of the first member and having outside diameter threads. The outside diameter threads of the locking cup have a deformed portion with a wave-like pattern for providing resistance during threading and unthreading of the locking cup into and out of the first member. At least one of the second member and the locking cup has at least one recess for receiving a deformable portion of the other of the second member and the locking cup for securing the first member, the second member, and the locking cup together. The metal-to-metal abutment of an outside diameter surface of the locking cup and a plug face of the shell and the metal-to-metal abutment of a taper of the bolt means and a taper of the locking cup may seal a chamber within the shell to prevent fluid flow through the tube plug.