Debris free plug assembly for heat exchange tubes

An explosively activated assembly for repairing a tube, said apparatus comprising a casing assembly disposed within said tube and having an internal bore and an outer diameter slightly less than the inner diameter of said tube, a force transmitting member extending within said bore, explosive means extending within said force transmitting member, booster means extending within said casing assembly for igniting said explosive means, and an energy transfer cord extending from said booster means;

• said casing assembly comprising first and second casing members each having a closed end and an open end, said casing members being connected together at their open ends to define an enclosed chamber, one of said casing members having a bore extending through its closed end for receiving, in a relatively close fit, said energy transfer cord, said energy transfer cord projecting from said closed end of said one casing member and adapted to connect said booster means to externally located detonator means for igniting said booster means and therefore said explosive means, so that said force transmitting member is expanded radially outwardly against said casing to expand said casing radially outwardly against the inner surface of said tube and plug said tube, said chamber containing the debris and gases resulting from detonation of said explosive means and said booster means.