초록 ▼

A process for brazing a sleeve within a tube which is resistant to longitudinal expansion is disclosed herein. In the first step of the process, a thermally induced radial expansion is induced in the tube in a first longitudinal section of the tube which does not include the ring of brazing alloy wh

A process for brazing a sleeve within a tube which is resistant to longitudinal expansion is disclosed herein. In the first step of the process, a thermally induced radial expansion is induced in the tube in a first longitudinal section of the tube which does not include the ring of brazing alloy which circumscribes the sleeve. In the second step of the process, a brazing heat is applied across the longitudinal section of the tube which does include this ring of brazing material. The residual tensile stress created by the thermally induced radial expansion in the tube avoids the creation of gaps in the braze joint between the sleeve and the inner walls of the tube. This process is particularly useful in creating high-quality braze joints in sleeving operations in nuclear steam generators, where the heat exchange tubes which need to be sleeved may be partially or completely prevented from expanding in the longitudinal direction due to sludge deposits in the generator.

대표청구항 ▼

A process for brazing a metallic sleeve concentrically disposed within a metallic tube, wherein said sleeve includes a brazing reservoir which includes a brazing alloy, comprising the sequential steps of: (a) applying radiant heat from a heat source which is movable within said sleeve and tube aroun

A process for brazing a metallic sleeve concentrically disposed within a metallic tube, wherein said sleeve includes a brazing reservoir which includes a brazing alloy, comprising the sequential steps of: (a) applying radiant heat from a heat source which is movable within said sleeve and tube around a first longitudinal section of the tube which does not surround any portion of the brazing reservoir of said sleeve until said first longitudinal section is radially expanded by the radiant heat; (b) moving said heat source to a position adjacent to said brazing reservoir of said sleeve, and (c) applying radiant heat from said heat source to said brazing reservoir of said sleeve until said brazing alloy melts and brazes said sleeve to said tube.