Abstract: A method and apparatus for removing burrs from inside slotted metal liners exposes the burrs to a high-intensity gas flame that effectively oxidizes or incinerates the burrs, without inducing undesirable temperature levels in the parent metal of the slotted liner. This is accomplished using a torch head assembly having multiple gas torch nozzles disposed radially around the circumferential perimeter of the torch head, such that when the torch head is passed through the interior of a slotted liner, the flames are directed toward the interior surface of the liner. Auxiliary oxygen is introduced at the nozzle outlets, resulting in a large increase in flame velocity and intensity and, in turn, an increase in the flame temperature. The auxiliary oxygen may be introduced through annular passages surrounding the nozzles, such that the auxiliary oxygen effectively forms a cylindrical curtain surrounding the flame at each nozzle.

Abstract: A method of reducing slot width in slotted tubular liners. A slotted tubular liner (1) is provided having an interior surface (3), an exterior surface (2) and a plurality of slots (4) extending between the interior surface and the exterior surface. One or more contoured rigid forming tools (7) are provided. Pressure is applied to either the interior surface (3) or the exterior surface (2) of the slotted tubular liner (1) with the contoured rigid forming tools (7). The contoured rigid forming tools are then moved in a sweep pattern traversing either the interior surface or the exterior surface of the slotted tubular liner, until plastic deformation narrows the width of the plurality of slots (4) to within desired tolerances. The method does not require the same precise positioning of previously known methods and, as such, provides a combination of increased output and lower cost.