METHOD FOR SECURING TUBES TO TUBE PLATES Russian patent published in 2003 - IPC

FIELD: plastic metal working, possibly securing tubes to tube plates of heat exchanging apparatuses with use of effect of localized directed plastic deforming of tube material. SUBSTANCE: method comprises steps of profiling tube ends for forming shaped end portions; placing one end of tube in tube plate opening having outer and inner annular grooves; fixing tube against possible motion in opening of tube plate by applying compression effort to inner surface of tube; making outer annular groove of tube plate opening in the form of end recess; upon securing tube at first fixing it on walls of opening by laterally shifting material of its end portion relative to edge of outer annular groove; then filling volume of inner annular groove due to bending deformation of tube end portion at condition of axial tension of its inner layers for further normalized common radial deformation of joined parts. EFFECT: enlarged manufacturing possibilities of process due to securing tubes with different size of cross section without significantly increased technological effort and cycle duration. 6 dwg