METHOD OF TUBE ATTACHMENT IN TUBE PLATES Russian patent published in 2001 - IPC

FIELD: treatment of metals by pressure. SUBSTANCE: method may be used for attachment of tubes in tube plates of heat-exchange apparatus with use of effect of localized directed plastic deformation of tube material. Internal circular swelling is formed on internal surface of tube adjacent to its end. Tube is inserted in tube plate hole provided with circular grooves on its surface and fixed to prevent its displacement. Then compressing force is applied to internal surface of tube by means of rollers of mechanical rolling, thus ensuring tube attachment. Length of rollers exceeds width of internal circular swelling. As a result, sufficient filling of circular groove spaces of tube plate is provided without cutting of tube walls in presence of conicity of rollers of mechanical rolling. EFFECT: enhanced efficiency. 6 dwg