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 at using effect of localized directed plastic deforming of tube material. SUBSTANCE: method comprises steps of profiling tube ends for forming end portions having loaded and supporting zones and transition zone between them; placing one end portion into tube plate opening having combined annular groove provided with rectangular and triangular cross section grooves; placing small base of annular transition zone of end portion in front of edge of annular groove with rectangular cross section; then fixing tube against its possible motion and securing it to tube opening by applying compression effort to inner surface of loaded zone. EFFECT: non-detachable joint with improved operational characteristics. 5 dwg