METHOD FOR SECURING TUBES TO TUBE PLATES Russian patent published in 2001 - IPC

FIELD: plastic metal working, namely processes for securing tubes to tube plates of heat exchangers with use of effect of localized oriented plastic deformation of tube material. SUBSTANCE: method comprises steps of placing tube after preliminary operations in tube plate opening having two annular grooves; fixing tube against possible motion and fastening it due to applying compression effort to its inner surface by expansion; preliminarily profiling outer surface of tube by forming on it cone portion whose apex is arranged behind end of tube and portion having curvilinear generatrix turned to tube axis and joined with cone portion; placing tube in opening of tube plate without gap and arranging portion with curvilinear generatrix in front of annular grooves of tube plate opening. EFFECT: possibility for providing necessary characteristics of "tube-to-tube plate" joints without applying increased pressure to inner surface of tube. 5 dwg