METHOD FOR SECURING TUBES TO TUBE PLATES Russian patent published in 2002 - IPC

FIELD: plastic metal working, possibly fastening tubes in tube openings of heat exchange apparatuses at using effect of localized directed deformation of tube material. SUBSTANCE: method comprises steps of preliminarily calibrating tube end according to its outer diameter and forming inner bulge along part of calibrated portion; then profiling said part for forming curvilinear portion with generatrix turned towards tube axis and joined with part of calibrated portion having no bulge; placing tube in tube plate opening with annular grooves at arranging said grooves symmetrically relative to curvilinear portion of tube in order to form in curvilinear portion (by means of tube walls) different-rigidity supporting brackets; then fixing tube against its possible motion and fastening it at applying radial pressure to its inner surface. EFFECT: enhanced operational characteristics of joints. 10 dwg