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

FIELD: plastic metal working. SUBSTANCE: method comprises steps of preliminarily calibrating tube end portions by outer diameter at flaring them; then forming shaped zone with curvilinear generatrix by reducing each end of tube in range of length of calibrated portion; separating (by means of shaped portion) calibrated portion by inner and outer parts; placing tube in tube plate opening having outer and inner annular grooves; arranging inner part of calibrated portion of tube in front of inner annular groove of tube plate in order to provide tube resting upon surface of opening wall at one side relative to outer annular groove; fixing tube against possible motion due to applying radial pressure to inner surface of tube; initially filling volume of inner annular groove of tube plate opening with material of inner part of calibrated portion of tube due to deforming shaped zone with curvilinear generatrix. EFFECT: enhanced operational characteristics of tube-to-tube plate joints. 8 dwg