METHOD FOR SECURING TUBES IN TUBE PLATES Russian patent published in 2000 - IPC

FIELD: plastic metal working, namely processes for securing tubes to tube plates of heat exchanging apparatuses with use of localized directed plastic deformation of tube material. SUBSTANCE: method comprises steps of forming annular protrusions with trapezoidal cross section on outer surfaces of tube ends; placing tube into opening of tube plate having annular grooves with rectangular cross section; matching annular protrusions of tubes with annular grooves of said openings; fixing tube against motion for subsequent securing it to tube plate by applying compression effort to inner surface of tube; making on inner surface of tube annular thickened portions symmetrical relative to annular protrusions. In order to realize it, diameter of annular protrusions of tube is more than that of opening for tubes. Before placing tube into opening, its end portions with profiled outer surfaces are reduced. EFFECT: enlarged manufacturing possibilities of method. 2 cl, 9 dwg