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 exchanging apparatuses due to use of localized directed plastic deformation of tube material. SUBSTANCE: method for securing tubes comprises steps of making annular trapezoidal cross section protrusions on outer end portions of tube; placing tube to tube opening; matching annular protrusions of tubes with annular grooves of tube opening; fixing tube against possible motion for it subsequent fastening in tube plate opening due to applying compression effort to inner surface of tube. Trapezoidal cross section protrusions have large base equal to width of annular groove of tube opening. At process of securing tube lateral surface of protrusion is embedded into surface of annular groove. It causes pressing out of tube material in direction of applied effort. EFFECT: enhanced strength parameters of rolled joint. 5 cl, 13 dwg