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

FIELD: plastic metal working, namely processes for mounting tubes in tube plates of heat exchangers at using effect of local oriented plastic deforming of tube material. SUBSTANCE: method comprises steps of placing one end of preliminarily prepared tube in tube plate opening having inner and outer annular grooves; fixing tube against its possible motion and mounting it in opening of tube plate by expanding at applying compression effort to inner surface of tube; realizing expanding by two stages: at first stage forming annular supporting protrusion on tube at filling volume of inner annular groove of tube plate opening with tube material; at second stage pressing out tube material from its free end to supporting annular protrusion. EFFECT: possibility for achieving desired operational characteristics of expanded joint without increasing compression efforts acting upon inner surface of tube. 7 dwg