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

FIELD: plastic metal working, namely processes for mounting tubes in openings of tube plates of heat exchangers at using local oriented plastic deforming of tube material. SUBSTANCE: method comprises steps of placing one end of tube in tube plate opening having annular grooves; arranging end surface of tube over front surface of tube plate; fixing tube against its possible motion; welding tube to tube plate by expanding tube; preliminarily sizing tube end according to its outer diameter and shaping sized portion; placing tube in opening of tube plate with minimum gap in such way that its shaped portion is arranged in front of annular grooves of tube plate opening; expanding tube by two stages. First stage is realized before welding tube to tube plate at filling annular grooves of tube plate opening with tube material. It provides high quality filling of volume of annular groove. EFFECT: enhanced operational characteristics of tube-to-tube plates joints. 6 dwg _