METHOD FOR SECURING TUBES TO TUBE WALLS Russian patent published in 2004 - IPC

FIELD: plastic metal working, possibly securing tubes to tube walls of heat exchange apparatuses using effect of localized directed plastic deforming of tube material. SUBSTANCE: method comprises steps of profiling outer surface of tube ends at forming in each end portion annular protrusion and realizing multiple profiling operations of inner surface of tube end portions by expanding tube and then reducing it along length value less than during tube expanding; determining diameter of annular protrusion in outer surface of tube according to condition providing minimum gap between said annular protrusion and opening of tube wall; after placing tube in tube opening having outer and inner annular grooves, fixing tube against axial motion; then securing tube in opening by applying deforming effort to its inner surface in such a way that to provide cross shifting of web of annular protrusion in outer surface of tube. EFFECT: simplified process of securing tubes to tube walls. 4 dwg