METHOD FOR FASTENING TUBES IN TUBE PLATES Russian patent published in 1999 - IPC

FIELD: plastic metal working, namely processes for fastening tubes in tube plates by localized directed plastic deforming of tube material. SUBSTANCE: method comprises steps of forming annular protrusions on outer surface of end portions of tube, placing tube in plate having openings with rectangular cross section annular grooves, matching protrusions and grooves, fixing tube against its possible axial motion and fastening tube in tube plate at applying compression effort at side of tube plate inner surface; forming packings along edges of annular grooves of tube plate between tube and tube plate by cold plastic deformation due to forming annular trapezoidal cross section protrusions on outer surface of tube end portion and forming annular triangle cross section recesses with acute angles turned towards groove at both sides of annular grooves of tube plate along distance equal to length of large base of trapezoidal cross section of protrusion. EFFECT: possibility of normalize and create tube effort acting upon wall of opening in tube plate, enhanced stable strength and fluid-tightness of assembled unit, simplified guaranteed matching of annular protrusions of tube with annular grooves of tube plate at placing tube in plate. 4 dwg