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

FIELD: plastic metal working, namely fastening tubes in tube plates of heat exchange apparatuses. SUBSTANCE: method comprises steps of forming annular protrusions with trapezoidal and triangular cross sections on outer surface of end portions of tube; placing tube in tube plate opening having annular rectangular cross section grooves for matching trapezoidal protrusions of tube with said annular grooves; fixing tube against its possible motion and fastening it in tube plate at applying compression effort upon inner surface of tube; at process of fastening forming additional annular packings on contact surfaces of joined members in zone of triangular cross section protrusions of tube. Additional annular packings are formed at simultaneous engagement of all protrusions of tube with surface of opening in tube plate at condition of initial contact of triangular cross section protrusions or trapezoidal cross section protrusions. EFFECT: enhanced fluid tightness of joint without seaming tube ends. 4 cl, 6 dwg, 1 ex