METHOD FOR REPAIR OF TUBE BUNDLES IN HEAT-EXCHANGE DEVICES Russian patent published in 2010 - IPC B23P6/00 B21D53/08 B21D41/00 

FIELD: technological processes.

SUBSTANCE: invention relates to repair of heat-exchange devices. After preparation of tubes by straightening, cutting to measure and scraping of inner surface of ends, annular ledges are formed on them with outer and inner side conical surfaces. Length of generatrix of outer side surface exceeds length of generatrix of inner side surface. Inner surface is shaped by means of expanding-calibration of tube end with a rigid puncheon, which is carried out after preparation of tube. Outer surface is shaped by a cascade radial squeezing of calibrated section of tube with segments of split die. Die comprises finishing and preliminary gravures and working belt between them. In process of squeezing they carry out reprofiling of calibrated section of tube into maximum and minimum squeezed sections and conical section between them. Then tube is burnished at its maximum squeezed section. Working diametre of burnisher tooth is equal to initial inner diametre of tube. At the same time cavity of tube end is produced with inner diametre that equals to inner diametre of tube. Produced tips are installed in holes of tube plates and fixed.

EFFECT: invention provides for achievement of high service characteristics of split joints of heat exchange tubes with tube plates.

8 dwg