METHOD OF CONNECTING PIPES WITH HEAT EXCHANGER COLLECTOR Russian patent published in 2019 - IPC B21D39/06 

FIELD: heat exchange.

SUBSTANCE: invention relates to metal forming, particularly, to pipe fastening in tube plates of heat exchangers. Tubes are installed in the collector holes with depth of 0–0.5 mm relative to the inner surface of the collector. Pipe ends mechanical expansion is performed for welding, hydraulic distribution of pipe ends in collector holes is performed in two stages. After each step, mechanical rolling is performed to eliminate the "pocket" in the zone adjoining the inner surface of the collector. At the collector outlet mechanical expansion of the pipes is performed to eliminate the pocket in the zone adjoining the external surface of the collector. After fixation of heat exchange tubes, local low-temperature tempering of the collector is performed in zone of heat exchange tubes fixation and ends of heat exchange tubes for removal of residual stresses in them and maintenance. Then, additional mechanical flaring of the pipe ends at the collector outlet is performed in the zone adjoining the external surface of the collector.

EFFECT: higher reliability of heat exchange tubes attachment assembly in heat exchanger collector.

1 cl, 6 dwg