EXPANDING U-TUBES INTO STACKED FINS AND TUBE PLATES

摘要

Apparatus for expanding hairpin tubes into a fin pack unit that involves a special clamping fixture for securing the belled ends of the tubes to hold the ends of the tubes immobile as tube expanders are passed through the tubes to expand the tube walls in the fin plates and tube sheets of the unit. The tubes are expanded in tension which permits the bells to be formed against one of the tube sheets thereby eliminating the weakest region in the heat exchanger flow circuit.