Vertical expanders are more suitable for repetitive production and high-volume manufacturing with heat exchanger lengths of up to 2.7 meters and a maximum number of simultaneously expandable tubes reaching 420. The expansion occurs through the introduction of shaped bullets inside the tubes along their entire length, with the final forming of the bells or flares for the insertion of the return bends. Always focused on improving productivity, for our vertical expanders we have adopted a system for the automatic replacement of the rods that can reduce the machine set-up time dramatically, when the thickness of the tube changes; a patented system, changes the complete rod configuration.