Using the fully automatic medium-frequency welding system specially developed for tubular radiator production it is possible to produce head end tube connections of a high quality, whilst simultaneously achieving exceptionally high productivity. Added to this comes high manufacturing flexibility with partially fully automatic set-up for the welding of various radiator element types (2-3-4-5-6 column elements with variable lengths of between 400mm and 3000mm), as well as high welding process assurance for seal welding through the simultaneous monitoring and synchronous control of up to 12 weld seam joints. The cycle time here lies at approx. 4 seconds per element.