TPT November 2009

T ube M ills and R oll F orming L ines

SOME time ago, a brief article entitled “Designing Tube Mill Rolls: Turning Art Into Science” appeared in ITA Member News on the International Tube Association website. The piece, contributed by data M Software GmbH, of Germany, was concerned principally to validate roll tooling for tube welding lines. But the discernment of the two streams in the tube making enterprise was – and is – pertinent to the industry overall. In a contemporary tube mill, roll forming commences when a tailored drafting program

 Attl a spol has installed a new tube mill in Yekaterinburg, Russia

analyses a “flower” custom-crafted on a tube cross-section, then feeds the CAD data to an analytical program that decides the forming stations. Within seconds, this software computes the theoretical (elastic and plastic) strain values on the material to be formed as a function of the influencing variables (ie tube geometry, material gauge, roll configuration, diameter). The entry equipment comes into play; and, not very much later, the exit and collection equipment. Another production run – of simple tubes and uncomplicated shapes; or low thickness-to diameter ratio tubes and complex shapes; or a combination of both – has been completed. That is the applied science of roll forming: and very good science, to judge from the excellence of the product. But it is also the tube maker’s responsibility: • to ensure that every bit of the capability of the roll forming operation is at the service of the application; • to ensure attention to the myriad details of workplace safety and environmental impact, timely delivery, and cost- effectiveness; • to conduct the producer-

client relationship at all times on the principle that an educated consumer makes the best customer. Taken together, all this entails many more imponderables than the scientific component. It is, in fact, an art.

 The T&H Lemont dual capacity tube mill

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N ovember 2009

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