TPT November 2008

T echnology U pdate

Inductive heating plant for 56" Ø pipe bends

SMS Elotherm, Germany, has received an order from Tectubi Raccordi SpA (Allied Group), an Italian producer of pipe bends, for a ‘Hamburg method’ inductive heating plant for the production of pipe bends. With inductor power inputs of 2,400kW and 1,600kW, the plant is claimed to be the world’s most powerful of its type. Commissioning is scheduled to start at the start of 2009. The scope of the order includes the equipment for preheating the still straight pipe section, plus two medium-frequency infeed units for heating the bent pipe section. In addition, the order covers three sets of inductors for the production of pipe bends with diameters from 36" to 56". The heating plant will be designed for bends of standard steel and austenitic grades, and will be able to process pipes with wall thicknesses of up to 60mm. The power input of the first inductor amounts to 2,400kW, while the bent inductor will be rated for a maximum power input of 1,600kW. The transistorised converters will be equipped with SMS Elotherm digital control,

and be connected to the PLC via Profibus facilities. Two temperature cameras installed at the inductor outlets provide the data for power setting as a function of the pipe feed motion. The Hamburg method for the production of pipe bends involves pushing pipe sections over a mandrel which has the curvature required for the finished

 Fabrication of a 24" pipe bend with inductive heating

undertaken by means of the bent inductor and the associated medium-frequency infeed unit. This method is suitable for an array of materials. After forming, the wall thicknesses are nearly identical over the complete pipe. In addition, the cross-section of the pipe bend maintains the circular contour of the starting pipe. SMS Elotherm GmbH – Germany Fax : +49 2191 891 726 Email : m.oelmann@sms-elotherm.de Website : www.sms-elotherm.com

pipe bend. The feed-forward movement is accomplished by means of a hydraulic press. The pipe is heated in two zones. Preheating is accomplished in the straight part of the inductor without any material deformation or forming, while the bent inductor serves to heat the pipe to the desired final temperature. It is here that forming takes place. Heated to final temperature, the pipe is pushed over the mandrel by the press, and thus takes the shape of the mandrel. This method requires the mandrel to be heated before production starts, which is

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N ovember 2008

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