TPi October 2011

Press dies from Schmolz + Bickenbach Guss

Maximum precision for the Nord Stream Baltic Sea pipeline

Pipes for the natural gas industry are subject to strict standards – the tolerances for deviations lie in the range of millimetres or even lower. A specialist in this field is Europipe GmbH. The company is a supplier in the market segment of large-diameter pipes for the oil and gas industry. One of the processes used by Europipe to bend sheets for the 18m long pipes into shape is the UOE process. Production for the Nord Stream Baltic Sea pipeline is currently in progress. The steel pipe specialist obtains the press dies required for this project for its O-press from Schmolz + Bickenbach Guss Group. The Europipe group, the head office of which is located in Mülheim an der Ruhr, Germany, and which has production sites in France, USA and Brazil, employs a total of approximately 1,700 staff. The core business of the company is the production of longitudinally and spiral-welded steel pipes for the oil and gas industry. “Our pipes are equally able to withstand the highest temperatures in the desert, the lowest temperatures in the eternal ice and the extreme pressure of the deep sea,” explained Dr Andreas Liessem, plant manager at the large-diameter pipe plant in Mülheim. The company is currently working on a large order for the natural gas industry: Europipe is producing the majority of longitudinally welded, large-diameter pipes for the Nord Stream pipeline from Vyborg, Russia, to Greifswald, Germany. New dimensions and new challenges The Nord Stream pipeline is the largest and most complex offshore project in the world at present. It comprises two pipelines, each of which is 1,220km long, and when it is completed it will feed over 55bn m 3 of natural gas from Russia

The casting specialist supplies press dies to Europipe for the production of pipes from 24" to 56"

into the European gas grid each year. Europipe is supplying around 153,500 pipes to Nord Stream in the context of two construction phases – this is equivalent to 1,838km with a total weight of around 1.6mn tonnes. “This is the largest order Europipe has ever undertaken,” stated Dr Liessem. For this project, the company is producing approximately 4,000 pipes per month with an external diameter of 1,220mm (48") and wall thicknesses between 26.8mm and 34.6mm using the UOE process (U-forming, O-forming, expanding). Here, a high-strength sheet, which also displays maximum toughness, is shaped into a ‘U’ on a U-press. After this, it is reshaped on the O-press using self-closing dies to form a slotted pipe. The longitudinal edges of the slotted pipe are then welded. The final, virtually circular, form is passed through an expander.

The 12m-long, longitudinally welded pipe is given coatings – inside in order to reduce friction between the gas and the pipe

wall and outside in order to prevent corrosion. After additional sheathing in concrete, the pipes are ready for laying. The pipes are transported by supply ships to the laying ship in the Baltic Sea, where they are welded into a pipe string and laid at water depths of up to 210m. They must withstand an operating pressure of up to 220 bar – a load that makes specific demands both on the material used and on the pipe production. Experience pays Jascha Alexander Jacobs, purchasing manager at Europipe provides a description:

On the laying ship, the pipes are welded into a pipe string and laid at water depths of up to 210m

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October 2011 Tube Products International