RotaBolts Eliminate Expensive Plant Shutdowns For Shutdown

One of the world's leading manufacturers of paper and board products, Stora Billerud of Sweden, has installed Rotabolt tension control fasteners to eliminate expensive leaks from a high-pressure continuous digester.

Stora is claimed to be the oldest company in the world.  For over 800 years, the company was heavily involved in mining and, since 1900, has steadily expanded its operations within various wood-based industries.  Today, Stora produces a wide range of paper and board products including paper and fluff pulp, newsprint and magazine paper, carbonized paper and thermal paper.

At the heart of the company's manufacturing process lies a high-pressure pre-impregnation vessel linked to a kamyr continuous digester.  The pre-impregnation vessel, which operates at a pressure of 14 bar and at 160 degrees, its situated outdoors and has to withstand temperatures ranging from -30 degrees to +30 degrees C.  In the past, these operating conditions led to breakdowns in the vessels bolted joints and resultant, expensive leaks.  However, since the fitment of Rotabolt tension control fasteners, leaks have been eliminated and the complete production process is now much more efficient.

Repeated plant shutdowns due to joint failures were costing Stora approximately $6000 per hour but 56 RotaBolts have been installed on each joint at a lower cost than sealing a single failed joint using traditional methods.  Also the RotaBolts"fingertip" checkability means quick and simple, regular inspection of all bolts.  Consequently, any loose bolts are immediately tightened to the correct tension with no interruption to the operation of the plant.

Commenting on the success of the RotaBolts, Stora project maintenance engineer, Kjell Wester, "We are delighted with the performance of the Rotabolt system.  The bolts have eliminated leaks, are easy to check and operate well in all other weather conditions.  From a maintenance point of view, they have solved a very serious problem for us".

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