Multidisciplinary approach pays off in condition assessment Laborelec’s Vibrations and Materials experts often join forces during damage assessments. This multidisciplinary approach enables to rapidly identify the root cause of a problem. This was clearly highlighted during two recent cases. Material fatigue at the root cause of vibrations At a large Belgian coal-fired power plant, the Laborelec Vibration Monitoring System was generating frequent alarms, particularly during full load operation. ‘Based on experience, we knew that there might be a link with a potential control valve default,’ says Koen De Bauw. ‘An inspection revealed that one of the valve rods was broken. Our Materials colleagues noticed that the choice of valve material was inappropriate. As a result, damage occurred due to high stress during operation.’ Vibration analysis confirms structural rotor deformation An overhaul at a Belgian natural gas-fired power plant revealed that metal fragments had melted and solidified on a rotor. Laborelec’s Materials experts determined that a thermal increase had appeared locally following excessive friction, causing a rotor deformation. Fabien Thielemans: ‘Our Vibrations colleagues confirmed these observations. Their measurements had shown unusually high vibrations on the shaft train. These vibrations were attributed to local friction in a sealed area.’       Contact: Koenraad DE BAUW P: +32 (0)2 382 0575