At the Goro Nickel mining plant in New Caledonia, one major supplier of machinery was frequently exchanging expensive compensators. It was clear that high vibrations were causing these unexpected costs; several solutions were tried but none of them resolved the problem. Ultimately, the pump manufacturer called VICODA, the specialist in vibration control to have a clear picture of the dynamic behaviour of the system and solve the problem definitely.
Two highly qualified technician travelled to New Caledonia to perform a measurement campaign with the aim to record not only the vibration amplitudes and accelerations with acceleration sensors, but also the displacements within the compensator (measured with laser distance sensors) and the stresses on the pipe (strain gauges) at different operating conditions. The measurements showed that the vibrations were above the limits prescribed by German standard for vibrations on piping systems (VDI 3842).
All recorded data was evaluated, determining the root cause of the problem: a resonance effect. The customer was highly satisfied with the final report and agreed to have also VICODA implement its recommendation. In order to reduce the vibrations and thus to bring the stress levels within the acceptable limits, VICODA supplied and installed 8 viscoelastic dampers. The devices, installed at the connection between compensator and piping system, solved the problem quite efficiently, reducing the vibration level by 30%.