Size and Wall Thickness Effect on Evaluation for Acoustically Induced Vibration (AIV)

Large acoustic energy generated by a pressure relief valve or blowdown system with large flowrate and pressure drop across it would result in fatigue failure of the piping system due to severe vibration at high frequencies. This phenomenon is called AIV (Acoustically Induced Vibration) and the evaluation method of AIV was first proposed by Carucci and Mueller in 1982. Since then some papers have suggested that there are several problems on the AIV evaluation method based on Carucci and Mueller works. However, essential change in the AIV evaluation method could not be achieved yet. This paper studies the effects of pipe diameter and wall thickness on AIV based on IEC noise evaluation method described in IEC 60534-8-3, 2010, since the pipe external noise which could be well estimated by the latest IEC method is proportional to the vibration stress of the pipe. The study results show that the key evaluation factor is the pipe wall thickness and the newly developed concept of the AIV evaluation method incorporating the pipe wall thickness shows good agreement with the other guidelines, FEA study results and AIV failure data.