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Abstract Objectives/Scope An Acoustic Induced Vibration risk was identified at a relief valve outlet, exceeding the acceptance criteria as per Energy Institute Guideline. The risk was overlooked due to an input error to the flow rate in the engineering stage. This presents a risk of fatigue induced failure on a weldolet located approximately 1 m away from the relief valve. The team subsequently explored a time-based approach to ensure fatigue failure risk is tolerable. Methods, Procedures, Process A time-based assessment was explored to demonstrate that fatigue failure risk is tolerable within 14 weeks period, by: 1) Calculating the number of cycles to failure from Energy Institute Guidelines for the Avoidance of Vibration Induced Fatigue Failure in Process Pipework 2) Calculating the excitation frequency based on IEC 60534-8-3: Industrial-process control valves - Part 8-3:Noise considerations - Control valve aerodynamic noise prediction method 3) Determining number of relief events to failure, based on full flow relief of 30 minutes per event, taking into account operation interventions to reduce or stop flow within specified duration Results, Observations, Conclusions The risk was only present for 14 weeks as the relief valve mass flow would be reduced due to installation of Instrument Protective Function (IPF) upstream of the relief valve. The number of relief events to cause the fatigue failure was calculated to be 8 events, based on the calculated no of cycles to failure and excitation frequency of 25 million cycles and 1569 Hz respectively. This risk was determined to be tolerable (ALARP) when comparing to the historical relief events observed in the plant. Additional mitigation proposed was to evaluate the integrity and operating conditions in the case of one relief scenarios. The IPF system has since been implemented and there has been no relief event ever since. Novel/Additive Information Typically, Acoustic Induced Vibration will depend fully on Energy Institute Guideline and modification will be required in this case as the Likelihood of Failure (LOF = 0.88) was beyond the acceptance criteria (LOF = 0.3). The team has gone beyond the guideline, by combining the result with IEC 60534-8-3 to determine the probability of failure within the 14 weeks of exposure.