The following junctions have a predicted Sound Power Level greater than 155 dB

A Warning message in AFT Arrow

Note: This warning will only be shown when Sound Power Level is selected as an output parameter in Output Control.

Sound Power Level is calculated in the manner prescribed by the Energy Institute Guidelines for the Avoidance of Vibration Induced Fatigue Failure in Process PipeworkEnergy Institute, Guidelines for the Avoidance of Vibration Induced Fatigue Failure in Process Pipework, 2nd Edition, Energy Institute, London, UK, 2008..

The 155 dB threshold is important for its role in calculating Likelihood of Failure (LOF) due to high frequency acoustic excitation when using the method defined by the Energy Institute. When the PWL is greater than 155 dB, a user will need to determine whether the junction in question is a valve with low noise trim fitted. If so, the PWL will need to be corrected accordingly. When PWL at the source is greater than 155 dB, the LOF analysis proceeds with calculations of PWL at nearby welded discontinuities and mitigation efforts or changes to the process design may be in order.