Abstract: This study focuses on the assessment of fatigue damage in a piping system. Strain loading data was acquired using the fatigue data acquisition devices on a lab scale piping system. Specifically, the data was measured on the roughened and smooth pipe surfaces simultaneously, where the strain gauges were mounted on both of the piping surfaces. In this study, three different water flow rates were operated in the experiments which were normal, maximum and variable. The normal water flow rate was assumed as the reference flow rate for the subsequent fatigue analysis. The recorded strain signal was then analyzed using the frequency and time-frequency method and the short-time Fourier transform was applied to explain the fatigue damage events. The fatigue data from the experiment was employed to calculate the fatigue damage of the piping system.