Evaluation and Improvement of Fatigue Behavior in Small Bore Piping Systems with A Metallurgical Approach

Vibration fatigue failure is a common integrity issue in small-diameter piping systems installed in industrial plants. In fact, many facilities are aware that these failures pose the highest integrity risk in steel piping systems and require a great deal of attention under operating conditions. Therefore, they follow common and up-to-date technical guidelines based on mechanical approaches to manage vibration fatigue damage. This study presents empirical estimates of vibration-induced fatigue damage in welded joints of small steel pipe systems using different steel materials and different weld filler metals, through a real experimental setup in which random mechanical vibrations are generated. The type of weld filler metal and the effects of the base metal on the fatigue strength of small-diameter piping systems, damage susceptibility, and fracture tendencies are compared with the metallurgical approach using experimental results.