Modeling the vibrations of small bore piping systems

Several failures of small bore piping systems occurred in the French nuclear power plant in the past years because of fatigue due to flow-induced vibrations. The analysis of the failures as well as the design of new small pipes require a fair comprehension of their vibrational behavior. An analytical approach of the vibrations of a straight small bore piping system is presented and compared to experimental measurements, completing the results of two former papers. The influence of the valve geometry, the run pipe shell stiffness and the tubing influence are pointed out. Easy to use criteria are provided for the design engineer.