Abstract
The stability was investigated for a safety valve mounted to a vessel through an inlet pipe by experiments and analysis. It was found that interaction between the pressure wave propagation through the inlet pipe and valve disc motion causes the instability. Longer inlet pipe could be stable due to the longer period of the propagation of the pressure wave and the attenuation effect of the mechanical friction of the safety valve. Stability analysis can explain the instability phenomena, however it cannot explain the stable condition with longer inlet pipe. Numerical simulation is effective to predict the stability for the longer inlet pipe.
