Safety Valve Dynamic Instability: An Analysis of Chatter

Abstract

Safety valve chatter, which is characterized by violent oscillation of the disk or closure member, is a dynamical phenomenon representable by differential rather than algebraic equations. It is shown that the conditions necessary for avoiding chatter may be determined from the behavior of the differential equations in the region of certain critical points. The paper demonstrates how to determine these points and establish conditions necessary for avoiding chatter. The method is illustrated using a simple, but representative, gas-filled system. The results and their implications for safety valve design and selection are discussed, and a numerical example is given.