The dynamic behavior of a system constituted by a continuous stirred tank reactor (CSTR), where an esterification reaction takes place, coupled to a condenser which removes most of the heat of reaction, is studied. Dynamic simulation is used as a tool for checking the reliability of the safety valve on the condenser, which is designed according to the Fauske method. The sensitivity of the system behavior to different valve sizes is analyzed to point out, for a given set pressure of the valve, the proper size. It is proved that the best behavior of the relief system corresponds to the Fauske design.