Créé le : 27/09/2010 - Mis à jour le : 15/11/2012
Safety relief valves are devices designed to open when the pressure in the process to be protected exceeds the design pressure. However, in industrial practice, it often happens that the outlet of these valves are canalized through discharge lines which can be different from atmospheric, then there is a built up pressure generated by the flow in the piping which is superimposed to the back pressure in the discharge system. As a consequence, the initial sizing and selection of the safety relief valves, using results from tests conducted under conditions without back pressure are not necessarily valid. The manufacturers often use empirical rules of calculations to assess the performance characteristics in this type of use. When a safety relief valve is used with substantial back pressure (up to 30% of the set pressure), it is common practice to use a balanced construction...