QUANTITATIVE MEASUREMENT ON SAFETY INSTRUMENTED SYSTEM'S PERFORMANCE: AN APPROACH FOR INSURING A VIABILITY OF ANOTHER FLARE REDUCTION CHOICE

摘要

In order to avoid a catastrophic incident, the rigorous process industries use pressure relieving as an important (and, maybe, final) safeguard. So pressure release devices and flare capacity must be sized properly to accommodate any such significant contingency situation as global failure of cooling medium or electricity. The processes are often expanded, motivated by commercial reason and technology as well. However, expansion of pressure relieving system may not be possible at the same time due to different reasons. Instead, the experts have come up with an idea of eliminating the heat sources with an assistance of safety instrumented system (SIS). If SIS imported is proven to be reliable, additional pressure relieving capacity would not have to be considered. The target reliability of SIS is given based on best engineering data and experts' opinion and this paper shows how to model and quantitatively express our confidence in the SIS being designed.