Citation:
Date Published:
2022Abstract:
The Emergency Shutdown System (ESD) is a type of Safety Instrumented Systems (SIS) used to shut down the system in the event of anomalous conditions, it consists of sensors, logic solvers, and final elements. Reliability databases such as OREDA (Offshore and Onshore Reliability Data) and expert judgment indicate that Emergency Shutdown Valve (ESDV) failures are the most common cause of the unavailability of ESDs. Therefore, proper diagnostic is essential to prevent the failure risks of these valves. ESDV problems are of a different nature and difficult to treat with mathematical models because of their non-linear behavior, the imprecision of information, and the appearance of many failure modes that arise from many failure causes. Therefore, failure diagnostic mechanism based on heuristic knowledge of ESDV parameters must be established. In this paper, the problem of diagnosing ESDV failures is addressed based on the fault-symptom tree model and the Multiple Input-Multiple Output (MIMO) fuzzy inference system. The latter is built on a set of linguistic rules “if-then” provided by the fault-symptom tree model. the proposed approach was applied and verified on an ESDV subsystem in the petrochemical industry.