![]() ![]() ![]() Hazards that can occur more frequently or that have more severe consequences will have higher SIL Levels.įigure 2: Safety Life Cycle model. ![]() SIL Level is a function of hazard frequency and hazard severity. To generalize how SIL Level is determined, see Figure 1. A higher SIL Level means a greater process hazard and a higher level of protection required from the SIS. IEC 61511: Safety Instrumented Systems for the Process Industry SectorĪs defined in the IEC standards, there are four SIL Levels (1-4).IEC 61508: Functional Safety of Electrical/Electronic/Programmable Electronic Safety-Related Systems.SIL is an acronym for “Safety Integrity Level” that comes from two voluntary standards used by plant owners/operators to quantify safety performance requirements for hazardous operations: This article serves as a high-level summary as to how SIL levels are determined for process applications. Each hazard that requires the use of an SIS must be assigned a target SIL level. Not all process hazards will require the use of a SIS. For each process hazard where the LOPA study concludes that existing protection cannot reduce risk to an acceptable or tolerable level, a Safety Instrumented System is required. A Layer of Protection Analysis (LOPA) is a method whereby all known process hazards and all known layers of protection are closely scrutinized. The SIS is one Protection Layer in a multi-layered safety approach since no single safety measure alone can eliminate risk. Safety Instrumented Systems (SIS) are installed in Process Plants to mitigate process hazards by taking the process to a “safe state” when predetermined set points have been exceeded or when safe operating conditions have been transgressed. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |