IEC 61511: functional safety of safety instrumented systems for the process industry
Safety instrumented systems must bring a process to a safe state on demand, be independent of the basic process control system, and be designed, tested, and maintained to a specified integrity level.
Draft mapping. Drafted by the Register's agents from the rule's text and not yet confirmed by a person. It is the Register's reading, not legal advice: whether and how the rule applies to you is a question for counsel.
Controls this rule maps to
Required by the text The rule's text requires a measure that is this control, or plainly includes it. Implied A binding rule whose purpose needs this control, but whose text does not name it. The Register's reading. Recommended A voluntary standard or guidance recommends it; nothing binds you to it. Proposed Appears in a proposed rule or proposed provision that is not yet in force.
| Control | Strength | Where in the rule, and why | Confidence | Missing or failed in |
|---|---|---|---|---|
| Automated fail-safe C-R2 | Recommended | the safety instrumented system is the automated fail-safe (Triton: the plant tripped) | high | 2 cases |
| Physical safety interlock C-E4 | Recommended | physical safety interlock independent of the control layer | high | 1 case |
| Containment and isolation C-E5 | Recommended | independence from the basic process control system is a containment requirement | medium | 5 cases |
Cases that cite this rule
| Case | How the case cites it | Outcome |
|---|---|---|
| Triton 2017 | IEC 61511 (functional safety for process industries) | Stopped by the operator's control |