Process Skid Shutdown System
Corpus CompleteProject Summary
| Field | Detail |
|---|---|
| Application | Process skid with SIS / ESD (Emergency Shutdown) system |
| Industry | Process industry — oil and gas, chemicals, or similar |
| Safety standard | IEC 61511 (application) + IEC 61508 (foundation) |
| Corpus coverage | IEC 61511 and IEC 61508 functional-safety pages are present; IEC 60079 coverage is available for hazardous-area routing |
Important note: The local RAG corpus covers the IEC 61511 routing and lifecycle basics needed to place a process skid on the correct standards path. Project SIL calculations, proof-test intervals, and hazardous-area design details still need direct engineering verification against the published standards and the plant basis of design.
Starting Standards
| Standard | Role | Status |
|---|---|---|
| IEC 61511 2016 | SIS application standard for process industry | Complete |
| IEC 61508 2010 | Foundation safety lifecycle standard | Complete |
| NEC / local code | Electrical installation | Complete for US |
| IEC 60204-1 | Machine electrical (if machine elements present) | Complete |
Standards Decision Logic
Process skid with shutdown system:
├── IEC 61511 → SIS application standard (HAZOP → LOPA → SIL → SIF design)
├── IEC 61508 → Foundation lifecycle (referenced by IEC 61511)
├── IEC 60079 → If hazardous area (classified location)
└── NEC hazardous location articles → US installation
SIS Lifecycle Overview
Per IEC 61511, the SIS lifecycle includes:
- Hazard and risk analysis (HAZOP)
- Safety requirements specification
- SIL determination (LOPA or risk graph)
- Safety system design (SIF allocation)
- Installation and commissioning
- Operation and maintenance (proof testing)
- Decommissioning
Key Concepts
SIF (Safety Instrumented Function): A safety function implemented by the SIS. One SIS may have multiple SIFs, each with its own SIL target and proof test interval.
PFDavg (Average Probability of Failure on Demand): The key reliability metric for SIS/SIF. SIL target determines the required PFDavg range.
LOPA (Layer of Protection Analysis): Most common SIL determination method in process industry. Credits independent protection layers (IPLs) against the demand rate to determine required SIL.
Repository Paths
| Standard | Repository Path |
|---|---|
| IEC 61511 | rag/international/functional_safety/iec_61511/ |
| IEC 60079 | rag/international/hazardous_area/iec_60079/ |
| Scenario reference | rag/scenario/mini_machine_safety_design/ |
Limitations
- For SIL calculations, proof test intervals, and plant-specific SRS requirements, consult the published IEC 61511 standard and project procedures
- For classified locations, use the IEC 60079 family plus the applicable NEC hazardous-location articles and AHJ requirements
- This scenario does not cover API 670 (machinery protection) or other process-specific standards
See Petroleum / Oil & Gas industry overlay →
This site is a personal-use paraphrase and navigation reference for industrial automation standards. It is not a substitute for authoritative standards documents, professional engineering judgment, or legal review. All content is sourced from a local RAG corpus and has not been independently verified against current published editions.
Items marked TO VERIFY have limited or unconfirmed local coverage. Items marked NOT IN CORPUS are not covered in the local repository. Do not rely on this site for compliance determinations, safety-critical design decisions, or legal interpretation.