Safety Systems Documentation

Documentation for safety-related features and systems in NeqSim.

Overview

This folder contains guides for implementing safety systems in process simulations, including Emergency Shutdown (ESD), High Integrity Pressure Protection Systems (HIPPS), blowdown analysis, and alarm management.

Documentation Index

Emergency Shutdown (ESD)

Document Description
ESD Dynamic Testing Workflow Dynamic ESD testing with process logic, OperationalTagMap/tagreader evidence, and JSON criteria reports
ESD_BLOWDOWN_SYSTEM.md Complete ESD and blowdown system guide
PRESSURE_MONITORING_ESD.md Pressure monitoring for ESD

HIPPS (High Integrity Pressure Protection)

Document Description
HIPPS_SUMMARY.md HIPPS overview and summary
hipps_implementation.md HIPPS implementation details
hipps_safety_logic.md HIPPS safety logic programming

Safety Architecture

Document Description
INTEGRATED_SAFETY_SYSTEMS.md Integrated safety systems overview
layered_safety_architecture.md Layered safety architecture (defense in depth)
sis_logic_implementation.md Safety Instrumented Systems (SIS) logic
integration_safety_chain_tests.md Safety chain integration testing
SAFETY_SIMULATION_ROADMAP.md Safety simulation development roadmap

Standards Compliance and Hazard Screening

Document Description
NOG 070 SIL, STS-0131 Gate and ESD Response Time Pre-determined SIL (NOG 070), aggregated STS-0131 acceptance gate, and IEC 61511 ESD response-time budget
API 14C SAFE Chart and NORSOK P-002 Compliance API RP 14C / ISO 10418 SAFE chart, NORSOK P-002 flare/blowdown/vent screening, and coupled multi-vessel blowdown header load
ISO 17776 MAH Bow-Tie and EI AVIFF FIV Screening Major-accident-hazard bow-tie from the ISO 17776 catalogue and Energy Institute AVIFF flow-induced-vibration screening
Flare Flame, Hazardous Area and PFP Demand API 537 flare flame/radiation/noise, IEC 60079-10-1 hazardous-area zoning, and API 521 passive-fire-protection demand
Automated HAZOP from STID and Simulation End-to-end STID/P&ID, plant data, NeqSim simulation, HAZOP, barrier, and report workflow
AI-HAZOP Input Data Format Required input-data format for a P&ID Safety Analyser / AI-HAZOP front-end: process model JSON, per-deviation runHazopScenario request, DEXPI design-conditions, limit-basis policy, and blocked-outlet overpressure screening
Open Drain Review with NeqSim Evidence NORSOK S-001 Clause 9 review using NeqSim-calculated liquid leak rate, firewater load, density, pressure, and drain capacity plus STID/tagreader evidence
Barrier Management and SCE Traceability Evidence-linked PSFs, SCEs, performance standards, and safety-analysis handoffs

Fire and Thermal Protection

Document Description
fire_blowdown_capabilities.md Fire case blowdown simulation
fire_heat_transfer_enhancements.md Fire heat transfer modeling
Vessel Thermomechanical Safety Transient non-equilibrium blowdown, fast filling, cryogenic boil-off, composite-wall conduction, and fire/blowdown wall rupture
Trapped Liquid Fire Rupture Blocked-in liquid segment fire rupture screening with material, flange, PFP, and source-term handoff
Blocked-In Liquid Thermal Expansion Isochoric pressure-rise screening (API 521 ยง4.4.12) for blocked-in liquid segments, independent of fire exposure

Relief Systems

Document Description
Trapped Inventory Calculator Evidence-linked trapped inventory for isolation, blowdown, flare-load, and MDMT screening
Trapped Liquid Fire Rupture Fire exposure, thermal expansion, pipe/flange failure screening, PFP demand, and source-term handoff
Blocked-In Liquid Thermal Expansion Isochoric pressure-rise screening and simplified beta/kappa relation for blocked-in liquid thermal relief screening
psv_dynamic_sizing_example.md Pressure Safety Valve dynamic sizing
Vessel Thermomechanical Safety Dynamic PSV sizing vs steady-state API 521 conservatism, plus blowdown, filling, boil-off, and rupture models
rupture_disk_dynamic_behavior.md Rupture disk dynamic behavior

Alarms

Document Description
alarm_system_guide.md Alarm system implementation guide
alarm_triggered_logic_example.md Alarm-triggered logic examples