v1.0.0 to v1.0.0
305 added, 10 removed. Audit A to A.
---
name: neqsim-trapped-liquid-fire-rupture
version: "1.0.0"
- description: "Trapped-liquid fire rupture study workflow for blocked-in liquid-filled pipe segments. USE WHEN: a task asks for trapped liquid, blocked-in liquid, thermal expansion rupture, fire exposure without relief, PFP demand, flange/pipe rupture screening, or generating a Word/HTML safety study from P&IDs, STID, line lists, piping specs, material certificates, and fire documents. Anchors on neqsim.process.safety.rupture plus trapped inventory, document retrieval, and source-term handoff."
- last_verified: "2026-05-10"
+ description: "Fire rupture study workflow for blocked-in liquid-filled pipe segments and blowdown pipe fire heat-up / time-to-rupture strain-rate screening. USE WHEN: a task asks for trapped liquid, blocked-in liquid, thermal expansion rupture, fire exposure without relief, PFP demand, flange/pipe rupture screening, supplied blowdown pressure profile, pipe wall heat-up, strain-rate rupture time, or generating a Word/HTML safety study from P&IDs, line lists, piping specifications, material certificates, and fire documents. Anchors on neqsim.process.safety.rupture plus trapped inventory, document retrieval, pressure-profile handoff, and source-term handoff."
+ last_verified: "2026-06-23"
requires:
java_packages:
- neqsim.process.safety.rupture
- neqsim.process.safety.inventory
- neqsim.process.safety.release
- neqsim.process.safety.barrier
---
- # Trapped-Liquid Fire Rupture Study
+ # Fire Rupture Study
- This skill coordinates the full study workflow for blocked-in liquid-filled
- segments exposed to fire: evidence retrieval, technical document extraction,
- trapped inventory calculation, fire heat input, temperature-dependent material
- strength, pipe/flange rupture screening, PFP demand, source-term handoff, and
- professional report output.
+ This skill coordinates two related fire-rupture workflows:
+ - blocked-in liquid-filled segments exposed to fire, where thermal expansion can
+ overpressure the pipe/flange system; and
+ - blowdown pipe segments exposed to fire, where a supplied pressure profile is
+ combined with wall heat-up, temperature-dependent material data, and a
+ Sellars-Tegart strain-rate model to estimate time to rupture.
+
+ For both workflows, gather evidence, preserve assumptions and gaps, run the
+ appropriate NeqSim safety.rupture calculation, hand off any rupture source term,
+ and produce a professional report output.
+
+ For source-document-driven blowdown pipe-fire studies, use the governed handoff
+ layer instead of calling the low-level solver directly: build
+ `SafetyEvidenceReference` entries, assemble a `PipeFireRuptureDataSource`, run
+ `PipeFireRuptureStudyRunner`, and report the returned
+ `PipeFireRuptureStudyHandoff`. This preserves calculation readiness, standards
+ readiness, deterministic uncertainty cases, and the post-rupture source-term
+ handoff in one JSON-safe package.
+
+ When the blowdown pressure profile has not yet been generated, first use the
+ dynamic flare/blowdown layer from `neqsim-depressurization-mdmt`: assemble
+ `LineEquipmentListEvidence` and `DynamicBlowdownFlareStudyDataSource`, run
+ `DynamicBlowdownFlareStudyRunner`, and use the returned source pressure profiles
+ and `dynamic_blowdown_flare_load_handoff.v1` as the governed basis for the
+ pipe-fire rupture profile and flare/consequence handoff.
+
Use the workflow generically. Do not encode operator-specific criteria in public
examples. If a private task has project-specific acceptance criteria, keep them
inside the task folder and cite the private basis only in that task deliverable.
## When to Use
- A Word report, technical note, or user request asks for a similar study on
trapped liquid, blocked-in liquid, or no pressure relief on liquid-filled piping.
- A fire case can heat a liquid-filled segment isolated by closed valves or PBB.
- Thermal expansion may raise pressure above pipe, flange, gasket, or relief limits.
- The study needs PFP endurance, rupture time, source-term handoff, or an evidence
matrix showing missing project data.
+ - A blowdown/depressurization pressure profile already exists and must be used
+ to screen pipe wall heat-up, accumulated strain, rupture time, and release rate.
+ - P&ID, line-list, and piping-specification data must be assembled into pipe cases and reviewed by
+ an engineer before calculation.
## Skills to Load Together
- - `neqsim-stid-retriever` for P&IDs/STIDs, line lists, piping specs, material
+ - Document-retrieval tools for P&IDs, line lists, piping specs, material
certificates, fire-zone/PFP documents, relief studies, and design basis documents.
- `neqsim-technical-document-reading` for structured extraction from Word, PDF,
Excel, P&ID images, line lists, and material certificates.
- `neqsim-process-safety` for barrier/PFP demand and risk register context.
- `neqsim-relief-flare-network` when a thermal relief path or PSV/flare load is
part of the mitigation.
- `neqsim-consequence-analysis` when the rupture source term must be carried into
dispersion, fire, explosion, or QRA calculations.
- `neqsim-professional-reporting` for the final evidence-based report.
## Evidence Retrieval Checklist
Before running the calculation, search the task references folder and any
configured document backend for:
| Evidence | Purpose in calculation |
|----------|------------------------|
- | P&ID / STID / isometric | Isolation boundary, valves, vents, drains, relief paths, line numbers |
+ | P&ID / isometric | Isolation boundary, valves, vents, drains, relief paths, line numbers |
| Line list / route table | NPS, internal diameter, wall thickness, length, design pressure/temperature |
| Piping specification | Material class, corrosion allowance, flange class, gasket/bolt family |
| Material certificate or material class sheet | SMYS, SMTS, grade, temperature limits, toughness notes |
| Flange/bolt/gasket data | Pressure-temperature rating and leakage/rupture limitations |
| Fire-zone / fire-study document | Exposed area, heat flux, pool/jet-fire basis, fire duration |
| PFP requirement or inspection record | Required endurance and actual protection condition |
| Relief/thermal relief/blowdown basis | Relief availability, set pressure, discharge path, creditability |
+ | Blowdown pressure profile | Time/pressure table, units, absolute/gauge convention, source calculation |
+ | Pipe fire material curve | Temperature-dependent UTS, strain effect, rupture strain limit, Sellars-Tegart constants |
+ | Pipe fluid basis | Fluid density, heat capacity, gas molecular weight, gas/liquid release basis |
| Design basis / technical requirements | Acceptance criteria, required margins, standards, reporting basis |
| Consequence or layout study | Source-term destination, escalation, radiation, dispersion context |
If any item is missing, do not invent it. Use a clearly labelled screening
default only when the result can still support a preliminary decision, and put
the gap in the assumptions/gaps register.
## Extraction Schema
Technical document readers should return a block like this to the solver:
```json
{
"study_type": "trapped_liquid_fire_rupture",
"segments": [
{
"segment_id": "TL-001",
"line_numbers": ["..."],
"isolation_boundary": {"upstream": "XV-...", "downstream": "XV-..."},
"fluid": {"description": "...", "composition_source": "..."},
"operating_pressure_bara": {"value": 10.0, "source": "..."},
"operating_temperature_C": {"value": 25.0, "source": "..."},
"pipe_internal_diameter_m": {"value": 0.10, "source": "..."},
"wall_thickness_m": {"value": 0.003, "source": "..."},
"exposed_length_m": {"value": 10.0, "source": "..."},
"material_grade": {"value": "API 5L X52", "source": "..."},
"flange_class": {"value": 900, "source": "..."},
"fire_basis": {"type": "api521_pool_fire", "heat_flux_W_m2": null, "source": "..."},
"pfp_requirement_s": {"value": 1800.0, "source": "..."},
"relief": {"available": false, "set_pressure_bara": null, "source": "..."},
"acceptance_criteria": [{"criterion": "...", "source": "..."}],
"evidence_gaps": ["..."]
}
]
}
```
Every numeric field should preserve original value, original unit, converted SI
value, source document, page/sheet, and confidence when available.
+ For blowdown pipe fire rupture, technical document readers or source-document agents
+ should return a block like this:
+
+ ```json
+ {
+ "study_type": "blowdown_pipe_fire_rupture",
+ "segment_id": "BD-001",
+ "pressure_profile": {
+ "time_unit": "minute",
+ "pressure_unit": "bara",
+ "basis": "absolute pressure profile from governed blowdown calculation",
+ "points": [[0.0, 61.3], [0.083333333, 59.7053]]
+ },
+ "pipes": [
+ {
+ "pipe_id": "3DD100",
+ "pipe_class": "DD100",
+ "nps_in": 3.0,
+ "outside_diameter_mm": 88.9,
+ "wall_thickness_mm": 3.7,
+ "corrosion_allowance_mm": 0.0,
+ "wall_undertolerance_fraction": 0.125,
+ "weld_factor": 1.0,
+ "material": "22Cr duplex",
+ "fluid_density_kg_m3": 23.75,
+ "fluid_heat_capacity_J_kgK": 2283.35,
+ "gas_molecular_weight_kg_kmol": 18.2,
+ "initial_temperature_C": 20.0,
+ "exposed_length_m": 1.0,
+ "source": "reviewed piping specification / workbook input"
+ }
+ ],
+ "fire_scenarios": ["Small jet fire 250 kW/m2", "Pool fire 250 kW/m2", "Large jet fire 350 kW/m2"],
+ "evidence_gaps": []
+ }
+ ```
+
+ ### Governed Source-Document Handoff Schema
+
+ When pipe data comes from source drawings and piping-specification rows, normalize it into a
+ source-traceable package before NeqSim calculation:
+
+ ```json
+ {
+ "schemaVersion": "pipe_fire_rupture_data_source.v1",
+ "studyId": "BD-001",
+ "input": {"segmentId": "3DD100", "evidenceReferences": []},
+ "material": {"materialName": "22Cr duplex"},
+ "scenario": {"name": "Large jet fire 350 kW/m2"},
+ "pressureProfile": {"pressureUnit": "bara", "timeUnit": "seconds"},
+ "pidTopologyEvidence": {
+ "schemaVersion": "pid_topology_evidence.v1",
+ "drawingId": "P-ID-001",
+ "revision": "A",
+ "simulationReady": false,
+ "boundaryVerified": false,
+ "nodes": [],
+ "edges": [],
+ "missingTags": []
+ },
+ "sourceDocumentEvidence": [],
+ "pipingSpecificationEvidence": [],
+ "processEvidence": [],
+ "fireScenarioEvidence": [],
+ "sourceDiagramsReviewed": true,
+ "pidTopologyVerified": false,
+ "pipingSpecificationRowsReviewed": true,
+ "materialCertificateReviewed": false,
+ "blowdownProfileVerified": true,
+ "fireScenarioReviewed": true,
+ "standardsReviewed": false,
+ "humanReviewRequired": true,
+ "readiness": {"verdict": "SCREENING"}
+ }
+ ```
+
+ Readiness semantics:
+
+ - `NOT_READY`: missing calculation-critical input (`input`, material, scenario,
+ or pressure profile). Do not run the calculation.
+ - `SCREENING`: calculation may run, but evidence gaps or unreviewed assumptions
+ prevent design-grade use.
+ - `DESIGN_GRADE`: controlled source drawing, piping-specification, material, fire, and depressurization evidence
+ has been reviewed and the package is ready for formal engineering review.
+
## Java Calculation Pattern
```java
SystemInterface oil = new SystemSrkEos(298.15, 10.0);
oil.addComponent("n-heptane", 100.0);
oil.setMixingRule("classic");
InventoryResult inventory = new TrappedInventoryCalculator()
.setFluid(oil)
.setOperatingConditions(10.0, "bara", 25.0, "C")
.addPipeSegment("TL-001", 0.10, 10.0, 1.0, null)
.calculate();
TrappedLiquidFireRuptureResult result = TrappedLiquidFireRuptureStudy.builder()
.segmentId("TL-001")
.fluid(oil)
.inventory(inventory)
.pipeGeometry(0.10, "m", 3.0, "mm", 10.0, "m")
.api5lMaterial("X52")
.fireScenario(FireExposureScenario.api521PoolFire(3.4, 1.0))
.flangeClass(900)
.timeControls(1800.0, 2.0)
.build()
.run();
```
Key classes:
- `MaterialStrengthCurve`: ambient SMYS/SMTS plus temperature derating.
- `FireExposureScenario`: API 521 pool fire, fixed heat flux, or radiative fire.
- `TrappedLiquidFireRuptureStudy`: transient pressure, wall temperature, pipe stress,
flange rating, vapor-pocket, relief-set, and rupture checks.
- `TrappedLiquidFireRuptureResult`: event times, time histories, JSON map, PFP demand,
and source-term handoff.
+ For supplied-pressure-profile blowdown pipe fire rupture:
+
+ ```java
+ BlowdownPressureProfile profile = BlowdownPressureProfile.fromMinutesAndBara(
+ new double[] {0.0, 0.083333333, 0.166666667},
+ new double[] {61.3, 59.7053, 58.6349});
+
+ PipeFireRuptureInput pipe = PipeFireRuptureInput.builder("3DD100")
+ .pipeClass("DD100")
+ .nominalDiameterInches(3.0)
+ .outsideDiameter(88.9, "mm")
+ .nominalWallThickness(3.7, "mm")
+ .corrosionAllowance(0.0, "mm")
+ .wallThicknessUndertoleranceFraction(0.125)
+ .weldFactor(1.0)
+ .fluidDensityKgPerM3(23.75)
+ .fluidHeatCapacityJPerKgK(2283.35)
+ .gasMolecularWeightKgPerKmol(18.2)
+ .initialTemperatureC(20.0)
+ .exposedLength(1.0, "m")
+ .build();
+
+ PipeFireRuptureResult pipeResult = PipeFireRuptureStudy
+ .builder(pipe, PipeFireRuptureMaterial.fromSpreadsheetMaterialName("22Cr duplex"),
+ PipeFireRuptureScenario.spreadsheetLargeJetFire(), profile)
+ .timeStepSeconds(5.0)
+ .maxTimeSeconds(1800.0)
+ .build()
+ .run();
+ ```
+
+ For governed agentic studies, prefer the runner pattern:
+
+ ```java
+ SafetyEvidenceReference pipingSpecWall = SafetyEvidenceReference
+ .builder("PIPING_SPEC", "nominal_wall_thickness_mm")
+ .documentId("pipe-class=DD100;rev=D")
+ .valueText("3.7")
+ .unit("mm")
+ .status("fetched_joined")
+ .confidence(0.95)
+ .build();
+
+ PipeFireRuptureInput governedPipe = pipe.toBuilder()
+ .evidenceReference(pipingSpecWall)
+ .build();
+
+ PipeFireRuptureDataSource dataSource = PipeFireRuptureDataSource.builder("BD-001")
+ .input(governedPipe)
+ .material(PipeFireRuptureMaterial.fromSpreadsheetMaterialName("22Cr duplex"))
+ .scenario(PipeFireRuptureScenario.spreadsheetLargeJetFire())
+ .pressureProfile(profile)
+ .addPipingSpecificationEvidence(pipingSpecWall)
+ .sourceDiagramsReviewed(true)
+ .pidTopologyVerified(false)
+ .pipingSpecificationRowsReviewed(true)
+ .materialCertificateReviewed(false)
+ .blowdownProfileVerified(true)
+ .fireScenarioReviewed(true)
+ .standardsReviewed(false)
+ .build();
+
+ PipeFireRuptureStudyHandoff handoff = PipeFireRuptureStudyRunner.builder()
+ .timeStepSeconds(5.0)
+ .maxTimeSeconds(1800.0)
+ .runUncertainty(true)
+ .build()
+ .run(dataSource);
+ ```
+
+ Key pipe-fire classes:
+
+ - `BlowdownPressureProfile`: absolute pressure profile with exact tabulated-point lookup, step or linear mode, and barg conversion.
+ - `PipeFireRuptureInput`: one pipe case with geometry, wall allowance, fluid, and exposed-length data.
+ - `PipeFireRuptureMaterial`: workbook-style material curves for 22Cr duplex, SS316, CS235, CS360/API 5L-X52, superduplex, and 6Mo.
+ - `PipeFireRuptureScenario`: small jet, pool fire, large jet, and custom radiative plus convective fire exposure.
+ - `PipeFireRuptureStudy`: heat-up, thick-wall stress, Sellars-Tegart strain rate, accumulated strain, rupture event, and screening release estimate.
+ - `PipeFireRuptureResult`: time series, rupture summary, warnings, recommendations, release estimate, and JSON map.
+ - `SafetyEvidenceReference`: compact source reference for source drawings, piping specifications, process, fire, and material inputs.
+ - `SafetyStudyReadiness`: `NOT_READY` / `SCREENING` / `DESIGN_GRADE` verdict with findings and actions.
+ - `PidTopologyEvidence`: typed P&ID topology graph, boundary status, missing-tag register, and drawing-overlay readiness.
+ - `PipeFireRuptureDataSource`: governed data-source package binding inputs to evidence and review flags.
+ - `PipeFireRuptureStudyRunner`: readiness-gated orchestration of solver, standards check, uncertainty, and source-term handoff.
+ - `PipeFireRuptureStudyHandoff`: versioned package containing data source, readiness, result, uncertainty, and source term.
+ - `PipeFireRuptureStandardsValidator`: API 521 / ISO 23251 / NORSOK S-001 / piping-specification evidence-quality gate.
+ - `PipeFireRuptureUncertaintyRunner`: deterministic one-at-a-time perturbation screening of wall, corrosion, heat-flux, and initial-temperature assumptions.
+ - `LineEquipmentListEvidence`, `DynamicBlowdownFlareStudyDataSource`, `DynamicBlowdownFlareStudyRunner`, and
+ `DynamicBlowdownFlareStudyHandoff`: governed dynamic depressurization, PSV, and flare-load setup used to create a
+ source-traceable pressure profile before pipe-fire rupture screening.
+
+ ## Reusable Safety Report Template
+
+ For governed source-document pipe-fire studies, the Word/HTML report should use a
+ repeatable evidence-first structure. At minimum include:
+
+ 1. **Executive verdict** with `NOT_READY`, `SCREENING`, or `DESIGN_GRADE`, plus
+ the human-review status.
+ 2. **Evidence matrix** with source system, document id, revision, page/sheet,
+ field, extracted value, unit, status, confidence, and notes.
+ 3. **Source drawing table** with drawing id, revision, embedded-text/OCR
+ status, topology nodes/edges count, missing tags, and overlay/annotation link.
+ 4. **Piping specification table** with applicable revision, class/material references, NPS,
+ outside diameter, wall thickness, corrosion allowance, undertolerance, and
+ row-review status.
+ 5. **NeqSim input lineage** mapping each solver input to its `SafetyEvidenceReference`.
+ 6. **Standards-applied table** covering API 521 / ISO 23251, NORSOK S-001,
+ piping/material basis, and consequence/source-term handoff status.
+ 7. **Assumptions and gaps register** with severity, effect on result, and required
+ action before design use.
+ 8. **Calculation results and uncertainty** including rupture time, rupture pressure,
+ wall temperature, release estimate, deterministic perturbation cases, and
+ P10/P50/P90 where available.
+ 9. **Source-term handoff** using `pipe_fire_rupture_source_term_handoff.v1` when
+ rupture is predicted.
+ 10. **Calculation lineage** from document field to NeqSim input to reported result.
+
+ Before the report is considered complete, apply these hard QA gates:
+
+ - The executive summary and problem description must be populated from the
+ current `task_spec.md` and `results.json`; no placeholder text may remain.
+ - The report front page must state the readiness label (`NOT_READY`,
+ `SCREENING`, or `DESIGN_GRADE`) and whether design-grade use is blocked.
+ - The method in `task_spec.md`, source scripts, generated `results.json`, and
+ report must agree on the pressure-profile basis. If the task moved from a
+ reconstructed profile to a direct dynamic NeqSim profile, update all four.
+ - Script-backed studies are acceptable when `study_config.yaml` explicitly sets
+ notebooks to not required; do not create false notebook execution warnings.
+ - `analysis.md` and `neqsim_improvements.md` must be filled for safety-critical
+ workflow/code gaps, including reporting, evidence-readiness, pressure-profile
+ export, plant-data evidence, and governed handoff gaps.
+ - The evidence gaps/design blockers and recommendations must appear before or
+ alongside the conclusions, not only in appendix-style detail.
+
## Results to Save
Save a `trapped_liquid_fire_rupture` section in `results.json`:
```json
{
"trapped_liquid_fire_rupture": {
"segments": [
{
"segment_id": "TL-001",
"limiting_failure_mode": "PIPE_RUPTURE",
"time_to_pipe_rupture_s": 420.0,
"time_to_flange_failure_s": null,
"minimum_failure_time_s": 420.0,
"final_pressure_bara": 145.0,
"final_wall_temperature_C": 530.0,
"pfp_required_endurance_s": 1800.0,
"pfp_margin_s": -1380.0,
"evidence_gaps": ["Material certificate not found"],
"recommendations": ["Provide thermal relief or documented PFP upgrade"]
}
],
"standards_applied": ["API 521", "ISO 23251", "ASME B31.3", "ASME B16.5"],
"assumptions": ["Generic API 5L X52 screening curve used pending certificate"],
"evidence_matrix": []
}
}
```
For Standard/Comprehensive studies, include:
- Segment summary table with event times and limiting mode.
- Evidence matrix with document, page/sheet, extracted value, confidence, and gap status.
- Assumptions/gaps register ranked by impact.
- Time histories for pressure, wall temperature, material allowable stress, and flange rating.
- PFP demand table from `toPassiveFireProtectionDemand(...)`.
- Source-term handoff from `createRuptureSourceTerm(...)` if rupture is predicted.
- Risk register using `neqsim-process-safety` when consequences are material.
+ For blowdown pipe fire rupture, save a `pipe_fire_rupture` section in
+ `results.json`:
+
+ ```json
+ {
+ "pipe_fire_rupture": {
+ "segment_id": "BD-001",
+ "pressure_profile_basis": "absolute bara profile from governed blowdown model",
+ "pipes": [
+ {
+ "pipe_id": "3DD100",
+ "fire_scenario": "Large jet fire 350 kW/m2",
+ "rupture_predicted": true,
+ "time_to_rupture_s": 110.0,
+ "rupture_pressure_barg": 32.03,
+ "rupture_wall_temperature_C": 760.0,
+ "release_estimate_kg_s": 21.9,
+ "evidence_gaps": []
+ }
+ ],
+ "standards_applied": ["API 521", "ASME B31.3"],
+ "assumptions": ["Spreadsheet material curve used pending certificate review"]
+ }
+ }
+ ```
+
+ For governed studies, also persist the runner handoff:
+
+ ```json
+ {
+ "pipe_fire_rupture_handoff": {
+ "schemaVersion": "pipe_fire_rupture_study_handoff.v1",
+ "calculationReadiness": {"verdict": "SCREENING"},
+ "standardsReadiness": {"verdict": "SCREENING"},
+ "result": {},
+ "uncertainty": {"schemaVersion": "pipe_fire_rupture_uncertainty.v1"},
+ "sourceTermHandoff": {"schemaVersion": "pipe_fire_rupture_source_term_handoff.v1"}
+ }
+ }
+ ```
+
## Validation and Benchmarking
- Hand-check pressure rise using `deltaP = bulk_modulus * alpha * deltaT`.
- Compare API 521 heat flux or heat input against an independent spreadsheet or standard example.
- Verify material ambient strength against pipe specification or certificate.
+ - For pipe-fire studies, benchmark one representative case against the source
+ workbook or an independent spreadsheet before scaling to all pipe cases.
+ - Verify pressure-profile absolute/gauge convention. The workbook-style stress
+ and release calculations use barg, while the pressure profile is often supplied
+ as bara and converted by subtracting 1 bar.
- For high-consequence segments, treat the NeqSim result as screening and recommend
specialist flange/gasket assessment, FEA, or consequence modelling as needed.
## Common Mistakes
| Mistake | Fix |
|---------|-----|
| Using a generic flange class as final proof | Replace with project flange, bolt, and gasket pressure-temperature data |
| Crediting relief without a discharge path | Verify relief/thermal relief path on P&ID and relief design basis |
| Ignoring vents/drains | Include them in the isolation boundary and trapped-volume assessment |
| Assuming PFP is installed and intact | Require PFP specification and inspection/condition evidence |
| Reporting only rupture time | Also report assumptions, evidence gaps, PFP margin, and source-term consequence handoff |
+ | Treating pressure-profile units casually | Record whether the profile is bara or barg and convert explicitly |
+ | Letting superduplex map to 22Cr duplex | Use `PipeFireRuptureMaterial.fromSpreadsheetMaterialName` or a reviewed material curve |
+ | Running plant-wide pipe-fire cases without review | Ask the engineer to verify source-document, piping-specification, and user overrides before calculation |
## Related Documentation
- `docs/safety/trapped_liquid_fire_rupture.md`
- `docs/safety/trapped_inventory_calculator.md`