neqsim-trapped-liquid-fire-rupture

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" requires: java_packages: - neqsim.process.safety.rupture - neqsim.process.safety.inventory - neqsim.process.safety.release - neqsim.process.safety.barrier

Trapped-Liquid 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.

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.

Skills to Load Together

neqsim-stid-retriever for P&IDs/STIDs, 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
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
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:

{
  "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.

Java Calculation Pattern

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.

Results to Save

Save a trapped_liquid_fire_rupture section in results.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.

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 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