{
  "capability_id": "physics.fluid.npsh",
  "tool_id": "npsh",
  "engine": "npsh",
  "calculation_version": "1.0.0",
  "generated_at": "2026-11-10T05:18:41.923Z",
  "engine_build": "2026-09-17",
  "test_count": 14,
  "passed": 14,
  "failed": 0,
  "tests_summary": {
    "golden": {
      "passed": 2,
      "total": 2
    },
    "boundary": {
      "passed": 7,
      "total": 7
    },
    "property": {
      "passed": 5,
      "total": 5
    }
  },
  "engine_tested": true,
  "expert_reviewed": false,
  "internally_reviewed": false,
  "review_kind": null,
  "source_checked": true,
  "reviewed_by": null,
  "reviewer_role": null,
  "last_reviewed": null,
  "expert_review": {
    "status": "optional_not_performed",
    "reviewer": null,
    "scope": [
      "formula",
      "input semantics",
      "assumptions",
      "limitations",
      "sources",
      "tests"
    ],
    "note": "Domain expert review is optional under CVP (CVP-EXP-01). Absence does not block CVP Verified. See Review policy for supplemental domain assurance."
  },
  "internal_review": {
    "status": "not_applicable",
    "reviewer": null
  },
  "page": "https://www.calculatorx.com/calc/physics/npsh",
  "api": "https://www.calculatorx.com/api/v1/calc/npsh",
  "schema_input": "https://www.calculatorx.com/schemas/physics.fluid.npsh.input.json",
  "schema_output": "https://www.calculatorx.com/schemas/physics.fluid.npsh.output.json",
  "assumptions": [
    "NPSHa = (p_s − p_v)/(ρ g) + v_s²/(2g) + z_s; pressures absolute; SI",
    "Open tank: p_s=p_atm (default 101325 Pa), z_s=z−hf, v_s=0; hf is an input",
    "Not pump power, not orifice, not weir, not Q=Av, not Darcy, not a catalog NPSHr curve, not steam p_v(T)"
  ],
  "limitations": [
    "NPSHa = (p_s − p_v)/(ρ g) + v_s²/(2g) + z_s; pressures absolute; SI",
    "Open tank: p_s=p_atm (default 101325 Pa), z_s=z−hf, v_s=0; hf is an input",
    "Not pump power, not orifice, not weir, not Q=Av, not Darcy, not a catalog NPSHr curve, not steam p_v(T)"
  ],
  "boundary_conditions": [
    "missing p_v, or missing both p_s and z → MISSING_REQUIRED_INPUT",
    "margin mode without NPSHr → MISSING_REQUIRED_INPUT",
    "hf, v_s, p_v, or NPSHr < 0 → VALUE_OUT_OF_RANGE",
    "rho, g, or p_atm ≤ 0 → VALUE_MUST_BE_POSITIVE",
    "p_s with z/hf/p_atm, Q/H/P/η, C_d, A, L, f, or gauge pressure → MIXED_INPUT_ENCODING",
    "pump, orifice, weir, Manning, Darcy, or Q=Av as mode → INVALID_MODE"
  ],
  "sources": [
    {
      "title": "ISO 9906 — Rotodynamic pumps — Hydraulic performance acceptance tests",
      "section": "NPSH available at the pump datum",
      "url": "https://www.iso.org/standard/57605.html",
      "supports": "NPSHa from absolute suction pressure, vapor pressure, and velocity head",
      "kind": "standard"
    },
    {
      "title": "ANSI/HI 1.3 — Rotodynamic Pumps for Design and Application",
      "section": "NPSH available and required",
      "url": "https://www.pumps.org/",
      "supports": "NPSHa from suction-tank static head minus suction-line losses; NPSHr from the manufacturer",
      "kind": "standard"
    }
  ],
  "methods": [],
  "fingerprint": "sha256:d5b3082a766fb3f71a877c6f768057b8b8d12c7a39d98164672515b31dadfe70",
  "tier": "engine_tested",
  "verification": {
    "tests": {
      "passed": 14,
      "total": 14,
      "golden": 2,
      "boundary": 7,
      "property": 5
    },
    "contract_checks": {
      "passed": 6,
      "total": 6
    }
  },
  "evidence_core_generated_at": "2026-09-17T03:58:19.307Z",
  "rendered_at": "2026-11-10T05:18:41.923Z",
  "release_integrity": {
    "status": "verified",
    "scope": "workspace",
    "production_attestation_required": true,
    "calculation_version": "1.0.0",
    "artifacts": {
      "engine": "1.0.0",
      "page": "1.0.0",
      "capability": "1.0.0",
      "evidence": "1.0.0",
      "input_schema": "1.0.0",
      "output_schema": "1.0.0",
      "mcp_contract": "1.0.0"
    },
    "digests": {
      "input_schema_sha256": "4d99adcedf50829825531778ad1444c70c70aea4e5079b77a91f01e7814a4e34",
      "output_schema_sha256": "38d11ab23ad0d1d705d2d3d584e0fa3b4a702f6486b4eaa3ae638c46b13a9a24",
      "evidence_sha256": "c61db01d21b11529dcf16c338826ffbc58c36d1ba3e5e3ec53908e9e556401fb",
      "evidence_core_sha256": "c61db01d21b11529dcf16c338826ffbc58c36d1ba3e5e3ec53908e9e556401fb",
      "capability_sha256": "15f9e451a847696bb95ac6df0264ff4acc3c6576a26e30656de08382e94e2ac8",
      "engine_sha256": "c6ebd8436f08b413e1ac6317b2d48550f2e6639a90dff254244e3aa562158b8d",
      "mcp_contract_sha256": "eb3e39ad4a95ed263415b4932f185d5edfe00a2403267b7c5ed5f718d1ff6da3"
    },
    "contract_checks": {
      "total": 6,
      "passed": 6,
      "failed": 0,
      "items": [
        {
          "id": "release-artifacts-aligned",
          "status": "pass",
          "detail": "1.0.0"
        },
        {
          "id": "schema-output-required-declared",
          "status": "pass"
        },
        {
          "id": "schema-valid-input-executes",
          "status": "pass"
        },
        {
          "id": "engine-success-output-validates-schema",
          "status": "pass"
        },
        {
          "id": "schema-rejects-incomplete-input",
          "status": "pass"
        },
        {
          "id": "rest-success-payload-validates-schema",
          "status": "pass"
        }
      ]
    },
    "report": "https://www.calculatorx.com/.well-known/calculatorx-release-integrity.json"
  },
  "tests": [],
  "disclosure": {
    "policy": "calculatorx-public-evidence-v1",
    "full_validation": "private",
    "representation": "summary"
  }
}