{
  "schema": "piping-caustic-regions/v1",
  "object_id": "c13-caustic-regions",
  "axes": {
    "x": "% NaOH; concentration convention unspecified",
    "x_domain": [
      0,
      50
    ],
    "y": "reachable pipe temperature, \u00b0C",
    "y_domain": [
      -10,
      130
    ]
  },
  "recovery": "Manual readings of original Figure10.1 at11 selected concentration columns; source line thickness/plot reading uncertainty \u00b12\u00b0C, concentration \u00b10.5 percentage point; extra intersample curvature error unquantified; polylines rendering only, no executable interpolation",
  "samples": [
    {
      "NaOH_percent": 0,
      "A_B_C_degC": 83,
      "B_C_C_degC": 99.5
    },
    {
      "NaOH_percent": 5,
      "A_B_C_degC": 82,
      "B_C_C_degC": 102
    },
    {
      "NaOH_percent": 10,
      "A_B_C_degC": 80,
      "B_C_C_degC": 104.5
    },
    {
      "NaOH_percent": 15,
      "A_B_C_degC": 76.5,
      "B_C_C_degC": 107.5
    },
    {
      "NaOH_percent": 20,
      "A_B_C_degC": 71.5,
      "B_C_C_degC": 110
    },
    {
      "NaOH_percent": 25,
      "A_B_C_degC": 66,
      "B_C_C_degC": 105
    },
    {
      "NaOH_percent": 30,
      "A_B_C_degC": 60.5,
      "B_C_C_degC": 97.5
    },
    {
      "NaOH_percent": 35,
      "A_B_C_degC": 56,
      "B_C_C_degC": 89
    },
    {
      "NaOH_percent": 40,
      "A_B_C_degC": 52.5,
      "B_C_C_degC": 82.5
    },
    {
      "NaOH_percent": 45,
      "A_B_C_degC": 50,
      "B_C_C_degC": 78
    },
    {
      "NaOH_percent": 50,
      "A_B_C_degC": 47.5,
      "B_C_C_degC": 76.5
    }
  ],
  "boundary_equality": "unresolved; do not assign exact boundary",
  "regions": {
    "A": "carbon steel; PWHT welds/attachments/cold-formed parts only if heat traced",
    "B": "carbon steel; PWHT welds/attachments/cold-formed parts",
    "C": "nickel alloys; no stated extra table requirement"
  },
  "requirements": {
    "A_untraced": "None means no listed additional table treatment, not overall eligibility",
    "A_traced_and_B": "PWHT including attachment welds and coldformedparts; avoid coldforming asfarpossible",
    "attachments": "complete before requiredPWHT",
    "supports": "not welded to pipe; insulation strip between support/pipe",
    "tracing": "avoid directwallcontacthotspots using specifiedspacers",
    "fabrication": "GTAW DN50andbelow/allrootpasslarger; selectedPWHTcoolingmax100C/h down350C and fullcycle record",
    "class": "actual external class/material/fabrication required"
  },
  "operational_hold": "Establish percent concentration convention and comparable adopted material/service basis before any selection; graphical boundary uncertainty doesnot establish physicalmodel validity"
}