{
  "representation": "authored illustrative one-pass boundary model; not literal A/B pass splice or operating lineup",
  "physical_object": "same process tube pass in both comparisons",
  "states": [
    {
      "id": "production",
      "connections": [
        {
          "pass_end": "normal inlet end",
          "joined_to": "normal process inlet",
          "connector": "removable piece"
        },
        {
          "pass_end": "normal outlet end",
          "joined_to": "normal process outlet",
          "connector": "removable piece"
        }
      ]
    },
    {
      "id": "intervention",
      "connections": [
        {
          "pass_end": "normal inlet end",
          "joined_to": "selected temporary end interface"
        },
        {
          "pass_end": "normal outlet end",
          "joined_to": "selected temporary end interface"
        }
      ],
      "normal_process_pipes": "disconnected at identified joints; remaining ends have specified closure boundaries",
      "released_connectors": "handling/removal disposition identified; no movement sequence shown"
    }
  ],
  "access": [
    "header-box removable panel",
    "tube-header plug/tool approach",
    "personnel entry"
  ],
  "restoration": [
    "normal process route and joints",
    "connector position/orientation",
    "closure checks",
    "remaining supports",
    "work access and protection"
  ],
  "excluded": [
    "isolation effectiveness claim",
    "steam/air utility distribution",
    "control lineup",
    "quench/discharge circuit",
    "adjacent pass operating permission"
  ]
}