Steam Table Property Lookup implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t7-033

Effect

Computation or source lookup only

Input and validation requirements

The specification exposes two hard hazards: P=0 produces an undefined result and must be rejected, while the permitted P/T input does not define pressure units, absolute-versus-gauge convention, or quality at saturation. Consequently the same displayed input can select different regions or fail to determine unique h, s, v, u, and cp values.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "pressure_kPa": 101.325,
    "temperature_C": 100,
    "quality": 0,
    "state_specification": "saturated liquid"
  },
  "expected_outputs": {
    "h_kJ_per_kg": 419.04,
    "s_kJ_per_kg_K": 1.3072,
    "v_m3_per_kg": 0.001043,
    "u_kJ_per_kg": 418.9343,
    "cp_kJ_per_kg_K": 4.216,
    "phase_region": "saturation boundary, saturated liquid"
  },
  "reference_data": {
    "pressure_kPa": {
      "value": 101.325,
      "source_convention": "widely tabulated standard value; water saturation pressure at 100 C"
    },
    "temperature_C": {
      "value": 100,
      "source_convention": "widely tabulated standard value; normal boiling point of water at 101.325 kPa"
    },
    "hf_kJ_per_kg": {
      "value": 419.04,
      "source_convention": "IAPWS/IF97 standard steam-table value"
    },
    "sf_kJ_per_kg_K": {
      "value": 1.3072,
      "source_convention": "IAPWS/IF97 standard steam-table value"
    },
    "vf_m3_per_kg": {
      "value": 0.001043,
      "source_convention": "IAPWS/IF97 standard steam-table value"
    },
    "cp_liquid_kJ_per_kg_K": {
      "value": 4.216,
      "source_convention": "widely tabulated standard value near 100 C"
    }
  },
  "working": "At 100 C and 101.325 kPa, x=0 selects saturated liquid. h = hf = 419.04 kJ/kg. s = sf = 1.3072 kJ/(kg K). v = vf = 0.001043 m^3/kg. u = h - Pv = 419.04 - (101.325)(0.001043) = 419.04 - 0.105682 = 418.9343 kJ/kg. cp is reported from the liquid-property table as 4.216 kJ/(kg K). This is an exact normal-boiling-point table entry and an edge case at x=0."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche7/tranche7-results.json