Pipe System Pressure Drop (Series Network) Calculator 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

t4-240

Effect

Computation or source lookup only

Input and validation requirements

A zero-diameter segment creates undefined area, velocity, and L/D terms. The calculator must reject it; accepting it without validation is a concrete failure mode. The branch test also exposes reliance on an unstated Reynolds-number friction-factor regime and threshold.

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": {
    "flow_rate_m3_s": 0.01,
    "rho_kg_m3": 1000,
    "elevation_change_m": 2,
    "g_m_s2": 9.81,
    "segments": [
      {
        "length_m": 20,
        "diameter_m": 0.1,
        "friction_factor": 0.02,
        "minor_loss_K": 1.5
      }
    ]
  },
  "expected_outputs": {
    "total_pressure_drop_Pa": 24078.13,
    "required_pump_head_m": 2.45445
  },
  "working": "Area=π(0.1²)/4=0.00785398 m². V=0.01/0.00785398=1.27324 m/s. Dynamic pressure=ρV²/2=1000(1.27324²)/2=810.569 Pa. Friction coefficient=fL/D=0.02(20/0.1)=4. Minor coefficient=1.5. Friction plus minor loss=(4+1.5)(810.569)=4458.13 Pa. Elevation term=1000(9.81)(2)=19620 Pa. Total=4458.13+19620=24078.13 Pa. Pump head=24078.13/(1000·9.81)=2.45445 m."
}

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-tranche4/tranche4-results.json