Liquid pipeline pressure · screening twin
Marsden Point–Wiri · incompressible-liquid screening
Browser-only scenario. The 170 km length and nominal 250 mm pipeline are brief-supplied. Internal diameter defaults to an unverified 250 mm assumption; wall thickness and lining must be confirmed. No telemetry, pump command, approved operating limit or gas line-pack model is used.
Assumed steady-state pressure profile
- Algebraic pressure · DEMO
- Assumed delivery requirement
Elevation is spread linearly, not taken from a surveyed route. Negative calculated gauge pressure is a model warning, not a physically validated operating state; vapour pressure, column separation and transients are not solved.
Liquid contents are not emergency line-pack
Calculated from assumed internal cross-section × 170 km. Do not treat this as accessible stock or hours of post-trip supply. Isolation, product interfaces, minimum suction pressure and liquid compressibility are not modelled. Jet availability must come from releasable downstream storage and an approved response plan.
Open the Ruakākā disruption and storage-cover scenarioCalculation, exclusions and required verification
Darcy–Weisbach: Δp = f × (L/D) × ρv²/2; elevation pressure = ρgΔz; velocity = Q/A; g = 9.81 m/s². Pa ÷ 100,000 = bar. ML/day = m³/h × 24 ÷ 1,000. Defaults: 400 m³/h, 800 kg/m³, f = 0.018, 0 m rise, 60 barg inlet, 3 barg delivery. All except the brief route length are scenario assumptions, not approved limits.
Excludes viscosity-dependent friction, fittings, station losses, intermediate pumping, transient surge, thermal effects, vapour pressure, pump curves and multi-product interfaces. Before any change, the pipeline engineer must reconcile surveyed elevation and internal diameter, product temperature/viscosity, calibrated flow and pressure, station configuration and the approved pressure basis; retain a validated steady-state and surge assessment.
After an authorised duty change, compare synchronised pressure and flow measurements at the agreed rates and products with the approved model. The pipeline engineer must accept results against approved operating and transient limits before updating the operating envelope and inspection basis.