Flowpath Engineering Portal

Pressure Flow Between Reservoirs — Pipe Hydraulics Calculator

Calculate pressure-driven pipe flow between two reservoirs using Darcy-Weisbach and Colebrook-White equations. Determine flow rate, head loss, and optimal pipe sizing.

What this tool does

Darcy-Weisbach Analysis

Calculate friction losses in pressurised pipelines using the Darcy-Weisbach equation with automatic friction factor determination.

Colebrook-White Solver

Iteratively solve the Colebrook-White equation for friction factor across all flow regimes from laminar to fully turbulent.

Pipe Sizing & Selection

Determine required pipe diameter for a given flow rate, or calculate achievable flow for a given pipe size and head difference.

Minor Loss Coefficients

Account for fittings, bends, valves, and other minor losses in the total head loss calculation for realistic pipeline design.

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Open Pressure Flow Calculator

Part of the Flowpath Engineering suite of free civil engineering tools for New Zealand.