A small teaching-scale water distribution network: one reservoir source feeding six junctions through a tree of pipes. Drag the demand sliders and the trunk-main diameter slider — flows, velocities, and residual pressures recompute instantly using conservation of mass plus simplified Hazen-Williams head loss. Click any pipe or node in the diagram for its calculation.
⚠️ Teaching approximation, not a certified design tool. This is a simplified branched (tree) network solved by straight mass-balance + Hazen-Williams head loss — not a full iterative EPANET-style hydraulic solver. It ignores looped-network flow splitting, minor (fitting/valve) losses, pumps, elevation-tank drawdown, fire-flow transients, and water-hammer effects. Use it to build intuition about how demand and pipe diameter drive velocity and pressure — not for real system design or capacity decisions.
Network Diagram
Pipe: normal (≤4 ft/s)Pipe: high (4–8 ft/s)Pipe: excessive (>8 ft/s)Node: ≥35 psiNode: 20–35 psiNode: <20 psi
Trunk Main Diameter
Pipe P1 — Reservoir → J112 in
Only this pipe's diameter is adjustable — it's the single biggest lever on system-wide pressure.
Junction Demands (gpm)
Selection Details
Click a pipe or a node in the diagram to see its calculation here.