Application guides
An application guide takes one real design task and works it end to end: what the physics actually is, which numbers decide the answer, what the solver reports back, and where the method stops being valid. It sits between a calculator, which answers a single question about a single pipe, and the Studio itself, which will solve whatever you draw but will not tell you what to draw.
Reach for a guide when you know the task but not yet the shape of the model. You have been asked to size an air main, specify lagging for a hot run, pick a pump, or hold a pressure across a distribution zone, and you want to see how the same problem has been framed before you start drawing. Each guide names the method it uses, links the verification case that checks that method against an independent reference, and ends with a worked example you can open and solve in your browser.
There are five. Three cover a design task with physics of its own - pump duty, heat loss, compressible air. The other two cover the network elements that are most often modelled wrongly, control valves and non-return valves, where the usual shortcut of treating them as a fixed loss gives an answer that is not slightly off but qualitatively wrong.
Which guide covers your task
Find the task you have. The row tells you the physics the guide solves, the numbers it is built to produce, and which plan the work sits on.
| Task | Governing physics | Key output | Plan |
|---|---|---|---|
| Confirm the non-return valves in a network genuinely block reverse flow | A two-state check-valve node - a plain minor loss in the allowed direction, exactly zero through-flow against it - resolved as an outer loop around the verified steady solver and cross-checked against OWA-EPANET 2.2 | Which valves sit open and which sit shut at the operating point, and the flow through each, instead of a loss-only fitting quietly passing flow backwards | Free |
| Size air mains and check delivery pressure and velocity before any pipe is ordered | Compressible isothermal flow solved in pressure-squared with the acceleration term and the Churchill friction factor, worked internally in absolute pressure, with fan curves scaled to inlet density and compressors as set-point machines | Pressure at every node, velocity in every branch with a configurable high-velocity advisory, fan operating point, and compressor discharge temperature and shaft power | Advanced |
| Work out the temperature a run delivers, and whether the insulation specified is enough | Hydraulics and heat transfer solved together: a Gnielinski or Dittus-Boelter inner film with a laminar fallback, composite-cylinder resistance through wall and lagging, an outside film to ambient, and an enthalpy balance where streams meet | Heat loss per pipe, delivered temperature down the run, the temperature of each insulation interface and of the outer surface, and the mixed temperature at a junction | Advanced |
| Model a distribution zone where valves have to hold a set-point, not just add a loss | The incompressible solve with a steady-state control law as an outer loop: PRV, PSV and FCV each pick regulating, fully open or shut as part of the solve, cross-checked against OWA-EPANET 2.2 | The state and through-flow of every valve at the operating point, with the held head or flow at each one that is regulating | Free |
| Choose a pump, and check it against the system it will actually run in | Incompressible network solve, with a least-squares fit through the catalogue head-flow points, the affinity laws for reduced speed, and Antoine vapour pressure for the suction check | Operating point where the pump curve crosses the system curve, efficiency there against the best-efficiency point, hydraulic and shaft power, and the NPSHa margin | Free |
Free means the incompressible-liquid solve, which runs in your browser with no account. Advanced is the paid plan that adds the compressible-gas and heat-transfer modes, at A$39 a month. The pricing section has the full split.
The five guides
Check valves and reverse flow
Model check valves that actually block reverse flow, not just add a loss. Non-return valves cross-checked against EPANET, with EPANET .inp import. Free in your browser.
Compressed air system design and pressure-drop analysis
Size compressed air mains and check pressure drop with a browser-based compressible-flow solver. Isothermal gas, fans, compressors. From A$39/month.
Pipe heat loss and temperature-drop analysis
Model pipe heat loss and temperature drop along a run in the browser. Gnielinski films, composite wall and insulation, solved with the hydraulics. From A$39/month.
Pressure-reducing-valve networks in the browser
Model pressure-reducing-valve networks in your browser. PRV, PSV and FCV control valves with a steady-state control law, cross-checked against EPANET. Free in your browser.
Pump system design and operating-point analysis
Find the pump operating point where the pump curve meets the system curve. Efficiency, BEP, shaft power, NPSHa and variable speed. Free in your browser.
Guides, calculators and examples
Three kinds of page do three different jobs, and picking the wrong one wastes time.
- A calculator answers one question about one pipe: a pressure drop, a velocity, a Reynolds number, a heat loss. No account, no drawing, seconds to an answer.
- An application guide frames a whole task and tells you how to model it, including the parts that are easy to get wrong. Read it once, then build.
- A worked example is a complete network you can open in the Studio and solve as it stands. Every guide points at the examples that demonstrate its physics, so you can go straight from reading to a running model.
What the guides do not cover
Every guide is steady state. There is no water hammer or surge analysis, no check-valve slam, no relief-valve sizing to a code, no pressure-breaker (PBV) valve, and no time-varying or rule-based control logic. Transient behaviour is a different class of problem and belongs in a dedicated surge package. Where a method has a limit that a particular network reaches - a gas line accelerating past the point where the isothermal assumption holds, for instance - the solver raises an advisory rather than quietly returning a number.
Fluid Network Studio computes steady-state pressures, flows, velocities, temperatures and power from the data you enter. It supports your engineering work rather than replacing it, results should be reviewed by a qualified engineer for the specific application, and no compliance with or certification against any particular standard is claimed.