Pressure-reducing-valve networks in the browser

Q: Does it import PRVs from an EPANET .inp file?

Yes. Control valves in an imported .inp come across with their control law intact, so a PRV imports as a regulating PRV rather than a fixed loss.

A pressure-reducing valve does not just add a loss: it holds a downstream pressure, switching between regulating, fully open and shut as the network around it changes. Getting that behaviour right is the difference between a distribution zone that holds its target pressure and one that does not. Fluid Network Studio models pressure-reducing-valve (PRV) networks in your browser, with a proper steady-state control law, and cross-checks the result against OWA-EPANET 2.2, the reference implementation.

It runs in a browser tab, with no desktop licence and no install. Control valves are part of the incompressible-liquid solve, available from the free Explorer tier.

Control valves that hold a set-point, not just a loss

Fluid Network Studio models four control valves as network nodes, each with its own control law:

PRV (pressure-reducing valve) holds a downstream pressure. When the upstream pressure is high enough it regulates, pinning the downstream head to its setting; when it is not, the valve is fully open; when holding the setting would need reverse flow, it shuts.
PSV (pressure-sustaining valve) holds an upstream pressure, the mirror image of a PRV.
FCV (flow-control valve) clamps the through-flow to a set-point.
Check valve passes flow one way and blocks reverse flow.

Each valve finds its own state (regulating, open or shut) as part of the solve, so a whole zone of interacting valves settles to a consistent operating point rather than being fixed by hand.

Cross-checked against EPANET

Control-valve logic is easy to get subtly wrong, so it is verified. On the verification page an active PRV pins its downstream head to the setting exactly and regulates the flow the downstream leg allows, an FCV clamps to its set-point, and a check valve passes forward flow as a plain fitting but carries exactly zero in reverse. Each case is solved live by the same solver the app runs and agrees with OWA-EPANET 2.2, the reference implementation of PRV, PSV and FCV logic, in the same global-gradient family. The valve law is solved as an outer loop around the verified steady solver, so a network with no control valve solves exactly as it did before.

Import an EPANET model with its valves intact

If you already have an EPANET .inp model, import it and its control valves come across with their control law: a PRV imports as a PRV holding its setting, not as a dead loss. That was not possible before, and it means an existing distribution model keeps behaving the way it was built to when you open it here.

What it does and does not do

Fluid Network Studio models the steady-state control-valve law and cross-checks it against EPANET. It does not size relief valves or PSVs to a code, automate fire-flow standards, model pressure-breaker (PBV) valves, or run dynamic, rule-based control logic (time-varying controls and rules). It supports your engineering work rather than replacing it; results should be reviewed by a qualified engineer for the specific application, and Fluid Network Studio does not claim compliance with any particular standard.

Frequently asked questions

Can it model a pressure-reducing valve that holds a downstream pressure?

Yes. A PRV node holds its downstream head to the setting when it can regulate, goes fully open when the upstream pressure is too low to reduce, and shuts when holding the setting would need reverse flow. The state is found as part of the solve.

Is the control-valve behaviour verified?

Yes. The verification page shows an active PRV, an FCV and a check valve solved live and cross-checked against OWA-EPANET 2.2, the reference implementation, in the same global-gradient family.

Does it import PRVs from an EPANET .inp file?

Yes. Control valves in an imported .inp come across with their control law intact, so a PRV imports as a regulating PRV rather than a fixed loss.

Does it size relief valves or run control rules?

No. It models the steady-state control-valve law. Relief-valve and PSV sizing to a code, pressure-breaker (PBV) valves, and dynamic rule-based control logic are out of scope.

Model your PRV network

The surest way to see how a zone of valves behaves is to draw it and solve it. Open the Studio, place your PRVs, PSVs, FCVs and check valves as nodes, set each one's target, and read the state and flow of every valve at once.

Open the Studio and model your pressure-reducing-valve network in your browser. Control valves are part of the incompressible-liquid solve, from the free Explorer tier.