topic Re: Question about Subnetworks in Pressure Systems in ArcGIS Utility Network Questions

Question about Subnetworks in Pressure Systems

TSmith — Tue, 10 Feb 2026 00:27:25 GMT

Good Evening all,

I have been struggling to understand how subnetworks are defined in a pressure system. I have cleaned up all topology errors, and have tried setting both a PRV as a subnetwork controller for a pressure tier, as well as a pump station.

For the PRV, it works fine but traverses more of the system than it should. I have this same behavior with the pump station (High Pressure out set as controller) where it somehow loops back on itself.

Tried using a filter function barrier to understand where in the network it is somehow picking up the other pressure zone.

This looks fine, however we add a bit more pipe and I just get more confused.

There is a closed valve here in green (pressure boundary valve) that the UN is traversing as part of this trace.

I have fixed all pipes that were disconnected, ensured all boundary valves are connected and closed, I don't understand what I'm missing here. Ideally, the pump station would be the source for this newer higher pressure zone, the others are set by PRVs. I tried using a shortest path trace between this pump station and another point in the other pressure zone and got a "no path found" so what would ya'll recommend in terms of determining what is causing this behavior? I really appreciate the help!

Re: Question about Subnetworks in Pressure Systems

RobertKrisher — Tue, 10 Feb 2026 00:55:17 GMT

Look at the terminal connections for things like your pumps, boundary valves, and you may find that the pipes connected to that valve are all connected to the same terminals.

Re: Question about Subnetworks in Pressure Systems

gis_KIWI4 — Tue, 10 Feb 2026 01:08:30 GMT

@TSmith - What @RobertKrisher suggested and possibly another thing to check is the subnetwork definition and ensure that closed valves are set as barriers in the trace section of that tool.

Re: Question about Subnetworks in Pressure Systems

ErikRose — Tue, 10 Feb 2026 01:08:46 GMT

If you set one flag within the subnetwork, and another to a segment outside the network that is unintentionally connected, then trace the shortest path, this can narrow down the number of transition points you need to inspect.

Re: Question about Subnetworks in Pressure Systems

TSmith — Tue, 10 Feb 2026 14:31:52 GMT

This helped a lot- didn't think about that. Found a segment of pipe that was inadvertently connected when it shouldn't have been.

The subnetwork definition does stop at any closed valve, but it looks like there was a loop created by an inadvertent connection between the two pressure zones. Thanks for pointing me in the right direction!