Hydraulic calculations

1. Give it a supply

Place a water supply ball (Ctrl+Shift+W) where the supply enters, and edit its curve — static, residual and flow from the flow test. If there is a pump, place a fire pump element (Ctrl+Shift+P) and right-click it to Adjust pump curve…. Flip pump reverses suction and discharge if you drew it the other way round.

2. Draw the remote area

Pick the remote-area tool from the HYDRAULICS group and outline the area. The boundary snaps to the midline between heads, so it lands where a reviewer expects it rather than through a sprinkler.

• Inclusion can be by plan area, by an elevation range, or by name — useful when several systems overlap in plan.
• Right-click a placed boundary for its live hydraulic report, its printed reports, Edit Boundary Here…, and delete.
• You can have several remote areas in one project and calculate them independently.

3. Decide which heads flow

Every sprinkler carries its own flow setting, and every part of the program — the remote-area calc, the project-wide preview, and the printed report — resolves it the same way, so they cannot disagree.

• Automatic (the default, and what every older project loads as) — the head flows only when it is inside the remote area being calculated.
• Open — it always flows, anywhere on the drawing, in every area's calculation.
• Closed — it never flows, even inside the remote area. A closed head produces no demand at all, so it also drops out of the report and off the node tags.

A head can also carry a minimum to flow — either a minimum psi or a minimum gpm, never both (if both somehow get set, psi wins). A minimum is a floor on a head that is already flowing; it never turns a dry head on. Flow and pressure stay tied through the head's K-factor, the same way the NFPA 13 7 psi minimum operating pressure is applied.

Set it from the sprinkler's Properties panel, or right-click in the drawing → Set Flow → Open / Closed / Automatic / Minimum to Flow… / Clear minimum. Either route works on a whole multi-selection in one undo and keeps your selection.

A project with no remote area has nothing to scope to, so it flows every head that has demand, minus the closed ones.

4. Run it

• Leave the Live pill on and the calculation re-runs after every edit.
• Turn it off to draft at full speed, then right-click any object → Run Hydraulic Calculation when you want numbers. Turning Live back on catches up immediately.
• Right-click → Open Live Hydraulic Preview overlays demand against the supply curve, so you can watch a change move the point.

5. Read the results

The Analysis tab in the side panel carries the whole answer:

• Calc — the calculation itself.
• Demand — what the system is asking for.
• Nodes, Links, Runs — the model the solver built from your drawing, node by node.
• Remote Areas — each area and its result.
• Warnings — anything the solver is unhappy about. Read this before you trust a number.

View → Hydraulic Node Tags puts the node numbers on the plan in hex tags — prefix, starting number, size and colour are all settable, they can carry leader lines, and you can drag them clear of your linework.

Friction losses

Valves and flex drops carry their own losses, entered as an equivalent length or a custom curve. A flex drop's loss is on its right-click menu alongside its length.

Printing the calc

• Reports → Hydraulic Calc Package (HTML)… — the full package.
• Reports → Print All Remote Area Calcs (PDF)… or Print Selected….
• The Water Supply Curve Report button in the FILE toolbar group.
• Tools → NFPA 1142 Water Supply Calculator… for the rural water-supply case.

The printed layout is being matched to the calc report format reviewers already know.