The Junction Demand Change Data screen is accessed by selecting a junction node and clicking on the Junction Change button in the Attribute Browser.

This screen allows you to select a curve to be used to change demand at a node during the Surge simulation. You can cause a transient event to be initiated by making a sudden increase or decrease in demand at a junction.

Note that if you have a junction selected and this icon appears as disabled, this indicates that this junction has already been configured as a Surge Protection Device. If you wish to change it back to an ordinary junction, then click the Surge Protection Device  button and click on the Purge button when the window appears. This will remove the surge protection device which will allow the demand change to be added.

Demand Change Curve - Where: X = Simulation Time, Y = Demand (in flow units)

Demand Change Curve

A change in the demand at a junction can produce a transient. This can be used to simulate a hydrant opening or any rapid change in demand. Select a demand change curve from the list of the predefined curves or use the Browse  button to open Curve Editor to create a new demand curve or to edit an existing demand curve.

Purge - Use the Purge button to remove any existing Demand Curve Data.

Create/Update - Enter any new or changed Demand Curve data and exit the Demand Change Data dialog box window.

Cancel - Cancels any new or changed Demand Curve data and closes the Junction Demand Change dialog box window.