Use the Flush Zone Manager to create and manage parameters and characteristics for specific flush zones within a distribution system.  

Characteristics entered here are not part of the UDF simulation. UDF results are checked vs. these characteristics and a warning is generated if one or more constraint was violated during a sequence simulation.

UDF characteristics are specified to determine if flush sequences meet the desired values for pressures, velocities, and water volume. UDF does not attempt to modify characteristics when they are violated; UDF simply reports the features that do not meet the entered characteristics. You can use this information to develop a more rigorous flushing scheme.

Toolbar


 New Flush Zone - Select to create a new flush zone.

Insert Flush Zone - Select to create new flush zone above selected zone.

Create Zone Automatically - Select to automatically create zones based on regions determined in polygon layer.


Polygon Layer - Select the shapefile or feature class that represents the flush zones in the water system. This dataset must be contained in the ArcGIS table of contents to appear in the drop-down selection box.

Region ID Field - Select the field in the flush zone dataset containing unique ID's for each flush zone.

Searching Distance - Maximum searching distance. Use to show distance on map view.

Edit Flush Zone Description - Select to edit the description of an existing flush zone.

Delete Flush Zone - Select to delete the currently selected flush zone.

Save - Select to save the currently selected record.

 OK - Saves and additions or changes and closes the dialog box.

 Cancel - Closes the dialog box without saving any changes.

Flush Zones

All fields in the Flush Zone Manager must be populated. If certain flush zone characteristics are not important to the analysis, it is suggested that a very large number for maximum characteristics or a very small number for minimum characteristics be used.

ID - All flush zones are listed in this column.

Description - User-defined descriptions for each flush zones are listed in this column. To edit description, click on the icon in the Flush Zone Manager toolbar.

Flush Zone Characteristics

Minimum Flush Velocity - Enter the minimum desired velocity for Target Pipes in the flush zone during any one sequence within this flush zone.  This minimum flush velocity will be checked against the actual flush velocity calculated during a simulation.  If the model result does not exceed the entered characteristic, a warning will be generated.

Maximum Flush Volume - Enter the maximum total volume of water to be flushed out of the hydrant during any one sequence within this flush zone.  This maximum flush volume will be checked against the actual flush volume calculated during a simulation.  If the model result exceeds the entered characteristic, a warning will be generated. Enter 0 (zero) to ignore this characteristic.

Maximum Flush Length - Enter the maximum total length of pipe to be flushed during any one sequence within this flush zone.  This maximum flush length will be checked against the actual flush length calculated during a simulation.  If the model result exceeds the entered characteristic, a warning will be generated. Enter 0 (zero) to ignore this characteristic.

Minimum Residual Pressure - Enter the minimum residual pressure to be maintained at the hydrant being flushed during any one sequence within this flush zone.  This minimum residual pressure will be checked against the actual residual pressure calculated during a simulation.  If the model result does not exceed the entered characteristic, a warning will be generated.

Minimum System Pressure - Enter the minimum static pressure to be maintained at all nodes contained in the Flush Area during any one sequence within this flush zone.  This minimum static pressure will be checked against the actual static pressures calculated during a simulation.  If the model result of any junction in the flush area does not exceed the entered characteristic, a warning will be generated.

Minimum Shear Stress - The hydraulic shear stress at the pipe wall can also be used as a criterion for flushing. The minimum shear stress will be used as a parameter to determine a successful flushing routine. A successful simulation will result when the minimum shear stress value is met or exceeded. If the model result exceeds the entered characteristic, a warning will be generated. Enter 0 (zero) to ignore this characteristic

Flush Area - The selection set representing the flush zone consisting of any combination of network components.  Choose a selection set from the drop-down selection box or press to access the selection set editor. During a UDF simulation, the minimum system pressure is compared to the pressure calculated at each junction in the selection set defining the flush area.  Low pressure warnings will only be generated when low static pressure occurs at one or more junctions in this selection set; low pressures outside this selection set will not be considered.

Highlight Color - The color used to highlight a zone on the map. Click on the color box to choose an alternate color.

Highlight -   Click to highlight the currently selected flush zone on the map.

Reset -  Click to reset the map to the default display.

Closed Isolation Valves - All valves listed in this box will be remain closed for each flush sequence within the flush zone.