‎ Defining a Fire Zone

A fire zone marks out a defined volume in which to consider the fire risk.

Detect3D uses two opposing points of a cuboid, as shown below, to define zones. The length, width and height of the zone will be calculated from the two selected point locations. As it is sometimes difficult to select a point with height in a 3D environment it is recommended to look from a 'top view' to select the length and width of the zone, ensuring it encompasses equipment or region for the analysis, then manually enter a z coordinate for the height.

Tutorial 1 - Figure 02 - indication of the two points used to define cuboid regions in Detect3D

For this tutorial a fire zone will be used. Zones can be defined with the following types:

• Fire Mapping - only generates coverage results for added flame detectors

• Gas Mapping - only generates coverage results for added gas detectors (point, open-path and acoustic)

• Both Fire and Gas Mapping - the default option which generates coverage results for any added device.

To add a Zone to your project:

1. Click the Add Item Tab and select Zone from the dropdown menu.

2. Set the Name of the fire zone to “Main Fire Zone”

3. Select Fire Mapping Only from the Type dropdown menu and leave the Risk Grade set to Default Grade.

4. For Point 1 enter in the coordinates ( 1, 1, 0 ) which will position the lower corner of the fire zone within the railing.

5. For the second defining point, click the arrow button next to the Point 2 coordinate text boxes to activate the Point Pick Tool. Select a point on the surface of the deck in the opposite corner of the platform from the origin, similar to Figure 03 below. Once selected, the coordinates will be recorded in the corresponding x, y and z text boxes. To match Figure 03, you may enter the following: ( 17, 20, 0 ).

6. Choose one of the points and change the z-coordinate to have a value of "4.5". This will give a height of 4.5 meters to the zone which will encompass the three vessels.

Tutorial 1 - Figure 03 - Second defining point shown by the yellow cross-hair of the Pick Tool

7. Leave the Type as Geographic: Point and the Resolution as Medium (0.25 m)

8. Note that the numerical value next to # Points: has changed once the two points for the fire zone have been selected. It is recommended to always keep this number below 300,000 unless you have a more powerful computer.

9. Click the Preview checkbox to view the defined fire zone and ensure that the red cuboid encompasses the three tanks in the middle of the module. Previewed items will appear transparent red in the viewport window.

10. Select the Add Item button to add the fire zone to the project items tree. Your 3D window should now appear similar to Figure 04 below.

Tutorial 1 - Figure 04 - 3D window showing the defined fire zone

Switch to the Project Items tab and notice that Main Fire Zone has been added under the Zones heading in the project items tree. Deselect the checkbox for Main Fire Zone in the Project Items Tree to turn off the visibility of the fire zone.