3 PERFORMING THE CONSEQUENCE ANALYSIS

Making sure the Run mode is set to Consequence

In the Phast product, the Home tab of the Ribbon Bar contains a Mode option, as shown. The calculations are performed in a particular sequence, and this option allows you to choose how far through the sequence you want the calculations to progress when you use the Run option.

The list of options for Mode will always include Discharge and Consequence. You select Discharge if you only want to run the discharge calculations, and Consequence if you want to proceed to the calculations of dispersion and hazardous effects after the discharge calculations are complete. In the illustration above, Mode is set to Consequence.

If you have a license for the 3D Explosion extension, there will be a third option called Effects, which uses the results of the calculations to perform an additional type of analysis. The Effects option will be set by default when you create a new workspace, but these calculations are not relevant to this tutorial and should not be run. Make sure you change the Mode to Consequence before you start the analysis.

Note: in Phast Lite the Run mode is always Consequence and there is no Mode option.

Defining the pressure vessel that contains a toxic material

Move to the Models tab section. You will start by defining the Pressure Vessel Equipment item that contains a toxic material.

The vessel is a sphere with a radius of 3.37 m and volume of 120 m3 and a maximum fill-level of 85%, containing chlorine at saturation conditions and ambient temperature. The sphere is located near the centre of the site and is elevated 4 m above the ground. There is no bund surrounding the sphere.

Turn on the option to insert Equipment on the GIS

In the Settings tab of the Ribbon Bar, check the option to Insert Equipment on GIS. By default this option is turned off, and when you insert an Equipment item the icon will appear immediately in the Study Tree. If you turn the option on, then the Equipment icon will not appear in the Study Tree until you have clicked on the GIS Input View to set the location for the Equipment item.

In this tutorial you will insert the Equipment items on the GIS View in approximately the correct location, and then correct the location as necessary in the input dialog.

Insert a Pressure Vessel Equipment item

Select the Study, then insert a Pressure vessel using either the right-click menu or the Insert gallery in the Home tab of the Ribbon Bar. The GIS Input View will become selected, the cursor will turn to crosshairs, and you should click at a point near the centre of the site as shown to place the Pressure Vessel.

After you have clicked, an icon will be added to the Study Tree, and a dot will appear in the GIS View to show the location of the Pressure Vessel.