The step by step approach for F&G Mapping study is given below:
This involves building up a model which gives the process data (vessel and pipe substances, pressures and temperatures and locations). This can be the same data that is used for the risk assessment. To this must be added vessel elevations and heights, and inter unit pipe routing, to allow for full 3D modelling. These are transferred to the GIS model for the analysis.
This involves defining the location, direction (for the fire detectors), path (for open path detectors), and detection thresholds (from the instrument specifications). These are transferred to the GIS model for the analysis.
For gas clouds, a check is made to determine whether it is detected by one, two or more detectors. For fires, a check is made to determine whether each fire is within the detection zone of one or more detectors.
The impact of moving, adding and removing sensors is investigated for the more likely design improvements.
The range and aperture angle of the detectors is obtained from manufacturer specifications and is plotted on a 3D plot of the plant.