Fire Flow Analysis

Analysis will be performed in as many steps as there are hydrants in the model:

1. In each step, one of the hydrants will be considered main hydrant and active. Step will be named after that hydrant. Example: Hydrant [1], Hydrant [2], …      

2. If fire-risk category requires more than one hydrant to be active at the time, surrounding hydrants will be also activated. Example: Built-in Moderate-risk category requires four hydrants to discharge simultaneously, so three surrounding hydrants will be activated in addition to the main one.     

3. Procedure will store minimum pressures and maximum flows across entire simulation. This result set is named Fire Flow Summary.     

4. Results for each individual step or a summary cane be retrieved from Results Browser.

Domestic , or any other demand which is not related to firefighting, will be set to the maximum value during this analysis. This is a realistic scenario, as a fire can happen at any time, and is usually explicitly required by relevant regulations. For example, below is a passage taken from the South African guidelines:

"The minimum residual head should be obtained with the hydrant discharging at the minimum hydrant flow rate, assuming the reticulation is operating under a condition of instantaneous peak domestic demand at the time."