There are three components to the InfoWater Pro Fireflow Run Results, Standard Fireflow Run, Design Fireflow Run, and Asset Reporting. Based on which analysis is evaluated different reports will be generated. It is important to understand how each of the reports display output results and how these results may vary based on the constraints specified.
Fireflow Standard Report
The first report is a standard fireflow simulation. This report includes static demand, static pressure, static head, fireflow demand, residual pressure, hydrant available flow, and hydrant pressure at available flow. Two additional columns are included when you choose Max. Velocity from Run Manager dialog box.
The fireflow report contains the same information, regardless if Design Fireflow is checked or not.
ID - Hydrant (Junction node) Identifier.
Static Demand - The nodal demand at the fireflow simulation timestep. This value corresponds to the baseline demand at the specified timestep.
Static Pressure - The nodal calculated pressure for the static demand at the fireflow simulation timestep.
Static Head - Node hydraulic grade at the current simulation time step, ft (m).
Fire Flow Demand - The user-specified fireflow demand at the current node when the hydrant is flowing.
Residual Pressure - The residual pressure at the current junction which includes both the fireflow demand plus the static demand. This pressure value assumes that only the current hydrant (node) is subjected to the assigned fire demand and that no other fire demands are considered in generating this value.
Hydrant Available Flow - The maximum flow that is available while maintaining the user-specified minimum residual pressure at the current node, assuming that only this hydrant (node) is flowing.
Hydrant Pressure at Available Flow - Residual pressure calculated for the available flow at the current hydrant (node). This value should equal the residual pressure specified by the user.
Note: These two additional columns appear when you choose Max. Velocity in your Report Manager settings.
Critical Pipe ID at Available Flow (optional)- The pipe with the highest velocity within our Pipe Search Range assigned by the user under the fireflow tab of the Run Manager. It will be blank if the velocities of the selected pipe are less than the maximum velocity assigned by user.
Critical Pipe Velocity at Available Flow (optional) - The velocity of the critical Pipe after satisfying the maximum velocity constrain. It will be blank if the velocities of the selected pipe are less than the maximum velocity assigned by user.
Fireflow Design Report
InfoWater Pro will generate a fireflow design report that determines the minimum pressures in the critical node searching range and returns a Design Flow to be used as a maximum available fireflow in order to maintain minimum pressures in the distribution system.
The velocity constraint is only considered in the available flow and design flow calculation if the maximum velocity option is selected.
ID - Hydrant (Junction node) identifier.
Capacity Assessment - Provides "PASS" or "FAIL" based on a comparison of the Hydrant Design Flow and the Total Demand. Capacity failure is assigned when the Hydrant Design Flow less than the requested Total Demand.
Total Demand - The total nodal demand at the fireflow simulation timestep. This value corresponds to the sum of the baseline demand (Static Demand) and the fireflow demand (Fireflow Demand) for the selected timestep.
Hydrant Available Flow - The maximum flow that is available while maintaining the user-specified minimum residual pressure at the current node, assuming that only this hydrant (node) is flowing.
Critical Node ID for Design Run - The node within the Critical Node Searching Range with the lowest pressure when the current nodal junction is loaded with the total demand.
Critical Node Pressure at Available Flow: The calculated pressure at the critical node when the full available hydrant flow is applied to the hydrant node.
Critical Node Pressure at Fire Demand: The calculated pressure at the critical node when Total Demand is applied at the hydrant. Recall Total Demand = Static Demand + Fireflow Demand.
Critical Pressure for Design Run: The required minimum design pressure at all search nodes which is input by the user. This value can be customized for each junction using the Fireflow Demand table in the DB Editor.
Hydrant Design Flow - The maximum flow available at the current hydrant (node) such that the pressure anywhere within the critical node searching range (Fire Nodes, Entire Network, or Domain) does not drop below the minimum design pressure specified. Based on the critical nodes identified (junction node with minimum pressure in the critical node searching range), InfoWater Pro determines the design flow as the minimum of the adjusted flows for each junction node needed to maintain the minimum design pressure in the entire critical node searching range. Ultimately, the Design Flow as it is the least flow value of all considered residual pressures and velocity constraints. This is the value that an engineer would provide to a local fire department by saying this is the maximum (theoretical) flow possible at the subject junction in order to maintain 20 psi at all times in the distribution system.
Hydrant Pressure at Design Flow - The current flow available at the current node such that the hydrant pressure does not drop below the minimum design pressure specified.
Note: These two additional columns appear when you choose Max. Velocity in your Run Manager dialog box.
Critical Pipe ID for Design Run (optional) - If Max. Velocity Constraint is checked, this column will be created to show the pipe ID with the highest velocity within our Pipe Search Range assigned by the user. It will be blank if the velocities of the selected pipe are less than the maximum velocity assigned by user.
Critical Pipe Velocity at Design Flow (optional) - If Max. Velocity Constraint is checked, InfoWater Pro calculates the maximum flow available at the hydrant while maintaining the user-specified residual pressure and the maximum velocity constraint. This value presents the velocity of the critical Pipe after satisfying the maximum velocity constrain. It will be blank if the velocities of the selected pipe are less than the maximum velocity assigned by user.
Explanation on Fireflow Reports
Fireflows are an integral part of the Hydraulic modeling process and provide a means to calibrate your model. Use the InfoWater Pro Fireflow module to analyze existing hydrants or provide recommendations for future build-outs.
In InfoWater Pro, there are four constraints that are applied while conducting fireflows.
Constraint 1- The Fireflow demand imposed on each hydrant.
Constraint 2 - The Residual Pressure that imposed on the Hydrant through the InfoWater Pro Run Manager dialog box. This is the minimum pressure allowed at the hydrant.
Constraint 3 - The Minimum Design Pressure that is imposed on the junctions that may be affected when the Hydrant supplies water during a fireflow simulation. Include these junctions by assigning them to your Critical Node Searching Range.
Constraint 4 (optional) - The Maximum Velocity Constraint can be additionally assigned on the top of Residual Pressure Constraint. This will affect the fireflow analysis and the fireflow design.
Asset Impact Reports
In addition to the above reports that focus on each hydrant included in analysis, InfoWater Pro offers reports that summarize the impact of each asset in the system, as experienced across all simulated hydrant fire flow conditions.
These reports are only available when Asset Impact Reporting is turned on.
Fireflow Pipe Impact Report
This report is used to identify capacity bottlenecks in the system, namely when certain pipes consistently experience high velocities and headloss. When fire flow requirements are a driver for pipe size, this report can help prioritize which pipes to consider upsizing.
ID - Pipe ID.
Maximum Velocity - The maximum velocity experienced by the pipe for all fireflow cases.
Maximum Flow - The maximum flow experienced by the pipe for all fireflow cases.
Maximum Unit Headloss - The maximum unit headloss experienced by the pipe for all fireflow cases.
Maximum Velocity Increase - The increase in velocity between the critical hydrant flow condition and the base flow conditions when no fire flows are occurring.
Critical Hydrant ID - The Hydrant that causes the maximum velocity in the pipe when flowing at the selected fireflow condition.
Velocity Warning Count - The total count of simulated hydrant test cases where the pipe velocity exceeded the warning threshold provided in the Run Manager.
Velocity Violation Sum - The sum of all velocity violations across all fireflow test cases where the velocity threshold was exceeded. Namely, this is the Sum of the differences between the pipe velocity and the warning threshold, considering only positive cases.
Flow Violation Sum - The sum of all flowrate violations across all fireflow test cases. A flow violation is approximated based on the velocity threshold and the diameter of the pipe. The value reports the sum of differences between the pipe flow and the flow threshold for all warning cases.
Fireflow Junction Impact Report
This report is used to identify critical pressure nodes throughout the system. The results include both the lowest pressure experienced, as well as information about the frequency of pressure warnings across all hydrant fire flow cases.
ID - Junction ID.
Minimum Pressure - The minimum pressure experienced by the junction for all fireflow cases.
Maximum Pressure Drop - The decrease in pressure between the critical hydrant flow condition and the base flow conditions when no fire flows are occurring.
Demand At Minimum Pressure - The base demand at the junction.
Critical Hydrant ID - The Hydrant that causes the minimum pressure in the junction.
Pressure Warning Count - The total count of simulated hydrant test cases where the junction pressure fell below the warning threshold provided in the Run Manager.
Pressure Violation Sum - The sum of all pressure violations across all fireflow test cases. Namely, this is the Sum of the differences between the junction pressure and the warning threshold, considering only warning cases where the pressure fell below the threshold.