• InfoWater Pro

Understanding Fireflow Analyses

Learn how to set up fireflow constraints and how to run fireflow simulations and analyze hydrant curves.


00:04

InfoWater pro provides comprehensive fire flow modeling capabilities.

00:09

Fire demand requirements for hydrants can be specified

00:12

based on the various types of building structure

00:14

including single and multifamily residential, commercial or industrial.

00:20

Other fire demand characteristics are based on land use

00:23

or defined by the fire marshal or city requirements.

00:27

A well set up fire flow model can be used

00:30

to identify hydraulic vulnerabilities due to proposed operational changes.

00:35

The fire flow modeling process is a batch analysis of either all nodes with a

00:39

fire flow demand assigned or all nodes with

00:41

any domain with a fire flow demand assigned

00:45

the basic fire flow analysis is a two-step process that

00:48

automatically assigns the fire flow demand to each junction or hydrant

00:52

and solves for the residual pressure.

00:54

It then sets the residual pressure to the

00:56

specified value and solves for the resulting flow.

01:01

You can then determine the available pressure at the desired fire

01:03

flow demand and the available flow at the minimum residual pressure.

01:08

You can assign fire flow demands to a selected

01:10

junction node using the model explorer tools drop down.

01:15

Alternatively, you can assign a common fire flow demand to all junction nodes

01:18

in the current network domain by using the group editing functionality.

01:23

Fire flow demands are set based on the units you set in the

01:26

simulation options and will match whatever your

01:29

junction demands and flow units are.

01:32

So for example, if you set your flow units to gallons per minute,

01:35

then you could assign demands such as 1500 G PM for new homes.

01:40

You could assign 1000 GPM for some legacy areas or 500 GPM

01:45

for older areas with smaller pipes.

01:48

Fire flow simulations are set up and run in the run manager.

01:52

On the fire flow tab,

01:54

You can set up a standard fire flow run or a design fire flow run.

01:59

For a standard fire flow run, set the residual pressure (20 psi for example)

02:04

for each hydrant (junction node) in the modeled fire flow set.

02:08

Fill in other settings as needed.

02:10

For example, time and duration, if you want to run an extended duration simulation,

02:16

or you could set a maximum velocity constraint for

02:19

the assigned pipes (connecting pipes or domain pipes).

02:23

You can also click edit fire flow table to open the DB editor where

02:27

you can edit fire flow settings for all junctions selected for the simulation.

02:32

Once the standard fire flow simulation is run,

02:35

you can view results in the report manager.

02:38

Iin the fire flow standard report,

02:40

Two key fields that are often used

02:42

are residual pressure and hydrant available flow.

02:46

If the residual pressure is below the residual pressure set in the run manager,

02:50

this is an indication that the location cannot support the required fire flow assigned.

02:57

The hydrant available flow represents the flow rate which

02:59

creates the specified residual pressure at the junction.

03:04

A design fire flow run allows you to set a minimum pressure so that

03:08

pressures are not substantially reduced elsewhere in

03:10

the system, with or without velocity constraints.

03:14

The generated fire flow design report displays

03:17

the minimum pressures in the critical node searching

03:19

range and returns a design flow to be used as a maximum available fire flow.

03:25

This is to maintain minimum pressures in the distribution system.

03:30

Fireflow analyses where more than one hydrant is opened are simulated

03:33

using the multi fire flow tab of the run manager.

03:37

This is useful for examining fire flow either in

03:39

a steady state or in extended period analysis.

03:44

Also, this option can be used with an E P S simulation in which

03:47

one or more fire demands are evaluated over a period of time.

03:51

Users are then able to see how the available flow

03:54

and residual pressures are affected throughout the time steps.

03:58

The run manager also allows you to set up and run a hydrant curve analysis.

04:03

A fire hydrant rating curve shows the relationship between

04:06

residual pressure and the available flow for any hydrant.

04:10

Hydrant curves are often required by

04:12

fire departments responsible for ensuring that a

04:15

specific hydrant can adequately control a potential

04:18

fire demand and maintain minimum pressure.

04:22

The resulting graph details how the hydrant will operate at any given flow rate.

04:27

Any breaks in the curve are caused by a

04:29

change in operation at the specified flow rate.

Video transcript

00:04

InfoWater pro provides comprehensive fire flow modeling capabilities.

00:09

Fire demand requirements for hydrants can be specified

00:12

based on the various types of building structure

00:14

including single and multifamily residential, commercial or industrial.

00:20

Other fire demand characteristics are based on land use

00:23

or defined by the fire marshal or city requirements.

00:27

A well set up fire flow model can be used

00:30

to identify hydraulic vulnerabilities due to proposed operational changes.

00:35

The fire flow modeling process is a batch analysis of either all nodes with a

00:39

fire flow demand assigned or all nodes with

00:41

any domain with a fire flow demand assigned

00:45

the basic fire flow analysis is a two-step process that

00:48

automatically assigns the fire flow demand to each junction or hydrant

00:52

and solves for the residual pressure.

00:54

It then sets the residual pressure to the

00:56

specified value and solves for the resulting flow.

01:01

You can then determine the available pressure at the desired fire

01:03

flow demand and the available flow at the minimum residual pressure.

01:08

You can assign fire flow demands to a selected

01:10

junction node using the model explorer tools drop down.

01:15

Alternatively, you can assign a common fire flow demand to all junction nodes

01:18

in the current network domain by using the group editing functionality.

01:23

Fire flow demands are set based on the units you set in the

01:26

simulation options and will match whatever your

01:29

junction demands and flow units are.

01:32

So for example, if you set your flow units to gallons per minute,

01:35

then you could assign demands such as 1500 G PM for new homes.

01:40

You could assign 1000 GPM for some legacy areas or 500 GPM

01:45

for older areas with smaller pipes.

01:48

Fire flow simulations are set up and run in the run manager.

01:52

On the fire flow tab,

01:54

You can set up a standard fire flow run or a design fire flow run.

01:59

For a standard fire flow run, set the residual pressure (20 psi for example)

02:04

for each hydrant (junction node) in the modeled fire flow set.

02:08

Fill in other settings as needed.

02:10

For example, time and duration, if you want to run an extended duration simulation,

02:16

or you could set a maximum velocity constraint for

02:19

the assigned pipes (connecting pipes or domain pipes).

02:23

You can also click edit fire flow table to open the DB editor where

02:27

you can edit fire flow settings for all junctions selected for the simulation.

02:32

Once the standard fire flow simulation is run,

02:35

you can view results in the report manager.

02:38

Iin the fire flow standard report,

02:40

Two key fields that are often used

02:42

are residual pressure and hydrant available flow.

02:46

If the residual pressure is below the residual pressure set in the run manager,

02:50

this is an indication that the location cannot support the required fire flow assigned.

02:57

The hydrant available flow represents the flow rate which

02:59

creates the specified residual pressure at the junction.

03:04

A design fire flow run allows you to set a minimum pressure so that

03:08

pressures are not substantially reduced elsewhere in

03:10

the system, with or without velocity constraints.

03:14

The generated fire flow design report displays

03:17

the minimum pressures in the critical node searching

03:19

range and returns a design flow to be used as a maximum available fire flow.

03:25

This is to maintain minimum pressures in the distribution system.

03:30

Fireflow analyses where more than one hydrant is opened are simulated

03:33

using the multi fire flow tab of the run manager.

03:37

This is useful for examining fire flow either in

03:39

a steady state or in extended period analysis.

03:44

Also, this option can be used with an E P S simulation in which

03:47

one or more fire demands are evaluated over a period of time.

03:51

Users are then able to see how the available flow

03:54

and residual pressures are affected throughout the time steps.

03:58

The run manager also allows you to set up and run a hydrant curve analysis.

04:03

A fire hydrant rating curve shows the relationship between

04:06

residual pressure and the available flow for any hydrant.

04:10

Hydrant curves are often required by

04:12

fire departments responsible for ensuring that a

04:15

specific hydrant can adequately control a potential

04:18

fire demand and maintain minimum pressure.

04:22

The resulting graph details how the hydrant will operate at any given flow rate.

04:27

Any breaks in the curve are caused by a

04:29

change in operation at the specified flow rate.

Step-by-step:

InfoWater Pro provides comprehensive fireflow modeling capabilities to identify hydraulic vulnerabilities due to proposed operational changes. Fire demand requirements for hydrants can be specified based on:

  • various types of building structures
  • land use
  • fire marshal or city requirements

The fireflow modeling process in InfoWater Pro is a batch analysis of:

  • all nodes with a fireflow demand assigned
    OR
  • all nodes within a domain with a fireflow demand assigned

The basic fireflow analysis is a two-step process that automatically assigns the fireflow demand to each junction (or hydrant) and solves for the residual pressure. It then sets the residual pressure to the specified value and solves for the resulting flow. Users can then determine the available pressure at the desired fireflow demand and the available flow at the minimum residual pressure.

Fireflow demands are assigned to a selected junction node using the Model Explorer Tools drop-down, or a common fireflow demand can be assigned to all junction nodes in the current network domain by using Group Editing.

Setting the fireflow demands individually or as a group editing process.

Fireflow demands are set based on the units you set in the Simulation Options and will match whatever your junction demands and flow units are. So, for example, if you set your flow units to gallons per minute, then you could assign demands such as 1500 gpm for new homes. You could assign 1000 gpm for some legacy areas, or 500 gpm for older areas with smaller pipes.

Fireflow simulations are set up and run in the Run Manager, on the Fireflow tab:

  • Standard Fireflow Run
  • Design Fireflow Run

Standard Fireflow Run example:

  • Residual Pressure (20 psi, for example), for each hydrant (junction node) in the modeled fireflow set
  • Time
  • Duration
  • Maximum Velocity constraint for the assigned pipes (connecting pipes or domain pipes)

TIP: Click Edit Fireflow Table to open the DB Editor, where you can edit fireflow settings for all junctions selected for the simulation.

In the Report Manager, Fireflow Standard Report, there are 2 key fields:

  1. Residual Pressure: if below the Residual Pressure set in the Run Manager, this is an indication that the location cannot support the required fireflow assigned.
  2. Hydrant Available Flow: represents the flow rate which creates the specified residual pressure at the junction.
    The Fireflow settings in the Run Manager, with the Report Manager showing the results in a table format.

A Design Fireflow Run example:

  • set a Minimum Pressure so that pressures are not substantially reduced elsewhere in the system
  • with or without velocity constraints

In the Report Manager, the Fireflow Design Report displays:

  • the minimum pressures in the critical node searching range
  • returns a design flow to be used as a maximum available fireflow
  • maintains minimum pressures in the distribution system
    The Design Fireflow settings in the Run Manager, with the corresponding Fireflow Demand table in the DB Editor.

Multi-Fireflow: Fireflow analyses where more than one hydrant is opened are simulated in the Run Manager.

  • useful for examining fireflow either in a steady state or an extended period analysis
  • can be used with an EPS simulation in which one or more fire demands are evaluated over a period of time
    The Multi-Fireflow settings in the Run Manager, with the corresponding results in the Report Manager.

Hydrant Curve analysis: A fire hydrant rating curve that shows the relationship between residual pressure and the available flow for any hydrant:

  • often required by fire departments responsible for ensuring that a specific hydrant can adequately control a potential fire demand and maintain minimum pressure
  • resulting graph details how the hydrant will operate at any given flow rate
  • any breaks in the curve are caused by a change in operation at the specified flow rate
    The Hydrant Curve settings in the Run Manager, with the corresponding graph in the Report Manager.
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