The water reticulation project can now be exported to EPA Net format. However, several conditions must be met for the results to match:
The Fire Flow Supply Level should be calculated using the Highest Supply Level (HSL). When exporting to EPA Net, the node elevation data in EPA Net will be based on this setting, whether Ground Level (GL) or HSL from MiTS. Take note that peak and average flow used HSL data for their calculation, so if the Fire Flow Supply Level is GL, then the residual pressure might differ a bit between MiTS and EPA Net for nodes with tank water level, since HSL = GL + Tank water level. You might refer to this blog post for more information regarding MiTS calculation in water reticulation.
Options > Project Settings > Water Ret > Design > Fire Flow > Fire Flow Supply Level == GL/HSL
Compared with MiTS, EPA Net did not have the Sluice Valve and Non-return Valve, so make sure the valve used in MiTS did not contain this type of valve if you want to compare both software results.
Verify that both software have similar default values for analysis; Flow Units, Headloss Formula
Checking Default Values for Water Reticulation and EPA Net#
How to check/adjust the value used in each software? You may refer to the following table.
Default Setting
Water Reticulation
EPA Net
Flow Unit = LPS
Options > Project Settings > Water Ret > Input > Water Demand Units
Ribbon Tab > Project > Analysis Options… > Flow Units
Headloss Formula = Hazen-Williams/Darcy-Weisbach
Options > Project Settings > Water Ret > Design > Headloss Formula
Ribbon Tab > Project > Analysis Options… > Headloss Formula
This example project file has both MiTS and EPA Net’s projects. The project file contains a pump curve, pressure breaking valve (PBV) and tank water level.
The terms used in MiTS and EPA Net are different. Below are the terms used in both software.
The comparison between EPA Net and MiTS shows similarity in the residual pressure of the node while the comparison of headloss in a few pipes has a difference of 0.001 m/km. The list of the pipes with this difference is shown in the table below.
HWC
Pipe No
Headloss (m/km)
EPA Net
MiTS
Average Flow
16
0.027
0.026
16
0.017
0.018
Peak Flow
17
0.027
0.026
DWC
Average Flow
4
1.944
1.943
15
0.087
0.086
While the data between EPA Net and MiTS is similar, when the term of comparison is between the headloss formula (Hazen-Williams vs Darcy-Weisbach), the difference of value can be seen significantly for both node’s residual pressure and pipe’s headloss. This difference in value is due to the different formulas used for the calculation of the headloss;
Hazen-Williams headloss,
HL =
10.67LQ1.852C1.852d4.871
Darcy-Weisbach headloss,
HL =
fLv22dg
Here is a simple project file created in EPA Net 2.2 showing the different results when using different headloss formulas, HWC vs DWC
Here is the EPA Net 2.2 Installer for you to try on your own
In conclusion, the results obtained from both software are similar. Though there are a few pipes with a difference of 0.001 m/km headloss, it can be said that MiTS’s Water Reticulation module and EPA Net produce a similar result.
This provides us with confidence that our Water Reticulation module’s analysis is accurate.
