Nancy T. Zacharek, O'Brien & Gere Engineers, Inc.
remain competitive in today's engineering marketplace demands
taking advantage of sophisticated computer technology.
are using, for example, a computer software engineering tool
at O'Brien & Gere Engineers, Inc. to help us better design water
and wastewater systems. This, in turn, is helping our engineering
firm remain competitive by reducing design time and improving
in Syracuse, NY, O'Brien & Gere has been using Design Flow Solutions'
DesigNet software since 1999. The software tool, developed by
ABZ, Inc. of Northern Virginia, assist engineers with the design
of network systems handling liquids and gases that flow through
pipes and process lines.
computer program contains complete hydraulic analysis of complex
piping systems that include up to 9,000 branches and 1,000 tees.
Network branches can consist of any combination of pipe, fittings
and valves, with virtually no limit on the number or type of
also includes a utilities package used for creating, modifying
and managing data files generated by the core program. It provides
users the ability to manipulate data files for fluid properties,
pipe specifications, material specifications, component information,
pumps and unit conversions. Using these utilities, our engineers
can customize the DesigNet program data to include information
that is most useful to them.
company purchased a muti-user license for the software so that
several employees can access it simultaneously. This software
is compatible with our operating systems -- Windows 95, Windows
98 and Windows 200.
to purchasing this software, our engineers performed calculations
either by using alternate software systems or by hand. I preferred
using hand calculations.
which method our engineers choose to use, the same preparations
are necessary. Gathering project-specific information requires
performing hydraulic calculations -- such as piping layout plans,
identifying fluid properties, site conditions, flow-rate ranges
and materials of construction.
preparatory work has been completed, hand calculations require
gathering information from engineering tables or manufacturers'
cut sheets to determine individual looses through each piping
component. This task can be very time-consuming.
of the advantages of DesigNet is that it contains a library of
this information within the software program. In other words,
it does the information gathering for you. As a result, hydraulic
calculations are performed more quickly and more efficiently with
less chance of human error.
The library contains fluid properties for over 50 common liquids
and gases. User-specified fluid properties also can be added
easily. The software allows us to individualize the program
to the specific water/wastewater stream we are working on --
right down to fluid properties, such as temperature, pressure,
specific gravity, density and viscosity.
Another challenge our engineers routinely have to meet is dealing
with changes made in system designs. Changes inevitably occur
as designs progress -- such as pipe sizes and flow rates, and
even switching to different type valves and pumps. These changes
often can affect our entire calculations.
When done by hand, these recalculations were extremely time
consuming. But with DesigNet these changes are made easily by
imputed them into the computer and the software automatically
does the recalculations in a fraction of the time it previously
took us. For example, it changes flowrates with the stroke of
While solving problems is important, it also is important to
see the results. Another advantage our engineers obtain from
this software is flexibility in preparing reports. Output from
the program can be presented using a variety of standard reports
or creating customized reports.
These reports are an excellent way to document calculations
and provide a neat and concise output to our clients. Equations,
summaries or intricate tables detailing every system component
can be made with this software.
Graphic displays also can be made showing valuable information
throughout each step of the network, such as friction losses,
pressure, flowrates, velocity, pipe diameter, etc.
All these factors certainly enhance our design capabilities
and provide us with an excellent hydraulics modeling software
program that helps us remain competitive by reducing design
time and improving engineering accuracy.
Industrial Wastewater Application
This software is especially useful in water/wastewater applications
-- a market we specialize in. We have been heavily involved
in designing such systems, especially for New York communities
and industries, since our founding in 1945.
We recently were involved with the design and construction
of a new industrial wastewater transfer system that was developed
with the use of the DesigNet software.
A portion of our task was to size pumps, piping, equipment
and instruments associated with the system, and estimate system
line losses for this particular application. The computer model
generated with DesigNet represents the industrial wastewater
(a water-like fluid) that was to be pumped via three new end-suction
centrifugal pumps from a 12,000-gallon storage tank to any of
The model was set up in two portions -- the suction side of
the pumps and the discharge side. This arrangement made it easy
to determine pumping capacity required by simply subtracting
the pressures across the networks where the pumps would be.
The model even estimates required horsepower of the transfer
pumps. System output is used to develop a system curve to aid
in selecting the right pump for the conditions.
The modeling was extremely helpful in establishing pumping
capacities for the maximum flow condition, and could easily
be manipulated to determine performance for the average and
minimum flow conditions as well.
This saved time by eliminating recalculation iterations by
hand for different flowrates and site conditions -- such as
pumping from empty tank versus full tank, or pumping to a combination
of destinations. It also was very helpful in estimating inlet
pressures for a multitude of flow control valves associated
with this system, so that these valves could be sized properly
for each flow condition.
In addition, pressure gauges were sized using model output
to estimate the correct scale of gauge. Since the model provides
velocity information, it also is a quick and convenient method
for properly sizing pipe.
The DesigNet program, which is very user-friendly, has an extensive
system Help menu and technical support by phone. We have always
found the ABZ support personnel to be very responsive and helpful,
as well as technically proficient.
If additional help is required for a particular network file,
the software program contains an inherent command to download
the file into a debug file, which can then be sent to ABZ via
Program Help files also contain examples of typical problems,
which serve as a good starting tutorial for new users. All these
features are found right within the software, even the technical
help telephone number is on-line for convenience.
Through the use of the DesigNet software, we have been able
to streamline our ability to readily generate baseline hydraulic
calculations, which has made our project teams more efficient.
Our efficiencies on specific projects are essential in maintaining
our competitive edge in the marketplace and controlling costs
on active projects. While it is difficult to link specific monetary
savings to the use of this software, we are confident that our
investment in the ABZ software has more than paid for itself
on the projects already performed.
About The Author
Nancy Zacharek is a project engineer at O'Brien & Gere
Engineers, Inc. -- which employees over 800 professionals in
offices around the United States and in Puerto Rico, Mexico,
Canada and the United Kingdom. The company provides start-to-finish
engineering, construction, analytical, specialty manufacturing,
operations and property development services to industry, municipalities
and government agencies. To compliment its core competencies,
it offers site development and civil engineering, environmental
compliance and remediation, facilities infrastructure, and project
For more information about O'Brien & Gere call