Applies To Product(s): Bentley WaterGEMS Version(s): 08.11.XX.XX Environment: N\A Area: Layout and Data Input Subarea: N\A Original Author: Nancy Mahmoud, Bentley Technical Support Group Problem How do I develop a pump curve if the only known information is the required flow that the pump should supply? Area: Modeling, Problem ID#: 46730 Solution To estimate the head the pump would need to add, add two junctions to the drawing, one before and one after where that pump will be, without connecting them (see screenshot). Then add the required flow on the first junction as positive demand (J-2), and add the same flow as negative demand (inflow) on the other junction (J-1). The head that a pump would need to add is the difference in hydraulic grade between those two nodes, after running the model. Then add a pump element in place of those two junctions (J-1 and J2), then add a one point design pump curve (with the head estimated from above steps). Run the model, then generate a System head curve (by right-clicking on the pump) to size the pump based on it.
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Wiki Page: Estimating a pump curve for a model
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Forum Post: RE: Darwin Pump Scheduler: Varying Pump Schedule
The pumps are not refilling anytanks downstream. They are set higher at daytime due to higher flow and head loss in the system. We are not yet keen on installing pressure reducing valves downstream as the network is relatively new, and low on NRW. It would be great if you could add the feature in future releases. Thanks!
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Forum Post: RE: Reading Transient Results Viewer From WO.NET
Hi Jessica, A quick suggestion would be to build the code, copy the contents of the output folder to your HAMMER installation folder, then run the exe from there. Consider making a backup copy of the installation folder first. If this does not help, we may need to see your source code.
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Forum Post: RE: Running the Hammer Engine from WO.NET
Hi Jessica, Try my suggestion from your other thread: communities.bentley.com/.../300182.aspx
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Wiki Page: What happens when a tank becomes empty or full?
Applies To Product(s): Bentley WaterGEMS, Bentley WaterCAD, Bentley HAMMER Version(s): 08.11.XX.XX Environment: N/A Area: Modeling Subarea: Original Author: Mark Pachlhofer, Bentley Technical Support Group Problem Description What happens when a tank becomes empty or full? Solution When the water level in the tank reaches the minimum or the maximum (as specified in the properties), a built-in altitude valve will close the adjacent pipe. An empty tank will close the downstream pipe, since it cannot drain any more and a full tank will close the upstream pipe, since it can't fill any more. Once the opposite conditions occur in the system, the pipe(s) will open back up. This can present a problem in some systems, because for example, as soon as the pipe closes for an empty tank, it may instantly be able to fill again from another pipe, triggering the pipe to reopen. As soon as the pipe reopens, it drains to empty, closing the pipe again. This can cause excessive intermediate timesteps and rapid oscillations in the system. So, it is suggested that you configure your controls (typically pump controls) such that the tanks never become full or empty. (Example: If your tank fills at an elevation of 90 ft. you might want to set your pump to shut down at 89.9 ft or if your tank empties at a level of 80 ft. you might set your pump control to shut down at 80.5 ft.) Controls for this might look like this: IF tank T-1 Elevation = 89.9 ft. THEN pump P-1 STATUS = OFF then you would have another control for turning the pump back on IF tank T-1 Elevation = 80.5 ft. THEN pump P-1 STATUS = ON
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Forum Post: RE: design using CivilStorm
thanks for you Jesse and Sushma, but Jesse mentioned that I can use peak flow of SCS unit hydrograph in rational method. the question is how to make this applicable for automated design. or how can I use additional carryover flow in civilstorm for design,i mean where I can enter this value of carryover to represent Peak flow? or the alternative is to design manually each conduit using values of carryover additional flow? thanks Again Rasha Yehia
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Forum Post: RE: Model Problems!
TLFOSTER56, So meaning, these lift stations cannot be operated together at the same time? What are the other reasons behind this situation? Why do the model/system behave that way? Thanks & Regards, June
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Forum Post: RE: Notifications on Sewer Cad V8i
TLFOSTER56, Thanks for your response. I can't get why the model will calculate at elevation 1.72, instead of 5.236 since elevation 5.236 is the real or actual elevation of the stop invert? Will you please explain further? I'm sorry, I missed to state that, the system was already existing/working, so I cannot put manhole like what you are proposing. My goal on this model is actually to check the system, if it is working good or there should be modification to be made on the system so that it will work as expected. So, my question was, Is that notification is really a problem? The model is still calculating even having that error, Will I still get reliable results? Thank you very much! I really appreciate your help. Best Regards, June
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Forum Post: Pump Operation/Behavior on Sewer Cad
Dear All, I have attached a Sewer Cad file. My question was, Why the model cant have all positive pressure? I tried to increase the Head of pump but the system is still having negative pressure? What does it mean? How to rectify this? Please Help! Thanks & Regards, June
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Forum Post: RE: Pump Selecting
Sushma I studied Example no.3 in the models. It is a closed system with one pump. Network contains several Junctions with dissimilar Elevations and Demands. The default Pump is Pump-Definition -2. Now this is the question exactly: How did Designer design a sufficient Pump (for example Pump Definition -2) for this network? My question is about how of pump definition when you do not have ONE specified Demand with with ONE specified Elevation for it. Here we have a network which has many Demands with many Elevations. Sim
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Forum Post: RE: Pump Selecting
Jesse Thank you very much. I will focus on this Wiki page. Would you tell me which page or section of the book you referred to it? Sim
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Comment on Why is StormCAD over-designing the conduits during a design run on a system with very shallow slopes?
I am using civilstorm 8.11.2.75 but I did not find this XML file IncludeConduitFlowTravelTimeInDesignOptions.xml BR, Rasha Yehia
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Forum Post: RE: Pump Operation/Behavior on Sewer Cad
An air valve at the high point will eliminate the negative pressure. Water vaporize when the pressure drops below -32 ft.
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Forum Post: RE: design using CivilStorm
Hi Rasha, My suggestion would basically replace the rational method with user defined flows. Meaning, you would not have catchments in the model (so no runoff calculations) but rather enter the desired peak flows directly into the catchbasins (and those peak flows could be based on an external calculation from the SCS method for example). You can then set the calculation model to Design in the calculation options and it will size the pipes and inlets as it normally would, except it would be using the user-defined flows that you enter instead of flows calculated from the catchments using the rational method. When you have the active numerical solver set to GVF Rational, you'll see the additional carryover flow field in the catchbasin properties:
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Forum Post: RE: Pump Operation/Behavior on Sewer Cad
Sir Tom, I tried to put air valve but it doesnt remove the negative (-) pressure.? Is there any settings needed for the air valve? Regards, June
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Forum Post: RE: Pump Operation/Behavior on Sewer Cad
Make sure "treat as junction" is set to "false". Check the below technote on modeling air valves at high points: communities.bentley.com/.../2644.modeling-force-mains-with-air-valves-tn.aspx
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Forum Post: POND Pack 2 (Dos Version)
We have the PondPack2 (Dos) that runs on Windows 7 (32 Bit). I just got the user a new PC. This machine is Windows 7, but 64 Bit. I can't seem to get the Pond Pack software to function as it should.
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Forum Post: RE: Pump Selecting
Simbaa, You may also want to have a look at this wiki entry which explains how you can estimate the desired head for your pump given you know the flow rate you want. communities.bentley.com/.../16879.estimating-a-pump-curve-for-a-model.aspx Regards, Mark
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Forum Post: RE: POND Pack 2 (Dos Version)
Hello, PondPack 2 for DOS is a very old program and will not work on a 64-bit operating system. You will need to install this on a virtual machine, such as XP Mode, which is offered by Microsoft. Regards, Scott Kampa Bentley Technical Support
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Forum Post: RE: POND Pack 2 (Dos Version)
You might also look into trying something like DosBox for DOS emulation. I'd encourage you to consider upgrading to the latest version we have to offer. As you can imagine, usability and functionality has been greatly improved since the DOS days: www.bentley.com/.../PondPack Some free webinars to show the functionality: Overview of PondPack Pond Design Start to Finish with PondPack
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