Forum Post: RE: Negative Demand
Sim, It looks to me like all nodes have a HGL of 10m. Based on that, would you conclude that the "HGL of a Junction that has a positive Demand is equal to HGL of lowest Tank or Reservoir of the...
View ArticleForum Post: RE: Pump Selecting
Inserting a 'dummy' reservoir is likely to give incorrect results. Better to use 'pressure dependent demands' and then create a system head curve at the pump that you are trying to design. See the...
View ArticleForum Post: RE: Help With setting up a VSP or VFD with 4 pumps.
It could be that you have a conflict with another control statement. To make sure that this control statement will be used, set it to a higher priority than any other statement for this pump. (The...
View ArticleForum Post: RE: Help With setting up a VSP or VFD with 4 pumps.
Also make sure the controls are included in the control set you're using in the scenario in question (if you are using one). If this doesn't help, you can zip and attach the model files here, or...
View ArticleForum Post: what is the difference between ''pressure'' and ''pressure head''
Hello, what is the difference between ''pressure'' and ''pressure head'', according WaterCAD Best regards
View ArticleForum Post: RE: what is the difference between ''pressure'' and ''pressure...
Vanfa, The pressure head is the hydraulic grade - the physical elevation of the junction and the pressure is the same, but also takes into account the specific gravity of water which is 0.998....
View ArticleForum Post: RE: what is the difference between ''pressure'' and ''pressure...
I'll add that the specific gravity can be changed in the calculation options (View Calculation Options) depending on the exact fluid and temperature.
View ArticleForum Post: RE: what is the difference between ''pressure'' and ''pressure...
Even more general Pressure head refers to the energy from pressure expressed in length units (m, ft) and is calculated as the difference between the HGL and elevation of the point at which it is...
View ArticleForum Post: Fire flow in dedicated fire main
I am new to WaterCAD. A hydrant test was performed 25' from the entrance to a proposed community. This community will have a dedicated fire main as well as a water main for daily demands. The fire...
View ArticleWiki Page: What is the difference between pressure head and pressure in...
Applies To Product(s): Bentley WaterCAD, Bentley WaterGEMS, Bentley HAMMER Version(s): 08.11.XX.XX Environment: N\A Area: Output and Reporting Subarea: N\A Original Author: Mark Pachlhofer, Bentley...
View ArticleForum Post: StormCAD Model Results and Maximum Network Traversals
Hi, I have a StormCAD model. The model was working fine when I was using StormCAD Series 2. I had to go back and revise the model, and when I changed pipe sizes, the model suddenly would not converge....
View ArticleForum Post: RE: Pump Selecting
Dear Mall Thank you very much for your good responses. I read below Wikis carefully: communities.bentley.com/.../15371.system-head-curves-with-no-downstream-storage-solution-500000056093.aspx...
View ArticleForum Post: RE: Negative Demand
Dear Mall Please have a look at attached model. You are right. After running the model there will no any eproblem occur and every thing go well. A question remains is that if ‘assigning negative...
View ArticleForum Post: RE: StormCAD Model Results and Maximum Network Traversals
Hello, The reason is because there is an enhancement in SELECTseries 3 (and greater) which is only invoked when setting the Maximum Network Traversals to a value of 30 or greater. I've created the...
View ArticleForum Post: RE: Pump Selecting
Once you have the system head curve (which is independent of the pump curve), you can overlay some candidate pump curves to select the one that intersects the system head curve near optimal...
View ArticleForum Post: RE: Negative Demand
With a pump, it will shift on its curve based on the system conditions. When using a negative demand on a junction, it will always inject that flow rate regardless of the system conditions. A negative...
View ArticleForum Post: Convergence NOT Achieved
Hi, I have a StormCAD model that was created using V8i Version 2. There are four outfalls in the model. Each storm drain system leading to the outfall is mostly surcharged because the starting outfall...
View ArticleForum Post: RE: Convergence NOT Achieved
Hello, Please see my post below that links to an article that explains what is going on behind the scenes when you set the max traversals above 30 and why this change was implemented:...
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