Applies To Product(s): Bentley WaterGEMS, Bentley SewerGEMS, Bentley CivilStorm, Bentley SewerCAD, Bentley HAMMER, Bentley WaterCAD Version(s): 08.11.XX.XX Area: Output and Reporting Original Author: Mark Pachlhofer, Bentley Technical Support Group Problem When I look at the controls manager I can't see the bottom of the dialog box no matter how big make the window? How can I fix this? Area: General, Problem ID#: 86374 Solution The likely problem is that your font size is set to something larger than the normal setting. The normal settings is 96 DPI. There are various places to change this depending on which operating system you have. If you talk to your IT person they should be able to help you check or change these settings to fix the problem.

Applies To Product(s): Bentley WaterGEMS, Bentley WaterCAD, Bentley SewerGEMS, Bentley SewerCAD, Bentley StormCAD, Bentley CivilStorm, Bentley HAMMER Version(s): 08.11.xx.xx, 10.XX.XX.XX Area: Output and Reporting Original Author: Scott Kampa, Bentley Technical Support Group How To: How do you add color coding to an element? Steps to Accomplish You can add color coding through Element Symbology. The steps to do this can be found below. Note : It is not possible to have more than one color-based (or size-only based) color coding entry active at the same time. The first time in the list will be the one that is displayed in that case. It is possible to use the Shift Up or Shift Down buttons in element symbology to move the color coding or annotation items in the list to that the more important one is active if more than one item is checked. However, it is possible for a color-based and a size-based color coding entry to be active at the some time. So if you wanted to have color-based entry based on flow and a size-based entry based on pipe diameter, you could have these active at the same time. This is sometimes docked to the left of the drawing, and can also be obtained by going to View > Element Symbology. In Element Symbology, right-click on "Pipe" and choose New > Color Coding. This will open a new dialog that will allow you to set up the color coding. You can then choose the field you want to color code by clicking the dropdown menu for "Field Name": If you only want to color code a certain selection set of items, you can choose that in the Selection Set field. Next you will need to set a range for the diameter. This can be done automatically by clicking the "Calculate Range" button. The program will detect the smallest and largest value for the property. The default number of steps is 5. These values can be manually adjusted. On the left side of the color coding dialog is where you set the colors that will be used. In the upper-left, you can select the dropdown windor for "Options" do define if you want to use Color, Size, or both color and size. If the size option is used, different elements will not only have a different color, but also a different size. To automatically assign a range of colors, click the Initialize button on the left side of the color coding properties dialog. By doing this, the program will assign colors to the property field range you assigned on the right side of the dialog. These colors can be adjusted manually by selecting the cell in the Color column. If you use the Size or Color and Size option, a Size column will be added as well. This can be manually adjusted. To apply the color coding properties to the drawing, click Apply, then Ok. The color coding should be applied. If not, try going to View > Refresh Drawing. Note : If the property field you are color coding by is a calculated results field, you may need to calculate the model before the color coding will appear in the drawing. In addition, not all calculated results fields will be available all calculation types. For instance results that are specific to water age or fire flow will only be available for those types of analyses. Otherwise, the results will be listed as "N/A" and the range will not be available. See Also How do I annotate model elements?

Applies To Product(s): Bentley WaterGEMS, Bentley WaterCAD, Bentley SewerGEMS, Bentley SewerCAD. Version(s): 08.11.XX.XX. Environment: N\A Area: Other Original Author: Nancy Mahmoud, Bentley Technical Support Group Problem How do I create a .kmz file out of my model file? Problem ID#: 46282 Solution Open the WaterGEMS/CAD file in Microstation. 1) Go to Tools > Geographic > Select Coordinate System. If the file has a coordinate system, then skip this step. 2) From the File menu, go to Export > Google Earth. Enter a name for the .kmz file. See Also How do I import a Google earth image so it lines up with my model?

Product(s): Bentley SewerCAD Version(s): 08.11.02.49 Area: Calculations Problem Is it possible to have the automated design feature design a conduit's inverts but not the size? Can I "set" the pipe diameter and have the program design only the inverts? Problem ID#: 61071 Solution Currently (as of 08.11.02.49) it is not possible for the program to automatically design the inverts but not the size. This has been logged as a feature request for future consideration. The typical use case, which the program was designed for, is the design of a proposed system where both the sizes and the inverts are designed. Keeping the sizes the same would indicate that you may be redesigning an existing system using the existing conduits, but possibly burying them at a different depth. This is a bit of an atypical case, hence the need for a workaround. Here's what you can do to workaround this issue: 1) Open your conduit flextable and add the label column along with the diameter column and place them next to each other. 2) Sort your conduit table by ascending labels by right clicking on the label column header and choosing Sort > Sort Ascending. 4) Highlight all the records for the label and diameter columns and hit the CTRL + C to copy them 5) Open a new Excel spreadsheet and paste the information in. 6) In the conduit flextable add the conduit type, conduit class, and size fields if they're not already available. 7) Global edit the conduit type from "User Defined" to "Catalog Conduit". You do this by right clicking on the conduit type column header and choosing global edit. 8) Open the conduit catalog (Components > Conduit Catalog) and add in some conduit shapes and make a few sizes available for design by checking the box labeled "Available for design?". If you want you can just import some from the engineering library by clicking on the drop down arrow next to the book icon and choosing import from library. 9) In the conduit flextable right click on the conduit class field and choose to global edit it. Choose one of the shapes. Now right click on the size field to global edit that then choose one size for all the conduits. 10) Run the software in design mode to update all your inverts. 11) Open your conduit flextable and global edit the conduit type field to "user defined". Make sure all your conduits are still sorted by label in ascending order. 12) Copy the diameter information from the Excel spreadsheet and paste it back to the diameter field in the flextable. See Also Is there any way to only adjust the pipe size without changing the invert?

Applies To Product(s): SewerGEMS, SewerCAD Version(s): 08.11.XX.XX, 10.XX.XX.XX Area: Layout and Data Input Original Author: Jesse Dringoli, Bentley Technical Support Group Overview This Technote describes how the Flow Monitoring Distribution method works and how to use it to import your loads in the LoadBuilder module for either SewerCAD or SewerGEMS. It assumes version V8i is used, but the process may be similar in V8 XM. Background In SewerGEMS and SewerCAD, the LoadBuilder module can be used to import sanitary loads using many different methods. Flow monitoring distribution is a new method in LoadBuilder (as of SewerGEMS 08.09.26.17 and SewerCAD 08.11.00.48) which should be used if your loading data consists of shapefiles representing monitored flows. All of the other Loadbuilder methods work with actual individual metered loads, where the loading data represents flows directly entering customer locations. Monitored flows represent flows that were measured by a meter at a certain location inside the piping of a sewer network. So, the downstream most meter will represent the flows from everything upstream of that point, NOT a single load that entered that specific point. How the Flow Monitoring Distribution Method Works The flow monitoring distribution method assigns loading data from a point load monitoring layer to upstream loading nodes. It automatically identifies all the upstream manholes up to its adjacent next upstream load monitor, works out the sub-total load contribution of the manhole between the load monitors (i.e., the load difference between the monitors), and then equally distributes the effective load to all the contributing manholes. To visually explain what this means, take the following network for example: Note: the green diamonds represent the locations of the meters in a point shapefile. If the meter locations did not fall exactly on top of a manhole, loadbuilder would calculate the nearest node (manhole) and use that. Assume the following monitored flows: Meter #1 - 100gpm Meter #2 - 150gpm Meter #3 - 550gpm This means that the flow through the piping under manhole C was 'monitored' as 100gpm, the flow under manhole F as 150gpm and the flow under manhole I as 550gpm. So, since Meter #3 is the downstream-most meter, we can say that the total load upstream of that point is 550gpm. This means that in the end, the total loads entering the system will add up to 550gpm. So, LoadBuilder must compute what the individual loads for each manhole would be, in order for the above to be true. Starting from upstream: • Total flow at Meter #1 is 100gpm. Since 3 manholes (A, B and C) are upstream, each would need to have 33.33gpm (100 / 3 = 33.3) • Total flow at Meter #2 is 150gpm. Since 3 manholes (D, E and F) are upstream, each would need to have 50.0gpm (150 / 3 = 50.0) • Total flow at Meter #3 is 550gpm, which is 300gpm more than the total of the 2 other meters. So, we know that there is 300gpm (550 - 250 = 300) coming into the system somewhere between it. So, since there are 5 manholes between them, (G, H, I, J and K) each of those manholes would need to have 60.0gpm (300 / 5 = 60.0) How to use this method in LoadBuilder 1. In the LoadBuilder wizard, select Flow Monitoring Distribution under the "Allocation" section. 2. For the "Node Layer", select which elements the loads will be assigned to. Typically this will be "Manhole\All Elements", meaning all the manholes. If you have a selection set of loadable manholes, select "Manhole\ ", where " " is the name of the selection set. - Leave the "Node ID Field" as "ElementID". - For the "Flow Monitoring Layer" , select the shapefile (or point feature class, if using the ArcGIS integrated mode) that contains the flow monitoring meter data. - For the "Usage Field" , select the attribute that contains usage data. The usage field in the source database must contain flow data. Be sure to select the correct unit as well. 3. Click Next and LoadBuilder will compute the total load that will be assigned to the manholes. In our example case, this is 550gpm. If you need to apply a global pattern or multiplier to that total value, you can do so. Note: if you need to change the flow unit in the above window, right click the column header for "Consumption", select "Units and Formatting", choose the appropriate unit and click OK. 4. Click Next and LoadBuilder will compute the load allocations. A summary window will show you each manhole's load. If you need to assign a different pattern to each one, you can do so here. Notice that no load was assigned to manhole L - this is because it is downstream of the downstream-most meter - Loadbuilder has no way of knowing what the metered flow is here, and assumes it is the same as the downstream-most node (550 gpm in this case.) Thus, no additional loads enter the system at that downstream point. 5. Click Next and you will be given several choices as to where the new loads will be imported to. If you would like these new loads to override the loads already present in a particular Sanitary Loading alternative (such as the one associated with the current scenario) then select "Override an Existing Alternative" and select the one you want. If you would like the new loads to be added to the loads already present in a particular Sanitary Loading alternative, select "Append to an Existing Alternative" and select the one you want. If you would like to create a new alternative to store the new loads (and later assign it to a particular scenario), select "New Alternative" and enter a name. In this case, we will select to override: 6. Click Next and LoadBuilder will import the new loads into the desired alternative. You'll be presented with a summary window, where you can view statistics and any problems that may have occured. 7. At this point, you can close LoadBuilder, check or assign your alternative, and view your loads using the Sanitary Load Control Center (located in the Tools menu). See Also Product TechNotes and FAQs Haestad Methods Product Tech Notes And FAQs Hydraulics and Hydrology Forum External Links Bentley homepage Bentley Technical Support KnowledgeBase Bentley LEARN Server

Applies To Product(s): WaterCAD, WaterGEMS, HAMMER Version(s): V8 XM, V8i, CONNECT Edition Area: N/A Original Author: Jesse Dringoli, Bentley Technical Support Group Overview WaterCAD and WaterGEMS have the ability to model multiple minor losses in a single pipe. This technote explains how to do it. Background WaterCAD/GEMS won't calculate the losses automatically if you place pipe bends, etc. You must account for these losses by using minor loss coefficients. In some modeling cases, it might be necessary to represent multiple minor losses in a particular pipe. For example, if there are multiple bends throughout the pipe, plus a gate valve. Adding Minor Losses to WaterCAD/GEMS In the Pipe Properties window, set the Specify Local Minor Loss field to False . This will enable the field for Minor Losses. Click inside the box for the Minor Losses field and you'll see the ellipsis button (...) appear as in the screenshot above. Click the Ellipsis (...) button to bring up the Minor Losses window for that pipe: Click in the Minor Loss Coefficient box to bring up the ellipsis button like in the screenshot above. Click the Ellipsis (...) button; this will bring up the Minor Loss Coefficients window: You'll notice that the Minor Loss Coefficients window is currently empty. Click on the down arrow next to the book and you'll get the following menu: Click the Import from Library option. This will open the Minor Loss Engineering library: Click on the + sign in front of the Minor Loss Libraries entry and then the MinorLossLibrary.xml entry to list all of the minor losses currently in this library. Click on one of the minor loss entries to highlight and select it: With the minor loss entry highlighted, click the Select button and this will add the minor loss to you Minor Loss Coefficients window. If you have multiple minor losses, you will need to repeat steps 4-8 again to add the other minor losses to this same window-in the screenshot below, I have added 2 more minor losses to this window: Click the Close button to close this window. Back on the Minor Losses window, click on the dropdown box in the Minor Loss Coefficient column and you should see all of the minor losses that you had imported into the Minor Loss Coeffiecients window in steps 4-9 (in the case of this example, the 3 minor losses I had added show up): Select the appropriate minor loss for this particular pipe. If there are multiple minor losses, add each minor loss onto a separate line: Set the Quantity field to the appropriate number of occurrences of that minor loss in that pipe. After all of the appropriate minor losses have been selected, click the OK button to close this window. Back on the Pipe Properties window, the Minor Losses field value will update to list the correct number of minor losses that was added (3 items in the case of this example) and the Minor Loss Coefficient (Derived) field should update to the correct composite minor loss value. Adding multiple minor losses to multiple pipes at one time using Modelbuilder 1) You will need to have a spread sheet with 3 columns: a) Label b) Minor Loss Label c) Quantity This is a sample of what your worksheet might look like Minor Losses worksheet for Modelbuilder Note: The minor loss label will be the exact label name that you have listed in the minor loss coefficients manager 2) Create a selection set of pipes that you are going to be adding a collection of minor losses for. 3) Open your flextable based on that selection set . Edit the flextable and add the column titled "Specify Minor Loss Coefficient?" then set it to "False", which is a blank checkbox. 4) Open ModelBuilder (Tools > Modelbuilder) and start a new run. 5) In step one choose the appropriate Excel datasource, which will likely be "Excel 2013 / 2010 / 2007 (12.0)" and click the Next button twice 6) On step 3 make sure your options are set up as shown below and click the Next button twice 7) Set the Table Type to "Pipe, Minor Losses" (blue box) and the Key Field to "Label" (red box). In the field mapping steps below (green box) match the Minor Loss field to the "Minor Loss Coefficients (Label)" and the Quantity field to the "Quantity". Click Next when done. 8) When asked in the last Modelbuilder step if you'd like to build a model choose "Yes" your information will be imported. Double check to make sure the information is correct on a few pipes. See Also Product TechNotes and FAQs Haestad Methods Product Tech Notes And FAQs [[General WaterGEMS V8 FAQ|General WaterGEMS V8 FAQ]] Hydraulics and Hydrology Forum External Links Bentley SELECTservices Bentley LEARN Server

Applies To Product(s): Bentley CivilStorm, Bentley SewerGEMS Version(s): 08.11.XX.XX Environment: N\A Area: Layout and Data Input Subarea: N\A Original Author: Jesse Dringoli, Bentley Technical Support Group Problem When using the SWMM calculation engine (Engine type set to "Explicit"), a high continuity error or generic user notifications are seen and results appear to be unstable. Problem ID#: 51262 Solution There are many things that can cause a high continuity error with the SWMM calculation engine. First, double check all your data input for errors and review the User Notification list. Next, try reducing the " routing time step " in the calculation options. Reduce it gradually until results are better. For example, you may try a routing time step of 30 seconds, 10 seconds, 5 seconds, 2 seconds, down to a minimum of 0.1 seconds for very difficult models. Smaller routing time steps are often needed in models with fast-changing conditions such as pumps that cycle and sensitive control structures (especially weirs) and flow splits. In more recent versions of SewerGEMS and CivilStorm, you can adjust the Max Trials per Time Step and Head Convergence Tolerance calculation options, and view pipe convergence statistics in the output report, just below the mass balance section. Export the file to SWMM by going to File > Export > EPA SWMM. Open the file in the latest version of EPA SWMM, which as of today is version 5.1.0011, then compute the model and troubleshoot the messages in the status window. If you're using pumps in your model, check the on and off elevation range, pump curves and adjacent pressure pipes. With the Explicit solver, better stability is typically achieved when using a virtual pipe on either side of the pump. For example, the pipe between the wetwell and the pump - set "is virtual?" to "true". Also, a particulary small routing step may be needed. Additionally, try using Muti-point as the pump curve type, as this can typically yield better results. Review storm data and to make sure it's entered correctly and there is a label associated with each storm event. Review the labels for your elements and fix any duplicates. To find duplicate labels you can use Network Navigator > Input > Duplicate Labels. See Also Troubleshooting unstable SewerGEMS and CivilStorm results using the Implicit solver

Applies To Product(s): Bentley WaterCAD, Bentley WaterGEMS Version(s): V8 XM, V8i, CONNECT Edition Area: Output and Reporting Original Author: Jesse Dringoli, Bentley Technical Support Group Overview This Technote explains how to interpret and troubleshoot calculated results for an automated fire flow analysis in WaterCAD or WaterGEMS V8 XM or V8i. Before reading this Technote, it is recommended that the user complete the Fire flow Quick start lesson. This is located in the WaterCAD/WaterGEMS help, under Contents > Quick Start Lessons > Automated Fire Flow Analysis. Background Fire Flow analysis is a common tool used in WaterCAD and WaterGEMS to ensure enough protection is provided during fire emergencies. The user is able to enter constraints in order to determine how much fire flow is available at hydrants while adequate system pressure is maintained. Several tools available to aid in understanding fire flow results. With the release of WaterGEMS V8i SELECTseries 6, the SCADAConnect Simulator tool has a new option: Fire response. Fire Response enables you to place a fire demand (or other emergency flows) at a node for a period of time to determine its impact on pressure and flows and possibly test alternative ways of responding to the fire. Here is the technote on that. How Does Automated Fire Flow Work? Fire flows are computed at each node by iteratively assigning demands and computing system pressures. When you execute a fire flow analysis, WaterCAD\GEMS will: Calculate a steady-state simulation for all nodes designated as fire-flow nodes. At each node, it begins by running a Steady-State simulation using only non-fire demands, to ensure that the fire flow constraints (e.g., minimum residual pressure, minimum zone pressure) that have been set can be met without withdrawing any Fire Flow from any of the nodes. Evaluate the Fire Flow Upper Limit and Available Fire Flow at each of the fire-flow nodes. Assuming the fire flow constraints were met in the initial run, the program performs a series of steady-state runs in which flow is applied to each specified fire-flow node and results are evaluated against fire-flow constraints. Note that the fire flow for each individual node is evaluated using a separate analysis (i.e., needed fire flow is not applied simultaneously to all fire-flow nodes). The program performs a series of steady-state analyses in which the Fire Flow Upper Limit discharge is applied to each node in turn. If the fire flow constraints are met for the Fire Flow Upper Limit discharge, the node satisfies the fire flow constraints and no further analysis is required for that node. The program then performs a series of steady-state analyses in which it iteratively assigns lesser demands to nodes that do not meet Fire Flow Upper Limit constraint to determine the Avalable Fire Flow. The Available Fire Flow is the maximum fire flow that each node can supply without violating fire flow constraints. If the Available Fire Flow is greater than or equal to Needed Fire Flow, the node satisfies the fire flow contraints. If Available Fire Flow is less than Needed, it does not. Run a final Steady-State calculation that does not apply Fire Flow demands to any of the junctions. This provides a baseline of calculated results that can then be compared to the Fire Flow conditions, which can be determined by viewing the results presented on the Fire Flow tab of the individual junction editors, or in the Fire Flow Tabular Report. Interpreting the Fire Flow Alternative Configuration for an automated fire flow analysis is done under the Fire Flow alternative. This is found under Analysis > Alternatives > Fire flow. When computing a scenario, the fire flow alternative assigned to that scenario is used. At a minimum, you should specify values for the needed Fire Flow, Fire Flow Upper Limit, Apply Fire Flow By, Residual Pressure Lower Limit, Zone Pressure Lower Limit and Fire flow nodes selection set. Below is an explanation of each of the main fields found in this alternative (when double clicking on it): Note: If the above options need to be configured differently for each junction/hydrant, you can specify "local" fireflow constraints by clicking the "specify local fireflow constraints?" check box next to the junctions/hydrants in the list at the bottom of the fireflow alternative. If this box is not checked, that particular fireflow node will utilize the global constraints entered at the top of the fire flow alternative. Note: it is important to understand that for the minimum zone pressure constraint, the program checks pressures for all other nodes in the model that are assigned to the same zone as the fireflow node in question. The zone is an attribute of the node. Say for example there are two nodes in the fireflow selection set: J-1 and J-2. J-1 is assigned to Zone A and J-2 is assigned to Zone B. Fireflow nodes are checked independently during the analysis, so when J-1 is being computed, the program will check pressures at all other nodes that are also assigned to Zone A and compare against the minimum zone pressure constraint. Then, when the analysis moves on to J-2, it will be checking pressure at all nodes assigned to Zone B. So, the program isn't running a fireflow analysis on a particular zone - it considers pressures at nodes assigned to certain zones, based on the fireflow node it is currently analyzing. Configuring your model to run a fire flow analysis After you've configured your fire flow alternative, the next step is to assign that alternative to the scenario you would like to compute. First, go to Analysis > Calculation Options. If you have an existing calculation option set that you're using in other scenarios, click on it and click the "duplicate" button. If you'd like, you could also click the "new" button to create a new calculation option set. Provide a meaningful name for your new calculation option set and double click it to open the properties. In the properties, set the Calculation Type to Fire Flow. Next, go to Analysis > Scenarios. Create a new scenario by choosing New > base scenario, or right click an existing scenario and choose "child". Provide a name for the new scenario, such as "Automated Fire Flow Analysis". Double-click your fire flow scenario to open the properties. Select your fire flow alternative from the dropdown next to "Fire Flow" and select your fire flow calculation option from the dropdown next to "Steady state/EPS solver Calculation options". Make your fireflow scenario current by right clicking it's name in the scenario manager and choosing "make current" or by selecting it from the Scenario dropdown menu bar at the top of your WaterCAD/WaterGEMS window. At this point, the automated fireflow analysis can be computed by going to Analysis > Compute. To understand the process that WaterCAD/GEMS uses, please see the section further above, entitled "How does the automated fire flow routine work?". Interpreting Automated Fire Flow Results There are several ways you can view the results of your automated fire flow analysis. Below describes the most common. Using the Fire Flow Report Make sure that your Fire Flow Analysis scenario is the current scenario and that you've succesfully computed it. Click Report > Element Tables > Fire Flow Report. The Fire Flow report is essentially a custom flextable including only the relevant fire flow results for both junctions and hydrants. The fields seen here can be added to the junction and hydrant flextables, but it is generally more convenient to use and keep this separate fireflow flextable when reviewing results of an automated fire flow analysis. Note: if you look at the general results in other flextables, such as "pressure" in the junction table, you will be viewing the baseline steady state results for your model, without any fire flow demands present. It is recommended that you only look at the fireflow table, so as not to be confused. The first thing you will notice is a column titled "Satisfies Fire Flow Constraints?" This will be checked only if the particular fire flow node (designated by the "label" for each row in this report) can provide at least the needed fire flow, while satisfying the fire flow constraints - the pressure constraints and sometimes the velocity constraints, if applicable. Here is a description of some of the other fields (columns) available in the fire flow report: Note: if your table does not display one or more of the below fields, you can add it using the yellow "edit" button at the top of the flextable. Is Fire Flow Run Balanced? "If set to true then the fire flow analysis was able to solve". Specifies whether the fireflow run was balanced or not for the given node. Using the Fire Flow Results Browser The Fire Flow Results Browser will allow you to check results for others elements in your model, during individual fire flow runs. Normally, the only results available after a fire flow analysis are the residual pressures at each fireflow node and minimum zone/system pressures. If you'd like to see other results, such as pipe velocities, hydraulic grades, valve status, etc, during a specific fire flow test, you can use this tool. First, you'll need to make sure that you have set up your Fire Flow Alternative for this function before running the fire flow analysis: After you have set up your Auxiliary Output Settings and run the Fire Flow analysis, go to Analysis > Fire Flow Results Browser. Select a fire flow node from the list to see the results for its adjacent pipes, and for the elements included in the output selection set (defined in the fire flow alternative). With a fire flow node selected, you can then establish color coding, annotations or simply check auxiliary results using the elemenet properties or flextables. For example, if you wanted to see the status of Valve X when Hydrant Y was flowed, click Hydrant Y in the list and then open the properties of Valve X. Color Coding Fire Flow Results Another good way to review an automated fire flow analysis is to use color coding. For example, you can color code junctions and hydrant based on the values for total available fire flow, to see areas where the available fire flow is lacking. Another useful color coding could be one based on the "satisfies fire flow constraints?" attribute. For example, you could color code such that junctions with "false" for this attribute show up as red, with a larger size. This would be done by using the "color and size" option, in the color coding dialog. You can also use color coding with the fire flow results browser. For example, you could color code pipe velocities so that when you click fire flow nodes from the fire flow results browser list, the colors will update to show the velocity distribution when that particular node was flowed. Troubleshooting Fire flow results not available In some cases, you may notice that the results in your fire flow report show "N/A" after computing the model. Make sure your scenario is set up correctly. Ensure that the correct fire flow alternative is assigned to the scenario that you are computing and ensure that its calculation options have the calculation type set to "fire flow". If this is set to "hydraulics only", fire flow results will not be computed. Make sure the scenario computed succesfully. If any messages show up under your user notification (Analysis > User notifications) with a red circle next to them, it means that the calculation failed. You'll need to address these fatal errors first, before results will be available. "N/A" entries can also be caused by omission from the fireflow selection set. In your fire flow alternative, make sure that all the nodes you'd like to study are included in the selection set selected for "Fire flow nodes". The fireflow routine will only analyze and provide results for nodes in this selection set. If desired, a filter can be used in the fire flow report so that nodes not included in the fire flow nodes selection set are not displayed. Make sure that you are not trying to use the fire flow results browser, if you haven't set up your fire flow alternative to save auxiliary results. Doing so can cause results in the fire flow flextable to show "N/A". This can be fixed by clicking the "reset to standard steady state results" button at the top of the fire flow results browser. Understanding why a node cannot provide the desired fire flow In the fire flow report (flextable), you may notice that one or more fire flow nodes does not satisfy the fire flow constraints. Meaning, the total available fire flow is less than the needed fire flow or below what you expected. There are several reasons why this could occur. First, check the calculated residual pressure field. This is the pressure at the fire flow node, at the total available fire flow. So, if this is equal to the residual pressure constraint, it means that the residual pressure constraint would be violated if any more flow was passed, so the fire flow routine stopped. If the calculated residual pressure is less than the residual pressure constraint, it probably means that the residual pressure was below the constraint even with the base demands (with no additional fire flow added). In this case, you should check the pressures in the model with baseline demands - they should all be above the constraints entered in the fire flow alternative. Next, check the calculated minimum zone pressure field. This is the lowest pressure out of all nodes in the same zone as the fire flow node in question, at the total available fire flow. So, if this is equal than the minimum zone pressure constraint that you entered, it means that the fire flow constrainted would be violated if any more flow was passed. So, the fire flow calculation stopped and reported the total available fire flow such that this would not be violated. If the calculated minimum zone pressure shows as less than the constraint, it probably means that the pressure somewhere else in that zone was less than the constraint, even with only the base demands (with no additional fire flow added). You should check the pressures in the model with baseline demands - they should all be above the constraints entered in the fire flow alternative. To check which specific node had the lowest pressure in the zone, check the "Junction with minimum pressure (zone)" field. In many cases, this may be a node at the suction side of the pump or at some other location that you may not be concerned with. In this case, it is recommended that you assign a different zone to these nodes. For example, create a zone called "low" and use that. This way, it won't be in the same zone as any fire flow nodes and thus won't be considered (unless you're using the minimum system pressure constraint). If you elected to use the minimum system pressure constraint in your fire flow alternative, you'll also need to check the calculated minimum system pressure. This is identical to the zone pressure constraint (see above), except it checks pressure at ALL nodes in the model. You can also check the "Junction with minimum pressure (system)" field to see which node caused the fire flow routine to stop. If you elected to use the Velocity constraint in your fire flow alternative, you'll also need to check the "Velocity of maximum pipe" and "Pipe w/ Maximum Velocity" fields. If the velocity in any pipe inside the chosen "pipe set" selection set exceeds the constraint you entered, the fire flow routine will stop. So, similar to the pressure constraints, you may notice the "Velocity of maximum pipe" is equal to or less than the constraint, indicating the reason why no additional fire flow could be extracted. Lastly, in rare cases, the fire flow routine may stop at a certain Total Available fire flow due to an unbalanced model. Meaning, at certain flow rates, the steady state simulation may not be able to converge on a balanced hydraulic solution within the maximum number of trials. This can occur in large, complex models, with low or near-zero flows, and/or when other data input in the model is not correct. It causes the results to be invalid and the fire flow run to stop. If your available fire flow is less than the upper limit, yet all the constraints described above are not violated, chances are that this was caused by the network becoming unbalanced. To check, try running a manual fire flow analysis on that junction. For the manual run, just make sure the calculation type in your calculation options is set to “Hydraulics only” and that you have entered the value for the total needed fire flow as an additional, fixed demand on that junction. Run the analysis and check your user notifications for an unbalanced error. One solution to this is to increase the max trials value in the calculation options, but you should also consider investigating other causes, such as data entry errors. Note: be aware of the presence of local fire flow constraints. At the bottom of your fire flow alternative, you can set node-specific constraints, which override the global constraints set at the top. This could potentially cause confusion when viewing fire flow results. For example, the total available fire flow for a certain node may be less than what you believe the needed fire flow value is, but still showing as satisfying the fire flow constraints. If you had a local "needed fire flow" set to a lower value, this could be valid. So, make sure you include and check the "Fire flow (needed)", "Fire flow (upper limit)" "Pressure (residual lower limit)" and "Pressure (Zone lower limit)" fields in your fire flow report/flextable. Consider the following Fire Flow Flextable, with no minimum system pressure or maximum velocity constraints used: J-10 - This node passed the fire flow test, as indicated by the "Satisfies fire flow constraints?" check box. It reports a Total available fire flow of 2012.68gpm, which is above the total needed fire flow of 462.68. Although the needed fire flow is actually 450.00gpm, we have chosen to add fire flows to base demands, and there is a base demand of 12.68gpm on this node. The total available amount of 2012.68gpm accounts for this base demand as well. Meaning, the total demand on this particular node can be up to 2012.68gpm without violating any fire flow constraints. The reason is because at the upper limit (2012.68gpm), both the residual pressure and minimum zone pressure are 59.2psi, which is above the constraints. The fire flow analysis stopped at the upper limit value to prevent unrealistically high flows from being computed. J-169 - This node passed the fire flow test with a reported total available fire flow of 557.82gpm. This is above the needed fire flow but below the upper limit. The reason why the fire flow test stopped at this flow is because a higher flow rate would violate the zone pressure constraint. As you can see, the calculated minimum zone pressure (lower limit) is equal to the user-entered minimum zone pressure constraint of 20psi and the "junction w/ minimum pressure (zone)" shows J-170. This means that although the residual pressure at J-169 (24.3psi) is above the constraints, J-170 is in the same zone as J-169 and had the lowest pressure, 20psi. J-171 - This node passed the fire flow test with a reported total available fire flow of 489.28gpm. This is above the needed fire flow but below the upper limit. The reason why the fire flow test stopped at this flow is because a higher flow rate would violate the residual pressure constraint. Although the minimum zone pressure of 23.5psi is above the 20psi constraint, the residual pressure (calculated pressure at J-171) is equal to the residual pressure constraint of 15psi. At a higher flow rate than 489.28gpm, the residual pressure would drop below 15psi, which would violate the pressure constraint. So, the fire flow analysis reports the maximum flow available without violating the constraint. J-159 - This node failed the fire flow test, as indicated by the unchecked "Satisfies fire flow constraints?". This is because the total available fire flow is 327.06gpm, which is less than the total needed flow of 453.17gpm. The reason why this node can only supply 327.06gpm is because of the residual pressure constraint. As you can see, even though the minimum zone pressure (60.4psi) is well above the zone pressure constraint, the calculated residual pressure is equal to the residual pressure constraint. This means that the pressure constaint would be violated at a flow any higher than 327.06gpm. J-154 - This node failed the fire flow test, because the available fire flow of 289.24gpm is less than the needed fireflow of 455.39. The reason it can only supply this much flow is because of the minimum zone pressure constraint. As you can see, although the residual pressure (28.5psi) is above the constraint, the minimum zone pressure is equal to the constraint, with J-158 as the "junction w/ minimum pressure (zone)". This means that J-158, which is in the same zone as J-154, is preventing any additional flow from being extracted, without violating the minimum zone pressure constraint. J-1 - This node failed the fire flow test with a total available flow of zero. This means that even without any demand at all on J-1, the baseline pressures in the model fall below the constraints. This is indicated by the calculated residual pressure of -1.4psi. This means that with zero demand on this node, the pressure at J-1 is -1.4psi. Since this is well below the constraint of 20psi, the fireflow test fails and the available fire flow is reported as zero. This particular junction is located on the suction side of a pump station, so it probably should be excluded from the fire flow nodes selection set. Meaning, it is probably unnecessary to compute fire flow for this node. J-2 - This node also failed the fire flow test with a total available flow of zero. In this case, it is because the minimum zone pressure constraint was violated. This means that without any demand at all on this node, the pressure at J-1 is -1.4psi. J-1 is in the same zone as J-2 and as seen above, it is at the suction side of the pump. So, assigning a new zone to J-1 should resolve this problem, since it would no longer be considered during the check of zone pressure. J-3 - This node, along with other junctions below it, show "N/A" for all calculated fields. This is because these nodes are not included in the fire flow nodes selection set , set in the fire flow alternative. Fire flow results browser not working If you attempt to use the fire flow results browser tool, you may run into problems if it is not configured correctly. Symtoms could be: Nothing showed up in the list. Some results show "N/A" in the properties/flextables after clicking a fire flow node from the list. This is caused by improper configuration in the fire flow alternative. Open the fire flow alternative and check the "Auxiliary output Settings" section. If you'd like to be able to check auxiliary results for any fire flow node, regardless of whether it passed or failed the "needed fire flow", select "All nodes" for the "Fire flow auxiliary results type". Doing this will ensure that all nodes show up in the list. At this point, at a minimum, you will be able to see auxiliary results for pipes adjacent to the fire flow node that you select in the results brower. If you'd like to see results for more elements, you'll need to choose a selection set for the "Auxiliary output selection set". If you want to be able to see auxiliary results for all nodes, you can create a selection set of all nodes. To do this, close the fire flow alternative, go to Edit > Select All. Right click anywhere in the drawing pane, choose "create selection set" and give it a name, such as "ALL ELEMENTS". Then, select this in your fire flow alternative for the output selection set. Now, when you compute the fire flow simulation, you'll be able to check results for all elements in the model, for your fire flow nodes. Note: the more fire flow nodes available in the list and the more elements included in the output selection set, the longer the calculation will take to perform and the more disk space it's saved results will take up. See Also WaterGEMS V8 Automated Fire Flow FAQ Product TechNotes and FAQs Haestad Methods Product Tech Notes And FAQs [[General WaterGEMS V8 FAQ|General WaterGEMS V8 FAQ]] WaterGEMS V8 Modeling FAQ Hydraulics and Hydrology Forum Whats new in WaterGMES SS6 SCADAConnect Simulator for WaterGEMS SS6 Simulating a Fire Response in SCADAConnect Simulator

Join Bentley's Martin Pflanz online Wednesday, January 18, for the first Bentley Hydraulics & Hydrology Special Interest Group (SIG) workshop of 2017, Building Models from Geospatial Data. Complimentary, one-hour sessions are set for 9 a.m. EST and 7 p.m. EST ; both share the same agenda. Register today ! During this workshop, you will learn how to leverage geospatial data to build functional models complete with pipe information, node elevations, and hydraulic loads. While spending our time in SewerGEMS, the model building features and lessons can also apply to other Haestad software products, such as SewerCAD, WaterCAD, WaterGEMS, HAMMER, CivilStorm, and PondPack. The agenda will include: Building a sewer model from shapefiles with ModelBuilder Importing node elevations with TRex Importing hydraulic loads with LoadBuilder This is a working session, so please feel welcome ask questions! One Professional Development Hour (PDH) will be applied to each attendee’s Bentley Transcript for self-reporting.

Applies To Product(s): Bentley WaterCAD, Bentley WaterGEMS, Bentley HAMMER Version(s): 10.00.xx.xx, 08.11.xx.xx Environment: N/A Area: Layout and Data Input Subarea: Original Author: Scott Kampa, Bentley Technical Support Group Problem Description Can a different model besides water be modeled in WaterGEMS, WaterCAD, and HAMMER? Steps to Resolve WaterGEMS, WaterCAD, and HAMMER are designed to model any Newtonian, single phase fluid. Keep in mind that you may need to change the viscosity and specific gravity depending on the fluid To change this, go to Analysis > Calculation Options. Double-click the active calculation under the "Steady State/EPS Solver" section to open the properties window. Next, find attribute "Liquid Label". You can click the ellipsis ("...") button to open the engineering libraries of available liquids that come with the program. To select one of the available liquids, you can highlight the item and click the "Select" button. If you do not see the liquid you want among the available liquids, you can add new items to the engineering library. Steps to add items to the engineering library can be found at the following link: http://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/modifying-and-adding-entries-to-engineering-libraries.aspx If you want to manually change the liquid or the liquid properties, without going through the engineering libraries. Simply change the values in the calculation options for liquid label, kinematic viscosity, and specific gravity. Note : HAMMER has been used successfully in the past for analyzing certain mining slurries. You need to change the fluid specific gravity and viscosity, and also use a friction factor that is appropriate for the slurry. If it isn’t Newtonian then HAMMER’s standard friction models don’t work very well. This is more of an issue after the initial transient occurs and the resulting pressure waves are being dampened by friction (although it is also a factor to consider when computing the steady state). HAMMER was developed with water in mind. The more you deviate from a specific gravity of 1.0, the more you may need to you engineering judgment to assess the results of the transient analysis. See Also Related Discussion on crude oil What is the difference between pressure head and pressure? When the user changes the fluid, why doesn't the calculated pump head change?

Hello Tushar, HAMMER (as well as WaterGEMS and WaterCAD) are designed to work with Newtonian, single phase fluids. If the liquefied natural gas will act in this manner, it can be used in the product. You would need to adjust the liquid and the liquid properties in the Steady State/EPS calculation options to make sure that the right properties are used. However, HAMMER was designed with water in mind for the fluid in the pipeline. The more you deviate from a specific gravity of 1.0, the more you may need to you engineering judgment to assess the results of the transient analysis. The following link has information on this, including information related to HAMMER: communities.bentley.com/.../10197.can-a-different-liquid-be-modeled-in-watergemswatercadhammer . Regards, Scott

Applies To Product(s): Bentley WaterGEMS, Bentley WaterCAD Version(s): 08.11.XX.XX Environment: N/A Area: Modeling Original Author: Sushma Choure, Bentley Technical Support Group Overview The purpose of this technote is to discuss how to use Darwin Calibrator to perform Leakage Detection. Background Leakage detection is the main criteria in the water loss management. You can perform leakage detection using tool Darwin Calibrator in Bentley WaterGEMS. Using Darwin Calibrator you can predict the location and size of the water loss. To know about format of the input data required for Leakage detection, please search by phrase – Importing Field Data into Darwin Calibrator Using Modelbuilder. Once you have detected the leakage nodes, you can use Criticality tool to repair the leaks. Or you can use Pressure Dependent Demands to minimize the leaks in the system. Note : Along with this technote you will find attached model used to explain Leakage Detection Using Darwin Calibrator & the input data files using Excel Format. Observing leakage over the time with the help of graph using the attached model for a particular element: For this example we have field data of flow through pipe P-13, which we will compare with the model results. (See attached model) Create graph for P-13. (Right click on P-13>Graph) Go to observed data tab>create new. You can directly copy/paste data from the spreadsheet/import .txt file or enter data manually. Once entered the observed data, the graph should look like this. The graph shows the actual flow for Pipe P-13 at various time steps & the observed flow on the field. With the help of this graph you can visualize the leakage at the determined locations, by using the actual flow in the model Vs. observed flow on the field. The difference between the actual flow and the observed flow is the leaked flow into the system. Calibrating the model to observe the leaks in the model Go to Analysis>Darwin Calibrator>Create new Calibration Study>Rename it as Leakage Study. Preparing data for importing the field data snapshots There are several ways of importing the field data into Darwin Calibrator. Using SCADA You need to have SCADA element present in the model for importing SCADA data. 2. Using other file formats as Microsoft Excel Oracle database Microsoft access database Example of data format required using Microsoft Excel. You can prepare data sheet for multiple hours of the day as seen below. Giving an Example of excel spreadsheet for flow through pipes & hydraulic grades at junctions; you can prepare same for other attributes of different elements. You need to import two sheets, one for observed data & second to relate the snapshot labels to the Calibrator & the name of of leakage study. Importing field data through Modelbuilder into Darwin Calibrator Go to Tools>Modelbuilder>New>Excel file. Choose this option as per your input data file. Import the attached excel file through Modelbuilder. Uncheck sheet P-13 , as it contains observed flow data which we already used for creating the graph for pipe P-13. Click next, change the coordinate units as per your model units. Click next until mapping table; map the filed data of hydraulic grades, flows , element labels, time , owner etc. as shown in the image below. Please select Filed data snapshot, observed target as table type for observed data & Field Data Snapshot for Snapshot Labels. Click next once done with the mapping of Modelbuilder, go to Calibrator to check the imported field data. It should look like this. Go to demand groups tab to create group of demands>create new>Select edit button from Element IDs column>select elements from drawing.You can create multiple demand groups as per different pressure zones/Material groups/Diameter groups in the model. ( Please see technote of Darwin Calibrator to know how to create demand groups) Setting up calibrator study for leakage detection Create new optimized run>Rename it as Leakage Detection. In the Demand tab, select Detect Leakage Node in the operation column. Enter the following settings Minimum Emitter Coefficient = 0 Maximum Emitter Coefficient = 0.5 Increment = 0.01 Number of Leakage Nodes = 5 Note: You can change the emitter coefficient values as per the amount of leakage. Go to field data tab, here you can select time steps you want to calibrate, we will select 0 hr for this run. Also you can run the calibration with different combinations of time steps, or all time steps in one go. Compute the Darwin Calibrator once all set. You can increase the number of solutions by going to options>Optimized run. Click on the solution 1 in the left side of the window, you can see the number of leakage nodes detected in the right side of the window. To see which nodes are affected please see the Last column – Adjusted Emitter Coefficient in the Adjustment Groups. Sort the column descending by right clicking on it, to see the affected nodes. Here you can see that junctions J-4 & J-14 are detected as leak nodes having adjusted emitter coefficients of 0.07 & 0.04 , rest all junctions are free from leakage. Now export the results in the form of scenario to visualize in the model. While exporting the results only select Export Emitter coefficients. Viewing the results using Element Symbology Make newly exported scenario as active> Analysis>scenario>Compute the active scenario - New Optimizes Run . Go to Element Symbology>Junction>New color coding. Select Emitter Coefficient as the field name>color & size the elements. You can visualize the leakage elements in the model. See Also http://www.bentley.com/en-us/Solutions/Water%20and%20Wastewater/Water%20Loss/ http://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/5910.using-darwin-calibrator http://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/running-a-criticality-analysis (Please visit the site to view this file)

Hello Joseph, The section "Setting up calibrator study for leakage detection", in the article below, suggests the following settings: Minimum Emitter coefficient = 0 Maximum = 0.5 Increment = 0.01 Number of leakage nodes = 5 Performing Leakage Detection Using Darwin Calibrator

Product(s): WaterGEMS, WaterCAD, SewerGEMS, SewerCAD, StormCAD, CivilStorm Version(s): 08.11.XX.XX and later Area: Modeling Problem How do I save a model in one of the Haestad products integrated with AutoCAD (WaterCAD for AutoCAD, WaterGEMS for AutoCAD, SewerGEMS for AutoCAD, etc...) Solution Normally, when you save a file in WaterCAD, SewerGEMS, WaterGEMS, SewerCAD, CivilStorm, etc... you go on the File menu for the software and save the file with the programs correct extension (.wtg, .swg, .stsw, .swc, etc...). In the case of our products in the AutoCAD environment you will save the .DWG using the AutoCAD menu options. The .DWG file is then linked to the model files for the program you are using.

Product(s): WaterGEMS, WaterCAD, HAMMER, SewerGEMS, CivilStorm, SewerCAD, StormCAD Version(s): 08.11.XX.XX Area: Layout and Data Input Problem How do you open an existing project (from the standalone version for example) in the AutoCAD platform? [Problem ID#: 61067] Solution 1. Open the AutoCAD platform (eg. "WaterCAD for AutoCAD..." shortcut, for WaterCAD). A blank drawing should open. 2. Select the menu item corresponding to the product you're using (eg. "WaterCAD" menu for WaterCAD). 3. Select Import > Hydraulic Model (or Project on older versions) > Import > [Product Name] Database. 4. Browse to and open the model. Note: Any changes made to the model in the AutoCAD platform will be reflected in the standalone version when you save the model. [Solution ID#: 500000081628] See Also What files are necessary to work with a WaterCAD for AutoCAD drawing?

Product(s): WaterCAD, WaterGEMS Version(s): 08.11.XX.XX Area: Output and Reporting Problem When running WaterCAD or WaterGEMS while integrated with MicroStation, the contours on the model are not visible in Print Preview or after printing the model layout. What can I do to make the contours visible when printing the model? [Problem ID#: 36957] Solution To view the contours in the drawing Run the model. Open the WaterCAD/GEMS contour manager (View > Contours). Right-click on the contour and select "Export to DFX" and save it. This new .dxf file will contain only the contours for the model run. Import the DXF into the drawing. The contours should now be displayed for printing. [Solution ID#: 500000063660]

I have a looped system, with 2 points of connection to an existing water main that are modeled as reservoirs. Each reservoir has a GPV. When I run the model I receive an error (Message ID 40005) and flow is showing through the reservoir at 500gpm even though there is no demand proposed for any of the junctions. I don't receive this error when I only have 1 reservoir. Why is the network considered "unbalanced" when there are 2 reservoirs?

Applies To Product(s): WaterCAD, WaterGEMS Version(s): V8i, CONNECT Edition Area: Modeling Original Author: Jesse Dringoli, Bentley Technical Support Group Overview The Air Valve element in WaterCAD and WaterGEMS allows users to accurately model the effects of intermediate high points in a water network. This TechNote describes the effect of using air valves at high points in WaterCAD or WaterGEMS and also compares the implementation of the current capability with modeling approaches used in previous versions. The Trouble with High Points In the past (before the introduction of the air valve element), high points in a pipeline in WaterCAD or WaterGEMS would not be considered for the pump operating point. Basically they would only consider the boundary conditions (reservoirs and tank elevations) in your system. So, the pump will add enough head to lift the water to the downstream known hydraulic grade. It does not consider junction elevations in between and simply calculates a pressure at the junction locations based on the difference between the hydraulic grade and the physical elevation. So, this sometimes resulted in a negative pressure being calculated in the vicinity of the high point. This situation can be seen in the profile below, in which the hydraulic grate line (in red) is lower than the pipe elevation (in green) at the high points. This approach basically simulated the effect of water being siphoned over the high point, which is usually not the case in real systems, since most utilities place air release vacuum breaker valves at the high points, and since the vapor pressure of water limits the height of a potential siphon. Since neither of these factors was accounted for in most pressure pipe models, including older versions of WaterCAD and WaterGEMS, the results typically overestimated pump flow and underestimated head (i.e., the pump ran too far to the right on its curve). Basically the head added by the pump was lower than what would really be necessary to 'lift' the water to the high point In earlier versions of WaterCAD and WaterGEMS (V8 XM and below), it was difficult to implement a workaround to this problem. Some possible solutions included placing a small tank at the high point, controlling flow with a FCV (flow control valve) or using a PSV (pressure sustaining valve) to set the pressure to zero. In many cases, the modeler would simply ignore the negative pressure and accept the pump operating point. However, even with a workaround, modelers sometimes found that the high point may be pressurized for higher flows, as shown below. This situation could prove especially problematic in the case of an extended period simulation demonstrating both flow regimes. The Air Valve Solution WaterCAD and WaterGEMS V8i provide an answer by incorporating a new air valve element. By placing an air valve at the high point, the pump sees the air valve elevation as its downstream boundary condition for instances in which pressure would have otherwise been negative at the high point: Note: The Air Valve element was actually added to WaterCAD and WaterGEMS in the V8 XM release, with version number 08.09.400.34. However, the air valve in this version did not include the special behavior described in this technote; it always acts as a junction during the EPS or steady state simulation. It only operates during a transient simulation, when opening the model in Bentley HAMMER. For instances in which the pipeline functions under pressure/full flow for its entire length (e.g., during the high-flow condition), the pump operating point is correctly based on the downstream boundary condition, similar to the behavior in older versions. When the air valve is open, the hydraulic grade on the downstream side may be less than the pipe elevation. This can be displayed as the hydraulic grade line drawn below the pipe. This should be interpreted as a pressure pipe that is not flowing full. Full flow resumes at the point where the hydraulic grade line crosses back above the pipe. To accurately observe this phenomenon in a profile, you should ensure that the elevation of the junction immediately downstream of the air valve is above the point where full flow resumes. For example if your next-downstream junction is far away and at a low elevation, you may not observe the part-full phenomenon. This is because WaterCAD/WaterGEMS can only report/compute hydraulic grade at nodes, so it can only draw the HGL between them. Troubleshooting Because air valves have the possibility to switch status, they can lead to instability in the model especially if there are many air valves in the system. To improve the stability of the model, it is desirable to force some of the valves closed. This can be done by setting the property "Treat air valve as junction?" to True for those valves that are expected to be closed anyway. For any air valve that you expect to be open and that should behave as described in this TechNote, ensure that you choose "false" for the "Treat air valve as junction?" attribute. If all of the pumps upstream of an air valve are off, the pressure network is disconnected in that area and the model will issue warning messages for all nodes in that vicinity indicating that they are disconnected. In addition, the profile between the air valve and the pumps that are Off will be inaccurate. To make the profile view accurate, you can place an imaginary tank or reservoir on a short branch with a tiny diameter pipe at an Elevation (Initial) equal to the air valve elevation. This tank (which will not contribute significant flow) can eliminate the disconnected system message and correctly represent the fluid in the upstream pipe when the pump is off See Also AWWA Book: M51 Air Valves: Air Release, Air/Vacuum, and Combination, Second Edition WaterGEMS V8 Modeling FAQ

Applies To Product(s): WaterCAD, WaterGEMS, HAMMER Version(s): V8 XM, V8i, CONNECT Edition Area: Layout and Data Input Original Author: Nancy Mahmoud, Bentley Technical Support Group Overview Pressure Dependent Demands (PDD) allows you to perform a hydraulic simulation in which the nodal demands can vary based on changes in nodal pressure. This TechNote describes how to set up a PDD simulation in WaterCAD, WaterGEMS, and HAMMER, and also provides suggestions for PDD input data. Background Some types of water demands are volume-based, in that the demand is independent of available pressure. Examples of volume-based demand sources are washing machines, dishwashers, and toilets. (the same volume is used regardless of the pressure) Other demands are pressure-dependent, meaning water usage decreases with a decrease in pressure. Pressure-based demand examples include showers, sprinklers, and leaks. Typically, water modeling programs assume that all demands are volume-based, and maintain the user-input demand regardless of the calculated available pressure. Although this assumption works well under the normal range of pressure conditions, it loses accuracy if an episode such as a fire or pump outage causes a significant decrease in system pressure. One option for modeling demands that vary based on pressure is to set up model nodes as simple flow emitters, using the emitter coefficient property of the node. Because the flow emitter approach places no upper limit on the amount of water demanded with increasing pressure, it is most useful for determining water consumption by a free-discharge element such as a sprinkler or broken pipe. However, other pressure-based demand types result in no additional consumption once the pressure is above a certain threshold value, such that use of flow emitters in the model could skew water consumption to be unrealistically high in higher-pressure areas. Another limitation of flow emitters is that they will result in calculation of a negative demand, or inflow, when the pressure is negative. WaterCAD and WaterGEMS have a Pressure Dependent Demands (PDD) feature that allows for more control over demand calculation. In many instances where pressure affects water use, the PDD feature will provide a more realistic result than simply placing flow emitters on nodes. Using PDD, you can: Analyze pressure-dependent demands at a single node, subset of nodes, or all nodes Define the reference pressure at which 100 percent of the specified reference demand can be met Define the threshold pressure beyond which an increase in pressure results in no additional demand increase Combine PDD and volume-based demands at individual nodes Determine the actual supplied demand at a PDD node, as well as the demand shortfall Obtain a result of zero for pressure-dependent demands when the pressure is less than or equal to zero Present the calculated PDD and the associated results in a table and graph Setting Up the PDD Function Open the Pressure Dependent Demand menu item Click the New button to create a new PDD function The Function Type can either be Power Function or Piece-wise Linear The Power Function option is used to define the exponential relationship between the nodal pressure and demand. The ratio of actual supplied demand to the reference demand (i.e., percentage of defined nodal demand designated as pressure-dependent) is defined as a power function of the ratio of actual pressure to reference pressure. (Defining of reference pressure and pressure-dependent demand percentage is done in the Alternative, as described in the next section.) Using a power equation for your Pressure Dependent Demands is like you are assuming that each 'demand' in your system acts like an orifice. The orifice equation can be written like this: Q = K*P 0.5 Where Q is flow through the orifice, P is pressure upstream of the orifice, and K is some coefficient (which is a function of orifice area, coefficient of discharge, et c.) You can specify a desired Power Function Exponent. The default value provided is 0.5, which is the exponent used in the orifice equation. By checking the box for "Has Threshold Pressure?" you can define a pressure value that maximizes the computed pressure-dependent demand (i.e., demand remains constant when the pressure exceeds the threshold value). If you do not define a threshold pressure, demand will increase with pressure regardless of how high it is. Since many PDD simulations are focused on the effects of lower pressure conditions, it is often not necessary to define a threshold pressure. See the screenshot below for Power Function: Example: If pressure on J-10 is 40% of the Pressure (Reference) set in the Pressure Dependent Demand Alternative (explained below), then going by the graph above (or by computing 0.40 0.5 ), the demand on that given junction will be 63.2% of what was set initially. In other words, if J-10 had a demand of 100gpm, and the Pressure (Reference) is set to 150psi, then if pressure on J-10 drops to 60psi (which is 40% of the 150psi), the demand will not be 100gpm any more--it will be 63.2 gpm. The Piece-wise Function allows you to manually specify the relationship between reference pressure and demand, as shown in the screenshot below: Example: If pressure on J-10 is 65% of the Pressure (Reference) set in the Pressure Dependent Demand Alternative (explained below), then going by the table above, the demand on that given junction will be 80% of what was set initially. In other words, if J-10 had a demand of 200 gpm, and the Pressure (Reference) is set to 150psi, then if pressure on J-10 drops to 130psi (which is 65% of the 200psi), the demand will not be 100 gpm anymore, it will be 80 gpm. Note: If you are using a piece-wise linear function make sure the changes aren't too abrupt on the curve, otherwise the solver may have a more difficult time arriving at a solution. If you have too abrupt a change you may get a "network unbalanced" user notification. To resolve this you could try to gradually decrease the demand. Create a Scenario that Assigns a PDD Function to an Alternative This section describes how to create and configure a new Scenario and Alternative to run your PDD analysis. Go to Analysis > Scenarios. Create a new Scenario. Double-click on the scenario you just created. Click on the drop-down menu right next to Pressure Dependent Demand. Click on New. Assign a name to the new alternative or keep the default as Pressure Dependent Demand Alternative - 1 Go to Analysis > Alternatives. Expand the Pressure Dependant Demand alternative and double-click on the one you just created. Select the Global Function you created earlier. See screenshot below: Set the Pressure (Reference), or check the Reference Pressure Equals Threshold? box if you want it to apply. Often, the Reference Pressure will be defined as the typical pressure at a node under typical demand conditions. However, if you are analyzing pressure-dependent demands for multiple nodes with significantly different typical pressures, you will need to override this system Reference Pressure on a node-by-node basis, as described in the next section. You can set a percentage of the demand that can be pressure dependent. For example, in that case that J-10 has a demand of 200 gpm, you can set 20% (40 gpm) that will not be affected regardless of pressure changes on that node, and the rest of the 80% (120 gpm) will comply to the Pressure Dependent Demand function. If that doesn't apply, keep Percent of Demand that is Pressure Dependent to 100% Click on Close. Assigning PDD on Specific Nodes To override the PDD settings locally on specific junctions, go to the Junction/Hydrant Tab on the Pressure Dependent Demand Alternative window. Check the box under "Use Local Pressure Dependent Demand Data?" Then, select the Local Function from the drop-down menu (you can also create a different PDD function that can be used on selected junctions). Check the Reference Pressure Equals Threshold? or set the Pressure (Reference), if it applies. You may want to set the Reference Pressures for your nodes equal to their "typical" pressures, as computed in a separate representative Scenario. One way to do this is to: Go to your "typical" scenario, open a junction table, sort it by ID, click the first cell in the Pressure column, hold the Shift key, and click the last cell in the column. Then, CTRL+C to copy the data to your Windows clipboard. Return to your PDD alternative, go to the Junction tab, and right-click and Global Edit the "Use Local Pressure Dependent Demand Data?" column to set all values to TRUE. Sort the junctions by ID. Click the Pressure (Reference) column heading to select the cells in that column, then CTRL+V to paste pressure values from your clipboard. Spot check the pressures to be sure they pasted correctly. Set up Calculation Options You'll also need to set up the Calculation Option for the new scenario you created. Go to Analysis > Calculation Options. Click on New button. Double click on the newly created calculation option. Set Use Pressure Dependent Demand? to True. For Pressure Dependent Demand Selection you can either choose or a Selection Set (with nodes where the PDD alternative will apply to, with all the rest always using their regular demands) you created from that list. Now, assign this Calculation Option to the PDD scenario, by double-clicking on the scenario, then choose the PDD calculation option under the Calculation Option drop down menu. Now you can run the scenario. Additional Resources: Pressure Management and Repair of Pipes - for Active Leakage Control (eseminar) See Also [[General WaterGEMS V8 FAQ|General WaterGEMS V8 FAQ]] Pressure dependent demands and negative pressure Modeling intermittant or closed off demands

Regarding "insulation conditions" - I assume you're referring to modeling the insulation on a pipe, which would effect the temperature of the liquid and possibly the wave speed. For the wave speed part, see Craig's previous response - you'll need to account for that in the wave speed entered for each pipe if it is appropriate. For the temperature part, that can be entered in the liquid properties in the calculation options.