Applies To
	Product(s):	SewerGEMS, SewerCAD, StormCAD, CivilStorm, WaterGEMS, WaterCAD, HAMMER
	Version(s):	V8i, CONNECT Edition
	Area:	Output and Reporting
	Original Author:	Scott Kampa, Bentley Technical Support Group

Problem

One of the following problems is occurring with flow arrows:

1) Flow arrows are showing even though they are turned off in Element Symbology

2) The flow arrows on pipes or conduits in a model are pointing in the wrong direction.

Steps to Resolve

For the storm and sewer products, first make sure that the start and stop nodes are correct. For the water products, note that a negative flow indicates that the flow is opposite to the orientation of the pipe (per the start and stop node designation).

For a pipe whose flow arrow is pointing in the wrong direction (not the actual direction of flow), try the following:

1. Check the actual flow value in the pipes to see if it is correct. If you find that flow is going the opposite direction than you expect (and that the flow arrows are actually correct), check for user notifications that indicate a calculation problem (such as "network unbalanced" for WaterCAD/WaterGEMS/HAMMER) or other issue that could cause bad results. Graph flow in the pipe to see if it unstable, and correct instability in SewerGEMS and CivilStorm using the following articles: SWMM Solver / Implicit Solver
2. If the flow is near-zero, note that numerical noise can cause the flow arrows to display. If you're running an unsteady/EPS simulation, try advancing forward in time with the TIme Browser.
3. Close the model, but leave the program open. Next, go to File (or Tools, for V8i) > Database Utilities > Compact Database. Select the model's database file and choose the option to "purge". When this process is completed, open the model and compute it.

For the case where flow arrows show even though they are disabled in element symbology (show flow arrows = false), there is a known issue (reference #779863)that can cause this to occur when switching scenarios, when there are active topology changes between the scenarios. The workaround is to toggle the "show flow arrows" option in element symbology twice (turn it on and then off again). This issue has been resolved starting with CONNECT Edition Update 1 of the water products (10.01.00.72). See this article for how to update.

See Also

How can I remove or display pipe flow arrows?