outage segment with isolation valves

Question

Hello, 
 I have a model with isolation valves referenced to pipes. What I am trying to do is close a set of valves and then see the resulting outage segment highlighted. I understand criticality highlights all of the outage segments, but I would like to define the segment by manually closing valves and then seeing the resulting outage segment highlighted. Is there a way to do this? I'm sure it is something simple that I am overlooking. Your help is appreciated!

Scott Kampa · Accepted Answer

Hello, 
 Assuming you still want to use the Criticality module, you can use the Subset feature. In the Segmentation Scope tab, set Scope Type to "Subset". Select the ellipsis (...) button next to the pulldown menu. This will open a Select toolbar. Use this to manually select the segments you want to look at. 
 Outside of the Criticality module, you could try using element symbology, though this may be a more limited method. For instance, you can set the color coding so that you highlight the closed isolation valve and pipes with zero flow, though other pipes may be picked up by this. The Criticality tool is the simplest method to use for this. 
 Here is a link on how to use Criticality: communities.bentley.com/.../running-a-criticality-analysis.aspx 
 Please let us know if you have any questions. 
 Regards, 
 Scott

Mal Sharkey · Answer

Note that you need to be a little bit careful here using color coding in conjunction with a regular calculation. 
 If you close valves, but there are regular (i.e. not 'pressure dependent') demands assigned to nodes within the outage area, then those demands will be satisfied during a simulation. This is because, by default, the solver assumes that the user-entered demands are correct and it uses them as input to calculate things like pressures, pipe flows, etc. 
 Of course it doesn't make sense to satisfy a demand in an area suffering an outage, so as a result you can get some odd looking results. 
 There are ways around this - for example by setting up a 'pressure dependent demand' analysis, or manually removing demands in the outage area - but those options can take some time to set up. 
 Alternatively, I would recommend using the Find Segment by Element tool within the Criticality window. See the attached video for an example. In it I click on an element to find the segment(s) associated with that element, then highlight the related outage segment (based on the same number in the label) to see which pipes are taken out when this segment is closed. (View the video in fullscreen mode for the best image quality.) 
 
 Regards, 
 Mal

Jesse Dringoli · Answer

A couple more thoughts on this: 
 If you're OK with the segments that the Criticality tool is generating, you can highlight them individually by ensuring that the "highlight selection" button is clicked, then click the segment name in the list, then click the Refresh button.

If you want to override the elements used as the boundaries between segments, you can do this in the Options tab. Either use only a specific valve type (such as isolation valves) for the valves you would like to close, selecting "do not use" for all the others, Or, select "do not use" for all the valve types, then use the Valve Overrides at the bottom to select the specific valves that you'd like to close. You can then use the above steps to highlight that particular segment in the drawing.