Negative pressure when flow is zero

Question

Hi, 
 I have a dma which is fed from one single source. This dma only got supply for 8hrs. However when i run the model it showed huge negative pressure when flow is zero. Could someone advise why this is happening and how to solve this problem.

Sushma Choure · Accepted Answer

Hello Azizah, 
 Here is the support solution which speaks about the reasons behind negative pressure. 
 communities.bentley.com/.../10830.negative-pressures.aspx 
 If this doesn’t help you, then we would need a copy of your model. 
 There are two options for sharing your model files on BE Communities. If you would like the files to be visible to other members, compress the files into a zip file and upload them as an attachment using the ‘Advanced Reply editor’ before posting. If your data is confidential, you can follow the instructions in the link below to send it to us via Bentley Sharefile. Files uploaded to Sharefile can only be viewed by Bentley. 
 communities.bentley.com/.../bentleysecurefilesupload.aspx 
 If you upload the model to Sharefile, please post here letting us know, so that we know that it is available. 
 Regards 
 Sushma Choure 
 Technical Support Group

Jesse Dringoli · Answer

It may also help to explain a bit more about "when flow is zero". Are you attempting to compute the model at "static" conditions with zero demands (this tends to make it difficult to balance). Are you looking at a system head curve? (demands will need to be pressure dependent if there's no storage in the dma). Both of these topics have been discussed before, so you can find some additional information by doing a search. 
 If your case is neither of the above, then as Sushma mentioned, it may be best to see your model to understand and explain.