I have a model setup that has a PRV and PSV in series. The PRV opens only if the pressure on side A of the system drops below 40 psi, otherwise it is closed. The model ran fine with the PRV. I then added a PSV to control the pressure on side B of the system. If the pressure dropped below 100 psi then the valve is to close. When I go to Analysis-> validate, no problems are found. However, when I run the model I get warnings saying PSV cannot supply pressure and PSV caused ill-conditioning. I am using this run to see how much fireflows will be increased on side A of the system, however, due to these warnings all fireflows are calculated at zero. Do you have any advice on how to troubleshoot this?
Thank you!
As Scott mentioned, the valves may be set up such that it is impossible to solve the network. Also, check the orientation of the valves. In some cases, a bypass pipe can be placed around the valves to help with convergence. We have a wiki article that explains this a bit more, which I just expanded to include a small example model:
Ill-conditioning User Notification
Regards,
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.