Hi,
The model I'm working on is divided in two primary sections.
Section 1 is fed by a reservoir pumped into a PSV and a PRV in serie. The goal of the PSV in this case is to limit the maximum pumped value to 2300 lpm with a 92 meters of head and the PRV limits my head to 92 also to avoid pressures being too high on downstream nodes.
A single line leads to the Section 2 of the distribution network. I have a pump in this section that allows the reservoir in the first section to fill a tank at higher altitude.
Once the tank is at a certain level, the pump in Section 2 is closed, a pipe is opened to allow reverse flow at the pump location and the pump at my reservoir is closed to allow the whole system to be fed by the water tank. Once a certain level is reached, the pumps are started again and the pipe is closed to allow the refill of the water tank.
The system works fine as long as I keep the PSV inactive. Once I activate it, the PRV cannot supply pressure and the system becomes unbalanced. Considering that the sum of my demands is under 700 lpm, I'm not sure what could cause this issue.
Note: I'm working on an EPANET model that was converted to WaterCAD
Are you trying to model a combination PRV/PSV? If so, please take a look at the following article I just created and let me know if that configuration will accurately model what you want.
How to model a Combination Pressure Reducing Valve (PRV) and Pressure Sustaining Valve (PSV)
Regards,
Craig Calvin
Bentley Technical Support
Please provide your model and let me know which PRV and PSV you are referring to.
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Here are some things you may want to consider:
After making the above changes, all time steps balance with much less trials. I sent you a PM with a link to download a modified version of your model.