Hi,

I have a model that has a negative pressure at J-35, where in ground elevation is at 310m and the resulting hydraulic grade is at 302m only.

I tried replacing J-35 with a Pressure Sustaining Valve (PSV), set the pressure to 20psi, with the aim to have the hydraulic grade at that junction to be equal to the ground elevation which is 310m.

But after doing so, this is the new graph that I am getting, there is now a to and from value of hydraulic grade, from 324m to 302m.

Hope you can enlighten me on this one, maybe I am using PSV incorrectly.

Note that my main aim is to have the hydraulic grade at that point to be equal to the ground elevation which is at 310m.

Thanks in advance.