How does the Pressure Sustaining valve (PSV) work?
A pressure sustaining valve (PSV) tries to maintain the upstream pressure or hydraulic grade at a user-defined pre-set value. In order to achieve its pressure sustaining ability, a specific headloss will be induced through the PSV, such that energy balance across the model results in the upstream pressure obeying the setting. The valve can be in one of three states: – Partially opened (i.e., active/throttling) to maintain its pressure setting on its upstream side when the downstream pressure is below this value. – Fully open (inactive) if upstream pressure exceeds setting or if the downstream pressure is above the setting. – closed if upstream pressure falls below setting or if downstream pressure exceeds upstream pressure.
