How does the Pressure Reducing valve (PRV) work?
A pressure reducing valve (PRV) will throttle the flow to prevent the downstream pressure or hydraulic grade from exceeding a user-defined pre-set value. In order to achieve its pressure reducing ability, a specific headloss will be induced through the PRV, such that the resulting downstream pressure obeys the setting. The valve can be in one of three states: Valve is CLOSED if downstream pressure exceeds the pressure setting or is greater than the upstream pressure (to prevent reverse flow). Valve is OPEN if upstream pressure is less than setting and downstream pressure is less than upsteam pressure. Valve CONTROLS if upstream pressure is greater than setting and downstream pressure equals setting.
