<< Click to Display Table of Contents >> Navigation:  Wadiso 6 User Guide > Steady state analysis  > Definitions of steady state analysis terms > Pressure Reducing Valve

A pressure reducing valve (PRV) is a link. The pressure setting for a PRV is the pressure above ground level, which the valve will try to maintain on the downstream side of the PRV. If the downstream pressure can be maintained at the pressure setting, the valve is ACTIVE. If the upstream pressure is less than the pressure setting, the valve is completely OPEN. If, for some reason, the downstream pressure exceeds the valve setting, the valve is CLOSED. PRVs also act as check valves (i.e. reversed flow is not possible). In this case, the valve is CLOSED. The operational mode of the PRV (OPEN, ACTIVE, CLOSED) is indicated in the results viewers. A PRV link has no length associated with it. Although it is not a specific requirement, elevation of the beginning and ending nodes of the PRV link should be the same. Flow direction is from beginning node towards ending node.

 

Two PRVs cannot have the same ending node. The ending node of a PRV cannot be the beginning node of another PRV. In these cases, the two PRVs must be separated by a pipe, no matter how long or short. In general, for improved mathematical stability of the network solver, the beginning and/or ending nodes of a PRV should not coincide with the beginning or end node of any other special link types, such as check valves, pumps, and flow or pressure control valves.