Applies To
Product(s):	WaterCAD, WaterGEMS
Version(s):	08.11.XX.XX and higher
Area:	Modeling

Problem

When using controls to open and close a PRV, PSV, FCV or TCV, there is only the option to set the status to Closed or Inactive. How can a control be set to make the valve active again, to resume controlling the pressure or flow? (or resume applying a headloss or discharge coefficient, for a TCV)

Solution

To make a PRV, PSV, FCV or TCV inactive or closed for a given condition, you would use the valve status Action.

To make it active again (throttling / partially open), use the valve setting Action (such as "TCV Setting"), and set it to the desired hydraulic grade or flow setpoint (of headloss coefficient for a TCV). For a PRV or PSV, you can also set the "pressure valve pressure" to set the pressure instead of the hydraulic grade.

Note: as of version 2024, 24.00.00.24, the "TCV Setting" only applies to TCVs that use the Headloss coefficient type. For TCVs that use the Discharge Coefficient or Valve Characteristics Curve option, adjusting the Cv or percent value (respectively) directly via a control action is not currently supported. You would need to determine the equivalent headloss coefficient setting and set the controls accordingly. This can be found as a calculated value in the Results section of the TCV properties, after computing steady state or EPS.

Example

To close the PRV or PSV

If Tank Elevation > xx ft. (m), Then PRV Pressure Valve Status = Closed.

To make the PRV active:

If Tank Elevation > xx ft. (m), Then PRV Pressure Valve Pressure = yy psi (or Then Pressure Valve Setting = yy ft.)

To open a TCV to a headloss coefficient of 3.0:

IF Tank Elevation >xx ft/m THEN TCV-1 TCV Setting = 3.0

How can I make a PRV, PSV, FCV or TCV valve active after closing it with controls?

Problem

Solution

Example

See Also