Valworx Water Valve
Description
Valworx Series 5654 Positional Ball Valve from their site: Valworx electric actuated PVC ball valves are typically used to control the flow of water and liquid media compatible with the materials of construction (not suitable for air or gas). Ideal where NSF certified construction is required for potable drinking water as well as other industrial applications.
Electrical Wiring
The Valworx valve is wired with the following wire pairs
24v external DC power supply shown as green / green stripe in the example diagram. Specification sheet shows this draws a maximum of 1 amp at 24vdc.
4-20mA valve control shown as blue / blue stripe in the example diagram. The other end of this wire pair is to the Opto22 controller channel configured for 4-20ma output. This allows the controller to open the ball valve to a 0-100% open position.
4-20mA valve position shown as brown / brown stripe in the example diagram. The other end of this wire pair is to the Opto22 controller channel configured for 4-20ma input. This informs the controller of the actual valve position, and is required for accurate fluid flow control.
Adding the Card to the HMI
To add a Valworx card, press the ⨁ button on the upper right of the Devices screen on the HMI. This opens a panel to select the new card type.
Choose the Valworx flow control card type, and a new card of that type is added to the device card palette.
Card Configuration
Valve Reading - Input mV
This section lets you select the 4-20mV input channel on the RIO for reading the valve position. It is pre-calibrated to 0-100%.
Valve Setting - Output mV
This section lets you select the 4-20mV output channel on the RIO for sending the desired valve position.
Water Flow Reading
This section lets you tie a Water Flow meter to the flow control valve for flow rate control. Select the flow meter you wish to couple with this valve.
Control By
The valve can be controlled by either ball valve open percentage (0-100%) or by water flow rate.
If Flow Rate is selected, a flow meter must be specified in the section above. The following configurations are added if Flow Rate is selected.
Flow Rate Max
Enter the maximum flow rate when the valve is opened at 100%. This is necessary to establish the upper bounds for control and PID tuning.
Flow PID Tuning
The flow valve comes pre-configured with PID tuning parameters. If you wish to fine tune the PID loop for your application, this section lets you adjust the P-Gain, I-Gain, and D-Gain parameters.
The Graph Span section lets you expand the visual graph history points. You may want to do this during tuning, in order to view more PID history. If this is changed to a large number, make sure to change it back to a smaller number after tuning, as it consumes memory in the controller.
Using the Card
The front side of the card displays either valve open % or Flow Rate on the large screen, depending if you have configured % open or flow rate in the settings section.
The following example shows a card configured to be controlled by flow rate. The current flow rate is shown on the large screen, and the target flow rate and valve open % are shown to the right.
Flow rate is controlled by moving the slider at the bottom of the screen to a new target.