Two options are specific to calibrating Smart Valve hardware.
- Calibrate Torque
Torque is a measure of how much stress is on the valve stem, and is only useful for a TOTS valve as an indication of how hard the disc is forced against the seat. The controller will turn off the motor when the torque reaches the configured torque limit. Torque will read close to zero when the motor is not energized and the valve is not closed. Torque will read a small positive or negative percentage while the motor is opening or closing the valve before it gets into the seat zone. Only when the plate starts to connect to the seat do the torque readings quickly ramp up towards +/- 100%.
- Calibrate Pressure
There is a pressure transducer on each side of the valve which directly measures fluid pressure and produces a voltage. No part of the pressure calibration is concerned with flow rates. Flow rate is calculated in the operator based on pressure differentials. The pressure calibration deals with percent of maximum gauge and differential pressures.
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- Calibrate Pressure
Calibrate Torque
Calibration cannot take place unless a connection is present between the Design Pad Schema Viewer PC and the valve. This can be accomplished with an I/R wand or, in this case, an Ethernet connection as indicated by the green box at the bottom of the dialog.
Torque Sensor Voltage displays the electrical current, in milliVolts, corresponding to the current position of the valve.
The numbers tend to be smaller (more negative) while closing and larger (more positive) while opening.
Calibrated Torque displays the percentage open or closed at which the valve is currently positioned.
The Calibration Values are set by opening and closing the valve, and by setting it to 30% open or closed. At each valve setting, press , is the voltage measured from the torque sensor (in milliVolts) corresponding to the current load applied to the sensor.
Calibrated Torque displays the load applied to the torque sensor as a percentage of the actuators maximum torque value. Negative values correspond to closing torques. Positive values correspond to opening torques.
Calibration Values are set by applying a known torque to the actuator output (-100%, -30%, +30% and +100%). Pressing the Set button to record the
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voltage (in milliVolts) corresponding to
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each applied torque. Once the values are set
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, they
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must be
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downloaded to
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the actuator by pressingSave to Hardware.
NOTE: This method is intended for factory use only and should not be used in the field unless valid torque values can be applied to the actuator output.
Save to Hardware. Pressing this button will download the Calibration Values to the actuator. This action will overwrite any existing values stored in hardware.
NOTE: If the old values are to be saved they can be retrieved and then stored by first using the Upload from Hardware then Save to File options.
Load from Hardware will upload the current calibration values stored in the actuator and display them in Calibration Values. Once loaded the Calibrated Torque value will display the correct percentage torque. The uploaded values can then be saved to file for later use.
Save to File. Pressing this button will save the values displayed in Calibration Values to a file. The user will be prompted for a file name prior to saving.
Load from File. Calibration valuesstored via the Save to File option can be retrieved by pressing this button. The user will be prompted to select a file from a File Open dialog. The loaded data will be displayed in Calibration Values and can be then downloaded to the hardware.
Calibrate Pressure
The calibration values are shown in two tabs, Gauge Pressure and Differential Pressure.
The current values are displayed at the top of the dialog. Fluid pressure at sensor A and B are displayed in milliVolts, along with the calibrated pressure in pounds per square inch and the percentage of the valve's maximum pressure load associated with the current reading The difference between those readings in displayed below the raw current measurements
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Selecting the Differential Pressure tab shows this dialog:
Connect the valve to a fluid source to calibrate its differential pressures, the difference between measurements at sensor A and B, at each flow setting. As each range is reached its Set button becomes active. Set the calibration value for each pressure value and press Save to Hardware to upload the values to the valve. Press Save to File to create an archive for use if the electronics are replaced. Load the file's values by pressing Load from File. Query the current calibration settings from the hardware by pressing the Load from Hardware button.