Troubleshooting Guide for Vortex Flow Meter Problems

• Vortex flow meters are essential instruments utilized across a wide range of industrial applications to quantify fluid flow rates. 
• They may, however, experience problems that require for troubleshooting, just like any other measurement equipment.
• This guide provides a detailed overview of common problems associated with vortex flow meters, the reasons behind these issues, a comprehensive troubleshooting process, and recommended solutions.

 Vortex Flow Meter Problems and Troubleshooting

Symptom 1: No Display

Explanation:

• Power Supply Failure: In cases of a power supply failure, the flow meter won’t display data. To identify this issue, test the voltage on the power source using a universal meter. If the voltage is too low or absent, the solution is to re-wire the power or use a new power source.
• Power is Not Wired: If power is not properly connected, the meter will not display any data. Testing the voltage on the power source can help determine the issue. To resolve it, wire the power correctly.
• Cable is Broken: A damaged cable can disrupt the flow of information from the sensor to the display. Check the cable for any signs of damage, such as break-off points. If damaged, replace the cable and re-wire it.
• Wrong Wiring: Incorrect wiring can lead to the absence of a display. Ensure the wiring is correctly connected to the appropriate terminals to address this problem.

How do you troubleshoot a vortex flow meter?

 Symptom 2: Displayed Flow Rate is Zero while there is flow in the Pipe

Explanation:

• Flow Rate is Lower Than the Meter’s Lower Limit: If the flow rate is below the lower limit of the meter, it may not register any flow. To test this, increase the flow rate and observe the meter’s response. If it doesn’t respond, consider using a flowmeter suitable for the application.
• The Flow Rate of Small Signal Cut Off Function is Too High: An incorrect setting may cause small signal cut-off at a flow rate higher than the actual flow. In this case, adjusting the small signal cut-off setting to an appropriate value can resolve the issue.
• Energy Threshold Value is Too High: When the energy threshold value is set too high in spectrum analyzing checking mode, it can result in a zero flow rate reading. Refer to the manufacturer’s guidelines to set the energy threshold value at an appropriate level.
• Transmitter Function Failure: If the transmitter is malfunctioning, it can lead to inaccurate readings. To identify this, replace the transmitter with another of the same type and check if the issue persists. If so, replace the transmitter.
• Sensor is Damaged: Before replacing the sensor, increase the flow rate and observe any changes in the reading. If the problem persists, replace the sensor as it may be damaged.
• Pipeline Blocked or Sensor Jammed: If none of the above possibilities explain the issue, inspect the pipeline and the flow meter’s installation. If blockages or sensor issues are detected, re-install the flowmeter.
• Incorrect 4–20 mA Output Problem: Ensuring the correct installation of the meter with the arrow indicating the direction of process flow is essential to address this issue. Additionally, verify and correct the configuration parameters, check sizing accuracy, and conduct electronics verification to ensure accurate flow measurements.

What is the error of vortex flow meter?

Symptom 3: The flowmeter has flow reading while there is no flow in the pipe

Explanation:

• Power Frequency Interference: If power frequency interference is present, it can result in inaccurate readings. To address this issue, check the frequency display on the meter. It should be stable and match the power frequency. If not, re-wire the meter with shielded cable according to the manufacturer’s requirements.
• High Voltage Instrument or High-Frequency Interference: Nearby high-voltage instruments or high-frequency interference can disrupt the flowmeter’s performance. Check for the presence of such equipment, and if interference is detected, relocate the flowmeter to an area without interference.
• Heavy Vibration on the Pipeline: Excessive vibration can lead to inaccurate flow measurements. To identify this, sense the vibration on the pipeline by touching it. If vibration is excessive, tighten the pipeline where the flowmeter is installed to reduce movement.
• Valve is Not Closed Properly: Improper valve closure can allow flow when it should be shut. Check the pressure and confirm that the valve is properly closed and sealed. If necessary, the valve should be repaired or replaced.

Symptom 4: The flow rate reading fluctuates significantly

Explanation:

• The Gasket and the Pipe are Not Concentric: Misalignment between the gasket and the pipe can lead to erratic flow readings. Check the position of the gasket, and if it’s not aligned correctly, re-install the gasket.
• The Flowmeter Pipe Body and the Pipeline are Not Concentric: Lack of concentricity between the flowmeter pipe body and the pipeline can result in fluctuating readings. Verify if they are aligned correctly, and if not, re-install the flow meter.
• Straight Pipe Length Not Enough or the Inner Diameter of Flowmeter Pipe Body Does Not Match the Pipeline: Inadequate straight pipe length or a mismatch between the flowmeter pipe body’s inner diameter and the pipeline can lead to flow rate fluctuations. Check both parameters and consider re-locating the flowmeter if necessary.
• Heavy Vibration on the Pipeline: Excessive vibration can disrupt flow measurements. Sense the vibration on the pipeline by touching it. If vibration is excessive, tighten the pipeline where the flowmeter is installed to reduce movement.
• The Fluid has Not Filled the Pipeline Fully: In cases where the fluid doesn’t fill the pipeline completely, it can result in erratic readings. Check the fluid status and the meter’s location, and consider re-locating the flowmeter if necessary.

Symptom 5: There is a big difference between the flow reading and the Process flow rate

Explanation:

• No Density Compensation for Steam Measurement: If there is no density compensation for steam measurement, it can lead to significant differences between flow readings and the actual process flow rate. Check the density compensation devices and settings to establish proper density compensation.
• The Estimated Flow Rate Before Using the Meter is Wrong: In cases where the estimated flow rate is incorrect, use another flowmeter to verify the actual flow rate and make necessary adjustments.
• Parameter Setting Incorrect: Incorrectly configured settings, such as meter K factor, upper and lower limits of flow rate, can result in a substantial difference between the flow reading and the actual process flow rate. Ensure the meter settings are correctly configured.

Symptom 6: Communication problems with a HART based Communicator

Explanation:

• Low Voltage at Transmitter Terminals: Inadequate voltage supply at the transmitter terminals can cause communication problems. Verify that the voltage at the transmitter terminals is at least 10.8 Vdc to resolve this issue.
• Communication Loop Issues with HART-Based Communicator: Any issues within the communication loop involving a HART-based communicator can disrupt communication. Investigate and fix these loop issues.
• Loop Resistor Value and Power Supply Voltage Discrepancies: Discrepancies between loop resistor value (Rloop) and source power supply voltage (Vps) can lead to communication problems. Ensure that [Vps – (Rloop x 0.024)] exceeds 10.8 Vdc.
• Transmitter in Multidrop or Burst Mode: If the transmitter is incorrectly configured in multidrop or burst mode, it can result in communication issues. Adjust the transmitter to the appropriate mode for communication.
• Three-Wire Pulse Installation: In the case of a three-wire pulse installation, removing the pulse connection can rectify the communication problem.
• Electronics Replacement: If none of the above solutions address the communication problems, consider replacing the electronics as a last resort.

Symptom 7: Incorrect 4–20 mA Output

Explanation:

• Low Voltage at Transmitter Terminals: A low voltage supply at the transmitter terminals can lead to incorrect 4–20 mA output. Ensure that the voltage supplied to the transmitter terminals is at least 10.8 Vdc or higher.
• Configuration Discrepancies: Incorrect configuration settings, including URV, LRV, Density, Special Units, and LFC, can result in discrepancies in the 4–20 mA output. Ensure these settings match the specifications provided by the sizing program.
• 4–20 mA Loop Test: Performing a 4–20 mA loop test helps verify that the output is within the expected range. Conduct this test to confirm the output’s accuracy.
• Corrosion on Terminal Block: Corrosion on the terminal block can disrupt electrical connections, leading to incorrect 4–20 mA output. Remove any corrosion and ensure a clean, solid connection.
• Electronics Replacement: In cases where other solutions don’t resolve the issue, replacing the electronics may be necessary.

Symptom 8: Problem with Sensor

Explanation

• Coaxial Sensor Cable Condition: Inspect the coaxial sensor cable for any cracks or damage and replace it if necessary to maintain proper sensor functionality.
• Sensor Impedance at Process Temperature: Ensure that the sensor impedance at the process temperature exceeds 1 Mega-Ohm. If it falls below this value, consider replacing the sensor for accurate measurements.
• Sensor Nut Torque: Verify that the torque on the sensor nut aligns with the specified values, which can vary based on the meter body size and flange type.

If the problems you are experiencing are not addressed in the common troubleshooting scenarios provided, consider consult the manufacturer’s guidelines for further assistance. Manufacturer’s guidelines troubleshooting instructions may involve more complex diagnostic procedures and specialized equipment to pinpoint and resolve specific issues.