Analysis and Solutions for Common Faults of Vortex Flowmeters:
1. Stable indication but large flow difference
• Reason: Incorrect settings in PLC or DCS programs, such as using square root operation for differential pressure flowmeters, or incorrect temperature-pressure conversion formulas.
• Solution: Check configuration settings, correct formulas, and ensure no square root operation is used.
2. Intermittent measurement abnormalities
• Phenomenon: Zero indication at low flow rates, normal at high flow rates.
• Reason: The lower limit setting of the flowmeter is too high or the pipe diameter is too large, resulting in the removal of small signals.
• Solution: Adjust the lower limit setting or replace with a suitable flowmeter diameter.
3. Increased error at high flow rates
• Reason: High flow rate causes "wave leakage" (missing count of vortex), and long-term overloading may damage the sensor.
• Solution: Replace with a larger diameter or a flowmeter with a higher measurement upper limit.
4. Displaying values when no flow
• Reason: Interference signals (such as electromagnetic or vibration interference) are mistakenly identified as vortex signals.
• Solution: Install a isolator, improve stability, or reduce sensitivity. Be careful not to discard the true flow signal.
5. Abnormal fluctuation in indication values
• Reason: Insufficient straight pipe length, eccentric installation, foreign objects in the pipeline, or interference from gas-liquid two-phase flow disrupting the formation of Karman vortex.
• Solution: Check straight pipe length, correct installation deviation, clean the probe and pipeline.
6. Inaccurate indication values when flow changes
• Reason: Vibration or electromagnetic interference signal strength exceeds the maximum flow signal, or the measurement lower limit does not match the operating conditions.
• Solution: Optimize vibration reduction measures, shield interference, and adjust the lower limit setting.
Application Notes and Challenges
1. Challenges of Large Diameter and Low Flow Rate
• Problem: When dealing with large-diameter pipes or low flow rates, the vortex frequency may be confused with the fluctuating frequency of the flow velocity, resulting in measurement errors.
• Suggestion: Select a flow meter suitable for the diameter or optimize the pipeline design to stabilize the flow field.
2. Built-in Pressure Detection Error
• Problem: Severe changes in the flow field cause the pressure detection to be inconsistent with the actual static pressure of the pipeline, and the error is related to flow rate, density, and viscosity.
• Suggestion: Calibrate the pressure detection or verify the error range through experiments.
Analysis and Summary of Turbine Flowmeters:
Turbine flowmeters, with their high accuracy, low maintenance requirements, and wide applicability, have become the preferred equipment for industrial flow measurement. Correct installation and regular maintenance can significantly enhance their performance. For common faults, specific conditions such as the working environment, pipeline conditions, and interference factors need to be considered to ensure accurate measurement and equipment lifespan.
Post time: Jul-17-2026