Common Faults and Solutions of Vortex Flowmeter

As a flow measurement instrument widely used in the industrial field, vortex flowmeter plays an important role in many industries such as chemical industry, electric power, metallurgy, etc. However, in actual use, it may have various faults, affecting the accuracy and stability of measurement. The following will introduce the common faults of vortex flowmeter and the corresponding solutions in detail.
Ⅰ. No signal output failure
1. Sensor installation problem
Improper sensor installation position is one of the common reasons for no signal output. If the sensor is installed at the bend of the pipeline, near the valve, or in an area where the fluid has strong pulsation, the flow state of the fluid will be disturbed, making the vortex flowmeter unable to accurately detect the vortex signal. The solution is to reselect a suitable installation position. Generally, the length of the upstream straight pipe section of the sensor is required to be no less than 10 times the pipe diameter, and the length of the downstream straight pipe section is required to be no less than 5 times the pipe diameter to ensure that the fluid can flow smoothly in the sensor measurement area.
2. Connection line failure
If the connection line has problems such as open circuit, short circuit or poor contact, the sensor will also be unable to transmit the signal to the converter. At this time, it is necessary to check the connection line to see if the line is damaged or broken, and whether the joints are firm. For open circuit lines, new cables should be replaced; for joints with poor contact, reconnect them to ensure reliable line connection.
3. Sensor damage
The sensor's detection element may be damaged due to long-term use or harsh environment. For example, the piezoelectric crystal is impacted or aged and cannot generate electrical signals normally. To determine whether the sensor is damaged, you can use professional testing equipment to test the sensor. If it is determined that the sensor is damaged, you need to replace it with a new one in time.
Ⅱ. Faults with large measurement errors
1. Fluid parameter changes
The measurement accuracy of the vortex flowmeter is closely related to the density, viscosity and other parameters of the fluid. When these parameters of the fluid change and the flowmeter does not make corresponding compensation, the measurement error will increase. For example, in the chemical production process, the composition of the fluid changes, and its density and viscosity will also change accordingly. The solution is to recalibrate and set the parameters of the flowmeter according to the changes in the actual fluid parameters, or use a vortex flowmeter with automatic compensation function to compensate in real time according to the changes in fluid parameters to improve the measurement accuracy.
2. Impurities or scaling in the pipeline
Impurities, dirt or scaling in the pipeline will affect the flow state of the fluid, interfere with the formation and propagation of the vortex, and cause measurement errors. Regular cleaning and maintenance of the pipeline is an effective way to solve this problem. Chemical cleaning or mechanical cleaning can be used to remove impurities and scaling in the pipeline to ensure that the inner surface of the pipeline is smooth and the fluid can flow normally. At the same time, install a filter at the entrance of the pipeline to prevent large particles of impurities from entering the flowmeter measurement area.
3. Inaccurate flow meter calibration
If the vortex flowmeter is not properly calibrated after installation, or has not been calibrated for a long time, its measurement accuracy will also decrease. The vortex flowmeter should be calibrated regularly in accordance with relevant standards and specifications. Calibration can use a standard flow device to compare the flowmeter's measured value with the standard flow, and adjust the flowmeter's parameters so that its measurement error is within the allowable range.
Ⅲ. Display Unstable Failure
1. External Interference
During operation, the vortex flowmeter may be affected by external electromagnetic interference, mechanical vibration, etc., resulting in unstable display. For example, there are strong electromagnetic fields generated by large motors, transformers and other equipment nearby, or there is severe vibration in the pipeline. In order to reduce electromagnetic interference, shielding measures can be taken for the signal transmission line of the flowmeter, and the shielding line can be reliably grounded. For mechanical vibration problems, check the support and fixation of the pipeline to ensure that the pipeline is firmly installed to reduce the impact of vibration on the flowmeter. If the vibration problem is more serious, a shock absorber can be installed near the flowmeter.
2. Converter Failure
The converter is a component that amplifies, processes and displays the weak electrical signals detected by the sensor. If the circuit components inside the converter fail, such as amplifier damage, filter circuit abnormality, etc., the signal processing will be unstable, resulting in unstable display. At this time, professional technicians are required to repair the converter and replace the damaged circuit components. During the repair process, pay attention to electrostatic protection to avoid secondary damage to the converter.
Ⅳ. Flow value is abnormally large or small
1. Zero point setting error
If the zero point setting of the vortex flowmeter is inaccurate, the flow value will be abnormal. During the installation and debugging process, if the zero point is improperly set, such as the zero point offset is too large, the measured flow value will be larger or smaller than the actual flow value. The solution is to re-calibrate the zero point to ensure that the zero point is set correctly. Zero point calibration generally needs to be performed when the fluid in the pipeline is static, and the corresponding settings are made according to the flowmeter's operating manual.
2. Flow coefficient error
The flow coefficient is an important parameter for the vortex flowmeter to calculate the flow rate. If the flow coefficient is set incorrectly, it will directly lead to deviations in the flow calculation results. The flow coefficient is related to the structure of the flowmeter, fluid characteristics and other factors. Different flow meters have different flow coefficients. During installation and use, ensure that the flow coefficient is set accurately. If you are unsure about the flow coefficient, you can refer to the product manual of the flowmeter or consult the manufacturer's technicians.
In summary, vortex flowmeters will encounter various faults in actual operation. By analyzing common faults and taking corresponding solutions, faults can be eliminated in time to ensure the normal operation of the vortex flowmeter, improve the accuracy and reliability of flow measurement, and provide strong guarantees for industrial production. In daily use, the maintenance and management of vortex flowmeters should also be strengthened, regular inspections and calibrations should be carried out, potential problems should be discovered and handled in time, and the service life of the flowmeter should be extended.