Analysis of common field failure phenomena in ultrasonic flowmeters

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　　The common field failure phenomena of ultrasonic flowmeters mainly include: abnormal flow velocity display and drastic fluctuations in data； The reading is incorrect ； The sensor is fine, but the flow rate is low or absent ； When the control valve is partially closed or the flow rate is reduced, the reading increases instead. 　　On-site fault phenomenon: Abnormal flow rate readings with drastic fluctuations ； On-site cause analysis: The sensor is installed in areas where the pipeline vibrates heavily or downstream of devices that change the flow pattern (such as control valves, pumps, and throttle orifices). Solution: Install the sensor in a location far away from the source of vibration, or move it upstream of the device that alters the flow pattern.
On-site fault symptoms: Incorrect readings. Analysis of the causes of on-site faults: A. Sediments at the top and bottom of horizontal pipes where the sensor is installed interfere with the ultrasonic signals. B. The sensor is installed in a pipe with fluid flowing downward, and the pipe is not completely filled with fluid. Correct handling method: A. Install the sensor on both sides of the pipe. B. Install the sensor on the pipe section filled with fluid. 　　On-site fault phenomenon: The ultrasonic flow meter sensor is fine, but the flow rate is low or non-existent. Analysis of the cause of the on-site failure: A. The paint and rust on the outside of the pipeline were not removed thoroughly. B. The pipe surface is uneven or installed at a weld seam. C. The pipe has poor roundness, an uneven inner surface, and lining-scale buildup. This situation may occur if the pipe is made of cast iron. D. The medium under test is a pure substance, or the solid suspension content is too low. E. The sensor is installed on the fiberglass pipe. F. Installing the sensor on the sleeve will weaken the ultrasonic signal. G. The sensor is not properly coupled to the pipeline; there are gaps or bubbles at the coupling surface. Correct handling method: A. Clean the pipeline again and install the sensor. B. Smooth the pipe or move it away from the weld. C. Choose pipe materials such as steel pipes with smooth inner surfaces, or areas that are lined. D. Select appropriate other types of instruments. E. Remove the glass fibers. F. Move the sensor to the section of the pipe without a sleeve. G. Reinstall the coupling agent. 　　On-site fault phenomenon: The reading increases when the control valve is partially closed or the flow rate is reduced. Analysis of the cause of the on-site failure: The sensor was installed too close downstream of the control valve; when the valve was partially closed, what the flow meter measured was actually the increased flow velocity resulting from the reduced diameter of the control valve, as the flow velocity rises due to the smaller diameter. Correct handling method: Place the sensor away from the control valve, either 30D upstream of the control valve, or move the sensor to 5D upstream of the control valve. 　　Furthermore. When selecting an ultrasonic flowmeter, users should take into full account certain physical and chemical properties of the medium in order to make a proper choice. For more information, please visit the company’s official website at http://www.yb1518.com/. Please keep this link when reproducing the content! http://www.yb1518.com/UploadFiles/2015113102935175.jpg