Jiangsu Jinhu Dongxiang Instrument
Co., Ltd. is a professional manufacturer mainly producing pressure transmitters
, ultrasonic flow meters
and other products. Products mainly include liquid level transmitters
, flange type liquid level transmitters
, double flange liquid level transmitters
, integrated digital temperature transmitters
and other instruments. Regarding the causes and solutions of ultrasonic flowmeter
failures, we introduce the following points:
1.Symptoms: Abnormal flow rate display, dramatic changes in data
Cause analysis: The sensor is installed in a place with a large vibration in the pipeline or the flow device is changed (such as the downstream of a regulating valve, a pump, a reduction orifice)
Solution: Install the sensor away from the vibration source or move it upstream of the fluid change device
2.Symptom: Incorrect reading
Reason analysis: A. The sensor installed on the top and bottom of the horizontal pipe interferes with the ultrasonic signal. B. The sensor is installed on the pipe where the water flows downward, and the pipe is not full of fluid.
Solution: A. Mount the sensor on both sides of the pipe B. Mount the sensor on a fluid-filled pipe section
3.Symptom: Incorrect reading
Analysis of reasons: A. Devices that cause strong fluctuations in the flow state, such as: venturi, orifice plate, vortex street, turbine or partially closed valve, are within the range transmitted and received by the sensor, making the reading inaccurate. B. The input diameter of the flowmeter does not match the inside diameter of the pipeline.
Solution: A. Install the sensor away from the above device, the sensor upstream from the device 30D, downstream from the device 10D or move upstream of the device. B. Modify the pipe diameter to match
4. Symptom: The sensor is good, but the flow rate is low or no flow rate
Cause analysis: A. The paint and rust outside the pipeline have not been removed. B. The pipe surface is uneven or installed at the welding seam. C. The roundness of the pipe is not good, the inner surface is not smooth, and there is pipe-lining fouling. This may happen if the pipe is cast iron. D. The measured medium is too low for pure or solid suspended matter. E. The sensor is installed on the fiberglass pipe. F. The sensor is mounted on the casing, which weakens the ultrasonic signal. G. The sensor is not well coupled to the pipeline, and there are gaps or bubbles in the coupling surface.
Solution: A. Clear the pipeline again and install the sensor. B. Grind the pipe flat or away from the weld. C. Select the place where the inner surface of the pipe, such as steel pipe, is smooth. D. Use other suitable types of instruments. E. Remove the glass fibers. F. Move the sensor to the unpiped pipe section. G. Reinstall the couplant.
5.Failure phenomenon: When the control valve is partially closed or the flow is reduced, the reading will increase.
Reason analysis: The sensor is installed too close to the downstream of the control valve. When the valve is partially closed, the flowmeter actually measures the flow rate of the control valve to reduce the diameter and increase the flow rate. The flow rate increases due to the reduction of the diameter.
Solution: Move the sensor away from the control valve, 30D upstream of the sensor or 5D upstream of the control valve.