The main problems are: 1 indicates long-term inaccuracy; 2 indicates no indication at all; 3 indicates large-scale fluctuations, unable to read; 4 indicates no return to zero; 5 indicates no flow when there is small flow; When the flow rate changes, the indication change cannot keep up; 8 meter K coefficient cannot be determined, and multiple pieces of data are inconsistent. Analysis and solution Summarizing the main causes of these problems, mainly related to the following aspects: 1. Problems with selection. Some vortex sensors are selected on the caliber selection or after the design and selection, because the process conditions are changed, so that the selection is larger, the actual selection should be as small as possible to improve the measurement accuracy. The reason for this is mainly the same. Questions 1, 3, and 6 are related. For example, a vortex pipeline is designed for use by several equipment. Because some of the equipment is not used sometimes, the actual actual flow is reduced. The actual design results in too large an original design, which is equivalent to an increase in measurable flow. The lower limit, when the process pipe is small, the indication is not guaranteed. When the flow is large, it can be used, because it is sometimes too difficult to rebuild. Changes in process conditions are only temporary. The re-tuning of the parameters can be combined to improve the indication accuracy. 2. Installation problems. The main reason is that the length of the straight pipe in front of the sensor is not enough, which affects the measurement accuracy. The reason for this is mainly related to the problem 1. For example, the straight pipe section in front of the sensor is obviously insufficient. Since the FIC203 is not used for metering, it is only used for control, so the current accuracy can be used equivalent to the downgrade. 3. Reasons for parameter setting direction. The instrument is incorrectly indicated due to a parameter error. The parameter error makes the secondary instrument full-scale frequency calculation error, and the reason for this is mainly related to questions 1, 3. The full-scale frequency is similar, which indicates that the long-term inaccuracy is indicated. The full-scale frequency of the actual full-scale frequency and large-dry calculation indicates that the range is fluctuating and cannot be read. The inconsistency of the parameters on the data affects the final determination of the parameters, and finally passes. Recalibration combined with mutual comparison to determine the parameters solves this problem. 4. The secondary instrument is faulty. There are many faults in this part, including: when the instrument board is disconnected, the range setting has individual bit display bad, and the K coefficient setting has individual bit display bad, which makes it impossible to determine the range setting and K factor setting. Part of the reason is mainly related to questions 1, 2. The problem is solved by fixing the corresponding fault. 5, four-way line connection problem. On the surface of some circuits, the line connection is very good. Careful inspection, some connectors are actually loose and the circuit is interrupted. Some connectors are tightly connected, but the fastening screws are fastened to the wire sheath due to the secondary line problem, which also makes the circuit Interruption, this part of the reason is mainly related to question 2. 6. The connection problem between the secondary instrument and the subsequent instrument. Due to the problem of the subsequent instrument or the maintenance of the subsequent instrument, the mA output circuit of the secondary instrument is interrupted. For this type of secondary instrument, this part of the reason is mainly related to the problem 2. Especially for the subsequent recorders, in the case that the recorder cannot be repaired for a long time, it is necessary to pay attention to shorting the output of the secondary meter. 7. The circuit always has no indication due to the failure of the secondary instrument flat-axle cable. Due to long-term operation, coupled with the influence of dust, the flat-axle cable is faulty, and the problem can be solved by cleaning or replacing the flat-axis wire. 8. For the problem 7, the main problem is that the secondary instrument shows that the fixing screw of the meter head is loose, causing the head to sink, the pointer and the case friction are large, and the movement is not working. By adjusting the meter head and re-fixing, the problem is solved accordingly. 10. Due to poor on-site adjustment, or due to actual changes after the adjustment. Due to the on-site vibration and noise balance adjustment and sensitivity adjustment is not good. Or because of the change of the situation after a period of operation after the adjustment, causing the indication problem, this part of the reason is mainly related to questions 4 and 5. Use an oscilloscope, plus the combined process operation, and re-adjust. Vortex flowmeter installation requirements for straight pipe sections: Properly selecting the installation point and properly installing the flowmeter are very important links. If the installation link is wrong, the measurement accuracy will be affected, and the heavy one will affect the service life of the flowmeter and even damage the flowmeter. It is very important that the vortex flowmeter installation meets the requirements for straight pipe sections. Its detailed requirements are as follows: The flowmeter has certain requirements on the upstream and downstream straight pipe sections at the installation point, otherwise the measurement accuracy will be affected. If there is a diverging pipe upstream of the installation point of the flowmeter, the upstream of the flowmeter shall have a straight pipe section of not less than 18D (D is the pipe diameter), and the downstream shall have a straight pipe section of not less than 5D. If there is a 90° elbow or a downward joint upstream of the installation point of the flowmeter, there should be a straight pipe section of not less than 20D upstream of the flowmeter, and a straight pipe section of not less than 5D downstream. If there is a 90° elbow on the same plane upstream of the installation point of the flowmeter, there should be a straight pipe section of not less than 25D upstream of the flowmeter, and a straight pipe section of not less than 5D downstream. The flow regulating valve or pressure regulating valve should be installed as far as possible downstream of the flowmeter 5D. If it must be installed upstream of the flowmeter, the upstream of the flowmeter should have a straight pipe section of not less than 25D, and the downstream should have a straight pipe section of not less than 5D. . If there is a piston type or plunger type pump in the upstream of the flowmeter, a piston type or a Roots type fan and a compressor, there should be a straight pipe section of not less than 25D upstream of the flowmeter, and a straight pipe section of not less than 5D in the downstream. Concerned about surprises Label: Vortex flowmeter main problem and its solution Previous: Differential Pressure Transmitter Troubleshooting Next: How to troubleshoot the dryer Best Kitchen Gadgets,New Kitchen Gadgets,Chef Tools,Kitchen Utilities Garwin Enterprise Co.,Ltd , https://www.garwincn.com
9. Use environmental issues. In particular, the sensor part installed in the well is affected by the humidity of the environment, which causes the circuit board to be damp. This part is mainly related to questions 2 and 2. Through the corresponding technical improvement measures, the sensor part with large humidity is re-disposed to separate the probe part and the conversion part, and the separate type sensor is used. Therefore, the working environment is good, and this part of the instrument has been running well.
If there is a tapered tube upstream of the installation point of the flowmeter, there should be a straight pipe section of not less than 15D (D is the pipe diameter) upstream of the flowmeter, and a straight pipe section of not less than 5D in the downstream.
Special attention: If the valve is installed near the upstream of the installation point of the vortex flowmeter, the valve is continuously opened and closed, which has a great influence on the service life of the flowmeter, and it is very easy to cause permanent damage to the flowmeter. The flowmeter should be avoided to be installed on the very long pipelines in the overhead. After a long time, the flowmeter can easily leak the seal of the flowmeter due to the drooping of the flowmeter. If it has to be installed, it must be in the upstream and downstream of the flowmeter. Pipe fastening devices are provided separately. 