Electromagnetic Flowmeter After-Sales Case 3

Field problem

The dispaly of electromagnetic flowmeter is unstable, and customers judge the flow value is high based on past value.

Troubleshooting and analysis

After receiving customer feedback, the technical team of ARTang immediately went to the customer site to check and analyze the faults:

1. the diameter of electromagnetic flowmeter is DN100, which is consistent with the pipe diameter measured on site.

2. Check the sensor coefficient of electromagnetic flowmeter. According to traceability, the sensor coefficient is 1.7534, which is consistent with the factory calibration value before leaving the factory.

3. The flow control valve is installed at the entrance of the electromagnetic flowmeter, and the length of the front and rear straight pipe sections does not meet the installation requirements, resulting in high measurement value.

Solution

1. Replace the installation position of flow control valve.

2. Extend the front and rear straight pipe sections of electromagnetic flowmeter.

Customer feedback

After changing the installation position of the flow adjustment valve and extend the length of the straight pipe section, the flow data becomes normal again said by our customer, and electromagnetic flowmeter is still working well.

Why does the electromagnetic flowmeter avoid being installed behind the valve?

When the medium passes through the valve, there may be two phases. The instability of the dissatisfied pipe and the fluid phase will cause the unstable signal output and affect the measurement accuracy.

Why should the electromagnetic flowmeter avoid being installed in front of the pump?

If the electromagnetic flowmeter is installed in front of the pump, it will generate great negative pressure, and the negative pressure environment will cause the lining damage. If the lining around the electrode is damaged, it will cause pipeline leakage and the flowmeter can't be used normally.