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Electromagnetic flowmeter installation is worthy of caution

Electromagnetic flowmeters are widely used in petroleum, chemical, metallurgy, textile, food, pharmaceutical, paper and other industries. The principle of electromagnetic flowmeter measurement is Faraday's law of electromagnetic induction. The main components of the sensor are: measuring tube, electrode, excitation coil, iron core and yoke housing. HD-LDE electromagnetic flowmeter electromagnetic flowmeter installation is worthy of warning about what matters, the following is for you to answer.

First, we must pay attention to the choice of installation form

1. Integral type: The sensing part and the conversion part of the flow meter are integrated into one body, and the advantage is that it is easy to install.

2. Separate type: Install the sensing part of the flowmeter on the pipe to be tested, and install the conversion part in a room that is easy to operate. Applicable to occasions with poor on-site environment (but the separation length should be less than 30m).

Second, we must pay attention to the choice of grounding ring

If the pipe connecting the meter is insulated relative to the medium being tested, you need to use a grounding ring.

Third, we must pay attention to the choice of ball valve

For the process where the fluid flow in the pipeline must not be stopped, and the medium is required to not overflow, a ball valve is required. However, if the flow is allowed to be interrupted when the flowmeter is installed or disassembled (or the assembly and disassembly operation does not affect the work of the pipeline), the electromagnetic flowmeter is directly mounted on the short flange of the flange without adding a ball valve.

Fourth, we must pay attention to the attention points of the installation

1. The electrode axis must remain approximately horizontal.

2. Ensure that the measuring tube must be filled at all times.

3. Make sure there is enough space for bolts and nuts to be installed near the pipe flange.

4. Pipeline support should be provided in the pipe section where the flowmeter is installed to reduce the vibration of the pipeline operation.

5. Strong electromagnetic fields should be avoided near the flowmeter.

6. For long pipelines, control valves and shut-off valves should be installed downstream of the flowmeter.

7. In the case of "open feed or discharge", the instrument should be installed in the lower section of the pipe.

8. Based on the electrode axis, the inlet straight pipe section should be greater than or equal to 5 times the measuring tube diameter, and the outlet pipe should be greater than or equal to 2 times the measuring tube diameter.

Fifth, we must pay attention to the grounding of the electromagnetic flowmeter

The sensor should have a good separate grounding wire (copper core section ≥16mm2), and its grounding resistance is <10 ohms; if the pipe connecting the sensor is coated with an insulating layer or a non-metallic pipe, a grounding ring (grounding wire) should be provided on both sides of the sensor. Copper core section ≥16mm2).

Sixth, we must pay attention to the cable and electrical connection

Separate connecting cables (signal transmission and excitation) are as short as possible from the perspective of reducing interference and saving money. Generally, the limitations of the dielectric conductivity, the cross section of the excitation cable, and the type (core, layer, and shield) of the signal cable must be considered.

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