Electromagnetic Flowmeter Installation Recommendations(Part 2)

6. Installation plus bypass pipe

The pipeline where the flowmeter is installed should have a valve that can cut off the medium in the pipeline to facilitate daily maintenance and maintenance. When the process does not allow flow interruption. A bypass pipe can be added to the pipe where the flowmeter is installed.

7. Install according to the calibration direction

When the flowmeter sensor has a clear flow mark, it should be installed in the calibration direction.

8. Cable entry, cable and conduit

The inlet of the flowmeter, the cable and the threading pipe should be bent downwards and open at the lowest point to prevent water from entering and causing a short circuit.

9. Welding flange

When installing the flowmeter, the flange should be welded first, and then the flowmeter should be installed. It is not possible to weld the flange directly with the flowmeter sensor to avoid the welding slag burning the lining.

10. Distance between converter and sensor

The signal wire between the converter and the sensor cannot be longer than 50m, and the signal wire must be sheathed with galvanized pipe.

11. Grounding measures of the sensor

The flow signal generated by the sensor is very small, only a few millivolts at full scale, so the sensor should be well grounded. The grounding requirements of electromagnetic flowmeters have two aspects:

From the analysis of the working principle of the electromagnetic flowmeter and the loop of the flow induction signal current, the ground terminal of the sensor and the converter must be at the same potential as the measured medium.

Ground, take the earth as zero potential to reduce external interference.

Under normal circumstances, process pipelines are all metal pipes, which are grounded. This requirement is easy to meet. However, in the case of large external electromagnetic field interference, the electromagnetic flowmeter should be equipped with a separate grounding device. The grounding wire should be a multi-strand copper wire with a cross-section greater than 5mm2. The grounding wire of the sensor must not be connected to the common ground wire of the motor or other equipment. To avoid the influence of leakage current. The grounding resistance should be less than 10Ω.

The above information is provided by flow instrument factory.