Electromagnetic Flowmeter Installation Requirements

Electromagnetic flowmeter installation environment requirements

The installation environment of the electromagnetic flowmeter directly affects its measurement accuracy and service life. First of all, extreme temperature environments should be avoided, and the ideal working environment temperature should be between 5°C~55°C. If it must be installed in a place with severe temperature changes or high temperature radiation, thermal insulation and ventilation measures must be taken. For outdoor installations, special attention should be paid to protection from rain, moisture and sun to avoid rain, water immersion and direct sunlight, which may cause moisture in the internal circuitry of the meter or aging of the housing material.

The installation location should be selected in a dry and ventilated place to avoid corrosive gas environments. If this is unavoidable, additional ventilation facilities are required. At the same time, the electromagnetic flowmeter is extremely sensitive to electromagnetic interference, and must be kept away from strong magnetic field sources, such as large motors, transformers and other equipment, and the distance should be at least 3-5 meters. Vibration is also an important factor affecting the accuracy of the electromagnetic flowmeter, the installation site should be as free as possible without strong vibration, if the pipeline vibration is large, it is necessary to add pipeline fixed support on both sides of the flowmeter or use shock absorption devices.

In addition, the choice of installation location should also consider ease of maintenance, ensuring that there is sufficient operating space around the instrument for routine inspection, calibration, and repair. For explosion-proof electromagnetic flowmeters, they must be moved to a safe area for operation during maintenance, which should be planned in advance when installing and positioning.

Requirements for the location and orientation of the pipeline

The position of the electromagnetic flowmeter in the pipe has a decisive influence on its measurement accuracy. The first principle is to ensure that the pipe is fully measured, i.e. the medium must be completely filled with the pipe at the measuring position. It is strictly forbidden to install at the highest point of the pipe or above the downward drain pipe, as these locations are prone to gas accumulation and lead to measurement errors. When the medium is not in the pipe, you can take the method of raising the back end of the flowmeter to make it full, or choose to install the pipe at a low point (but pay attention to the possible sediment problems, you need to set up a vent).

Regarding installation direction, electromagnetic flow meters can be installed either horizontally or vertically, but each has specific requirements. When installed horizontally, it is crucial to ensure that the measuring electrode axis is in a horizontal position to prevent air bubbles in the fluid from accumulating at the top of the pipe, which can lead to temporary insulation between the electrodes. Additionally, the horizontally installed pipeline can be slightly inclined (approximately 1-5°) to facilitate the removal of gas impurities from the pipeline. When installed vertically, it is preferable for the fluid flow direction to be bottom-up, ensuring that the pipe remains filled with liquid at all times, which is especially suitable for liquid-solid two-phase fluids and promotes uniform wear of the sensor lining, extending its service life.

In choosing the specific location within the piping system, the electromagnetic flowmeter should be installed at the rear end of the pump, and it is strictly prohibited to install it on the suction side, because the negative pressure at the pump inlet may cause the lining of the measuring tube to shift or be damaged. The valve should be installed on the downstream side of the flowmeter, and the control valve and shut-off valve must be positioned downstream of the sensor, not upstream. For systems using diaphragm or peristaltic pumps, it is recommended to install pulsation dampeners at the pump outlet to mitigate the negative pressure effects during suction at the pump inlet.

Electrical installation requirements

The electrical installation of an electromagnetic flowmeter directly affects signal quality and measurement stability. A proper grounding system is a crucial prerequisite for ensuring measurement accuracy. The electromagnetic flowmeter housing, the fluid being measured, and the pipe connection flange should all be connected to the same potential and grounded reliably. This is because the working principle of electromagnetic flowmeters is based on electromagnetic induction, which generates very weak induced signals (usually in the millivolt range), and good grounding can eliminate interference from external parasitic potentials.

In terms of power connection, it should be ensured that the voltage is stable and meets the specifications of the flowmeter. If conditions permit, the electromagnetic flowmeter should be equipped with an independent power supply to avoid voltage fluctuations and interference caused by sharing power with other high-power equipment. For installation in hazardous areas, the corresponding explosion-proof electrical installation specifications must also be strictly observed.

Post-installation inspection and verification

Electrical inspections include verifying that the power supply is properly wired, the voltage meets the requirements, the ground resistance is up to standard, and the signal wires are securely connected and the shield is intact. After powering on, observe whether the instrument display is normal, whether there is any abnormal alarm or indication, and whether the operation of each function button responds normally.

Zero-point calibration is a necessary step after installation. It should be carried out under conditions where the pipeline is filled with a stationary medium (usually water) to eliminate static errors. For high-precision applications, on-site flow calibration is also required to validate measurement accuracy by comparing the actual flow rate with the reading on the instrument. Calibration can be performed using portable ultrasonic flowmeters, volumetric methods, or weighing methods, depending on the site conditions.