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Electromagnetic flowmeter common error installation instructions

The electromagnetic flowmeter can only obtain accurate measurements when it is full, avoiding the following installation positions:

1. Installation of the highest point of the pipeline (easy to collect bubbles)

2. Install directly in front of the open outlet of a downward line.

3. Be careful not to install a flow tube on the inlet side of the pump to avoid damage to the flow tube lining caused by pumping. A pulsed throttle valve is required when using a reciprocating, diaphragm or plunger pump.

4. When the length of the down pipe exceeds 5m, install a siphon or a bleed valve behind the sensor. To avoid damage to the measuring tube lining caused by low pressure. Ensure full pipe and reduce gas content.

The mounting orientation is usually divided into vertical mounting and horizontal mounting. The most suitable orientation can help avoid gas accumulation and residue accumulation in the measuring tube.

Vertical installation: This orientation is ideal for easy self-draining piping systems and does not require empty tube detection electrodes.

Horizontal mounting: The measuring electrode plane must be level to prevent short-term insulation of the electrodes due to entrained air bubbles. Note: The empty tube detection function works correctly only when the measuring device is horizontally mounted and the transmitter housing is up. If the vibration is very severe, the sensor and transmitter should be installed separately.

Base, support: If the nominal diameter is DN ≥ 350, install the transmitter on a pedestal that can withstand sufficient load. Note that it is not allowed to use the frame to hold the weight of the sensor. This will deform the outer frame and damage the inner field coil. If possible, it is best to install components such as valves, tees, elbows, etc.

Ensure the following required inlet and outlet straight sections to ensure measurement accuracy: inlet length > 10 × DN outlet length > 5 × DN sensor and transmitter grounding sensor in the center of the pipeline

Grounding: The sensor and the medium must have the same potential to ensure measurement accuracy and avoid corrosion damage of the electrode. The equipotential is ensured by the ground reference electrode mounted in the sensor. If the media flows in an unlined, grounded metal tube, it can be grounded by connecting to the transmitter housing. The grounding for the separate ground is the same as above.

Note: If you are not sure if the media is properly grounded or not, install a grounding ring.

[Electromagnetic flowmeter other installation precautions]

(1) Straight pipe length requirements

In order to obtain normal measurement accuracy, the electromagnetic flow sensor must also have a length of straight pipe upstream, but its length is lower than most other flow meters. 90o elbows, T-tubes, concentric reducers, and fully open gate valves are generally considered to be only 5 times the diameter (5D) length of the straight pipe section from the center line of the electrode (not the sensor inlet end connection surface). Valves with different opening degrees are required. 10D; the downstream straight pipe section is (2~3)D.

(2) Installation of negative pressure piping

Fluoroplastic lining sensors shall be used with caution in negative pressure piping; positive pressure piping shall be protected against negative pressure, such as piping with liquid temperatures above room temperature, and fluid cooling shrinkage may form negative after the sensor shuts off the upstream and downstream shut-off valves. Pressure, should be installed near the sensor negative pressure prevention valve

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