Electromagnetic flowmeter before and after the need to install expansion joints

Expansion joints need to be installed before and after the electromagnetic flowmeter to adapt to the thermal expansion and contraction of the pipeline and to protect the sensor from external interference such as pipeline vibration.

1. Overview of electromagnetic flowmeter

Electromagnetic flowmeter is an instrument used to measure the flow of fluid in conductive media. It can not only measure the flow of liquids such as electrolytes and corrosive liquids, but also the flow of conductive media such as chemicals and sewage. The electromagnetic flowmeter uses the Faraday electromagnetic induction principle to calculate the flow rate of the fluid through the voltage signal generated by the electromagnetic induction of the conductor in the fluid by the probe, thereby achieving measurement and control of the fluid.

2. The role of expansion joints installed before and after the electromagnetic flowmeter

1. Adapt to the thermal expansion and contraction of the pipeline

Electromagnetic flowmeters are generally installed on the pipeline, and As the temperature of the pipe changes, the length of the pipe will change, which may cause problems in the connection between the electromagnetic flowmeter and the pipe. If there is no expansion joint, stress will be generated when the pipeline becomes longer, which will cause pressure on the electromagnetic flowmeter probe, affect the measurement accuracy and even damage the electromagnetic flowmeter. Therefore, in order to adapt to the thermal expansion and contraction of the pipeline, installing expansion joints can effectively avoid this situation.

2. Protect the sensor from external interference

The sensor of the electromagnetic flowmeter is relatively sensitive to external interference, such as pipeline vibration, which will affect the measurement of the electromagnetic flowmeter. If there is no expansion joint, the vibration of the pipeline will be directly transmitted to the electromagnetic flowmeter, causing measurement errors or even damaging the electromagnetic flowmeter. The installation of expansion joints can play a buffering and shock-absorbing role and protect the electromagnetic flowmeter from external interference such as pipeline vibration.

3. Types and selection of expansion joints

1. Types of expansion joints

There are many types of expansion joints, including pressure-compensated expansion joints and metal corrugated expansion joints. Mainly tubular expansion joints. Pressure-compensated expansion joints use different deformations of elastic materials to compensate for the elongation or shortening of pipelines, and can be applied to the installation of most pipelines. Metal bellows type expansion joints compensate for the expansion and contraction of the pipe through the expansion and contraction of the metal bellows, and are suitable for some special pipes.

2. Selection of expansion joints

The selection of expansion joints should be determined based on factors such as the usage of the pipeline, pipe diameter, and working pressure. When selecting an expansion joint model, it is generally necessary to consider factors such as the expansion and contraction of the pipe, operating temperature, operating pressure, liquid medium, etc.

IV. Summary

In short, expansion joints need to be installed before and after the electromagnetic flowmeter to adapt to the thermal expansion and contraction of the pipeline and to protect the sensor from external interference such as pipeline vibration. When installing expansion joints, it is necessary to select the appropriate model and perform correct construction and installation according to the actual situation.