K-type mass flow meter installation considerations

The excessive mechanical stress of the K-type mass flowmeter during sensor installation can affect the zero point of the mass flowmeter. If these stresses are constantly changing, the meter will experience unacceptable zero-point drift. Therefore, the correct installation of the mass flow meter is an important part of ensuring the normal operation of the equipment.

1, K-type mass flow meter installation position selection

1) The installation location should be far away from sources of interference that can cause mechanical vibration in the pipeline, such as pumps in process lines. If the sensor is used in series on the same pipeline, special effects due to resonance should be placed. The distance between sensors should be at least three times the width of the sensor's overall dimensions.
2) The installation position of the sensor should pay attention to the expansion and contraction of the process pipeline due to temperature changes, especially in the vicinity of the expansion joints of the process pipeline. Because of the expansion and contraction of the pipeline, it will cause transverse stress, which will cause the sensor zero point to change and affect the measurement accuracy.
3) The installation position of the sensor should be far away from the sources of industrial electromagnetic interference, such as high-power generators, transformers, etc. Otherwise, the self-resonance of the measuring tube in the sensor may be disturbed, and the weak signal detected by the speed sensor may be submerged in electromagnetic interference. Noise. The sensor should be at least 5 meters away from the transformer and generator.
4) The installation position of the sensor should ensure that the fluid in the pipeline is always filled with the sensor measuring tube and there is a certain pressure, which requires that the installation position should be at the low end of the pipeline.

2. Selection of K-type mass flowmeter sensor installation method

The installation method of the sensor is mainly determined according to the phase of the fluid and its process conditions. There are three installation methods.
1) If the fluid to be measured is a liquid, the sensor is generally installed with the housing facing downward to prevent the air from accumulating in the vibration tube of the sensor so as to accurately measure the mass flow.
2) If the fluid to be measured is a gas, the sensor is generally installed with the housing facing upward to prevent the condensate from accumulating in the sensor vibrating tube.
3) If the fluid to be measured is a liquid, solid mixture slurry, install the sensor on the vertical official path. This prevents particles from accumulating in the sensor Coriolis force measuring tube. In addition, if the process pipeline needs to be cleaned with gas and steam, this installation method can also facilitate cleaning, but this installation method is more difficult to fix than the previous two, and the pressure loss is greater

3, K-type mass flowmeter installation process other precautions

1) Before installing the sensor on the process line, make sure that the speed sensor coil, the DC resistance of the drive coil, and the resistance value of the platinum resistance thermometer are correct.
2) The sensor mounting flange must be coaxially connected with the pipe flange so as to reduce the installation stress and ensure the measurement accuracy. When installing, it should be ensured that the pipe supports only support the process pipe and the sensor is not allowed to support the process pipe. The sensor housing should be kept free from contact with any objects.
3) When the sensor is installed in the process pipeline, ensure that the piping system and the sensors at the upstream and downstream sides of the sensor are firmly connected at two locations. All threaded connections must be fastened. Clamping the process piping helps to reduce potential vibration disturbances. .
4) Avoid using the sensor housing to move the sensor during installation.
5) Valves or pumps on the process line near the sensor installation position need to have their own support, and cannot support the valve and pump with the support supporting the sensor.
6) Stop valves should be installed upstream and downstream of the sensor.
7) Eliminate installation stress: When installing the sensor, in order to eliminate the installation stress, the most effective method is to first pipe, pre-install the process pipeline and the valve and the sensor as a whole, then lifting, and then welding it with the process master line. In order to make the best effect of stress relief, the sensor, stop valve and process line should be in the same vertical plane.

4, damping

1) When installing the sensor, it is necessary to choose a suitable installation location. In addition to keeping away from the vibration source, in order to eliminate the influence of vibration on the measurement, the way in which the support rod firmly supports the pipeline and the valve is also required during the installation. The lower end of the support rod must be fixed on a stable foundation, and the upper end cooperates with the pipeline clamp to support the process pipeline.
2) After the sensor is installed, its housing should be free to hang.
For the installation methods 1) and 2), the support bar should be symmetrically distributed around the sensor. For the installation method 3), the selection of support points depends on the specific circumstances. If the lower end of the support bar is fixed on the ground, it must be cement and reinforced ground in order to stabilize the support and at the same time play a damping role. The more stable the foundation, the better its shock absorption.