The pressure transmitter is suitable for the occasion of measuring the pressure of each medium. Generally, for flammable and explosive occasions, pneumatic and electric pressure transmitters with corresponding explosion-proof grades should be selected. For the measured medium that is easy to be blocked, viscous, corrosive, and low vaporization point, flange pressure transmitters can be selected. Smart transmitters should be selected for high measurement accuracy requirements and harsh environmental conditions
The accuracy of pressure measurement depends to a large extent on the correct installation of the transmitter, the measuring tube and the pressure-taking parts. In some special occasions, the electric pressure transmitter can be directly installed on the process pipeline. It is not necessary to set up a separate bracket. The condition for direct installation on the process pipeline is that the process temperature and ambient temperature should meet the conditions of use of the transmitter
The pressure depends on the source component installed on the horizontal and inclined process pipeline, the position of the pressure point should meet the following requirements:
1. When measuring liquid pressure, the pressure point should be within the range of the angle between the lower half of the process pipeline and the horizontal centerline of the process pipeline from 0°C to 45°C
2. When measuring gas pressure, the pressure point should be in the upper half of the process pipeline
3. When measuring the steam pressure, the pressure point is taken within the range of the upper half and the lower half of the process pipeline and the horizontal center of the process pipeline at an angle of 0 degrees and 45 degrees.
4. The end of the pressure source component should not exceed the inner wall of the process equipment and process piping
5. The installation position of the pressure source component should be selected in the pipe section with a stable flow of the process medium
6. When the pressure source part and the temperature source part are on the same pipeline, the pressure source part should be installed on the upstream side of the temperature source part
7 When measuring the pressure of turbid media with dust solid particles or sediments on the vertical process pipeline, the original parts should be installed obliquely upwards, and the angle with the horizontal line should be greater than 30 ℃, and the horizontal process pipeline should be formed downstream. Acute angle installation.
8. The installation location should have sufficient light, easy to operate and maintain, and should not be installed in a place with vibration, humidity, high temperature, corrosiveness and strong magnetic field interference.
9. When measuring the pressure of a gaseous medium, the transmitter installation position should be higher than the pressure point, when measuring liquid or steam pressure, the transmitter installation position should be lower than the pressure point, the purpose is to reduce additional facilities for exhaust and liquid discharge.
10. The installation location should be as close as possible to the source component. The installation height of the transmitter for measuring low pressure should be the same as the height of the pressure point, especially for measuring liquid media and condensable gas media.
In addition to the installation method of pressure transmitter directly on the process pipeline, it is usually a separate installation method. The column bracket can be made on-site, using U-shaped bolts, or the wall bracket installation method, no matter what kind of installation It should be installed vertically, and the cable entrance of the meter junction box should not face upwards.