Learn smart differential pressure transmitter installation and notes

Installation of differential pressure transmitter

1. The installation position of the differential pressure transmitter on the process pipeline is related to the measured medium. In order to obtain a better installation effect, the following conditions should be considered:

①Prevent direct contact between the transmitter and the corrosive or overheated measured medium;

②Prevent the dross from depositing and blocking in the impulse pipe;

③ The lengths of the pressure pipes on both sides of the positive and negative pressures should be the same as possible;

④ The liquid column pressure head in the pressure-inducing pipes on both sides of the positive and negative pressures should be balanced;

⑤The pressure pipe is installed in the place with the smallest temperature gradient and temperature fluctuation.

2. When measuring the liquid flow, the differential pressure transmitter should be installed next to or below the pipe under test so that air bubbles can be discharged into the pipe;

3. When measuring gas flow, the differential pressure transmitter should be installed beside or above the pipeline to be measured, so that the accumulated liquid can easily flow into the pipeline;

4. When measuring the steam flow, the differential pressure transmitter should be installed under the pipe under test so that the condensed water can be filled in the pressure pipe.

Special attention should be paid to prevent the temperature of the differential pressure transmitter from contacting the medium when measuring steam or other high-temperature media to exceed the limit temperature of the transmitter.

Smart differential pressure transmitter precautions for daily use

1. Do not apply a voltage higher than 36V to the transmitter, which will cause damage to the transmitter;

2. Do not touch the diaphragm with hard objects, resulting in damage to the isolation diaphragm;

3. The measured medium is not allowed to freeze, otherwise the sensor element isolation diaphragm will be damaged, resulting in damage to the transmitter. If necessary, the temperature of the transmitter should be protected to prevent freezing;

4. When measuring steam or other high-temperature media, the temperature should not exceed the limit temperature when the transmitter is used, and a heat sink must be used when the temperature is higher than the limit temperature of the transmitter;

5. When measuring steam or other high-temperature media, a cooling pipe should be used to connect the transmitter and the pipeline, and use the pressure on the pipeline to transmit it to the transformer. When the measured medium is water vapor, an appropriate amount of water should be injected into the heat pipe to prevent the superheated steam from directly contacting the transmitter and damaging the sensor;

6. In the process of pressure transmission, the following points should be paid attention to:

① Do not leak air at the connection between the transmitter and the heat pipe;

② Before starting to use, if the valve is closed, the valve should be opened very carefully and slowly during use, so as to avoid the measured medium directly impacting the sensor diaphragm, thereby damaging the sensor diaphragm;

③The pipeline must be kept unobstructed, the sediment in the pipeline will pop out and damage the sensor diaphragm.

What to do if positive and negative pressures of the differential pressure transmitter are reversed?

Sometimes if you are not careful at work, it will cause the high and low pressure conduits of the transmitter to be reversed. Can the transmitter work normally in this case? Does the pressure guiding pipe need to be removed and then re-laid? Can the 3051 transmitter work normally if the positive and negative pressure connections are reversed?

If the 3051 transmitter is used to measure the static pressure liquid level, the pressure guiding tube is reversed, and it can only be said that the normal operation is violated, and the output is displayed in reverse. If the liquid level is at the lowest position. The output of the 3051 transmitter is not zero, but 100%. If the liquid level is at the highest position, the output of the 3051 transmitter is not the maximum, but zero percent. This is only for liquid level measurement. If it is a 3051 differential pressure transmitter that measures flow, the 3051 differential pressure transmitter pressure pipe is reversed, and it basically cannot work.

The 3051 transmitter pressure pipe is reversed, do I need to remove it and re-lay it?

If the installation position of the 3051 transmitter is easy to operate, it can be removed and re-laid. If the installation position is inconvenient and dangerous, then the forward and reverse conversion modules inside the 3051 transmitter can be changed. The intelligent 3051 transmitter can use the HART protocol 375 hand communicator configuration to realize the change of the forward and reverse conversion modules inside the transmitter. As long as it is set to reverse in the configuration, the pressure guiding pipe can be laid. Reverse problem.

3051 transmitter, its positive direction means that the differential pressure signal of the transmitter increases and the output also increases. Its reverse means that the differential pressure signal of the transmitter increases and the output also decreases. For any transmitter with forward and reverse conversion, when the pressure guiding pipe is laid in reverse, as long as it is set to the reverse output state, the transmitter can work according to the normal output, so there is no need to change the pressure guiding pipe.