Instrument pressure tapping issue
Thread Content
A differential pressure transmitter is used to measure the liquid level in high-pressure containers; the design team added a connecting pipe between the positive and negative pressure pipes. What is the purpose of this connecting pipe?
No PID diagram or physical diagram?
Voltage equalization function, used for instrument maintenance and calibration.
If it is for use when calibrating a meter, how is it used? You can take a look at the circled area in the attachment
Equalizing voltage – what nonsense. . . It’s adding extra details that aren’t necessary. . . Who drew this picture? Go and cut off his dog’s paws, roast them, and offer them as an offering for the Year of the Dog. . . . . . .
What’s the use of this? Waiting for experts to provide an answer. . .
The specific function is unknown; such an installation method is not listed in the HG standard installation manual. It might have been added due to special properties of the medium or other on-site factors. It is recommended to consult the design institute.
What is 5? There are legend annotations, right? I guess it’s the liquid in the condensate negative pressure tube that prevents any impact on subsequent differential pressure measurements; by ensuring that the negative pressure tube is filled with a gas phase, there is no need for a negative offset in the differential pressure transmitter settings. Otherwise, the negative pressure tube would have to be filled with isolating fluid or oil, or a dual-flange differential pressure transmitter would have to be used.
Is the P below the instrument tee used to connect certain special process pipelines, such as the waste discharge system or systems for handling specific types of media? Is it related to the evacuation of the pipelines when removing the instrument? Analysis is required in conjunction with this.
In the diagram, 5 represents a pipe clamp for a straight-through connection. The medium is diesel at 9.3 MPA and 320 degrees; due to the high H2S levels, connections are made in close proximity below the instrument tee.