I’m asking how to identify various level gauges and pressure gauges on the P&ID

DISP is an abbreviation for DISPLAY; why is it included in the level gauge? How can various level gauges/pressure gauges be identified in a PID controller? Help needed

DISP should be the gauge beside the tank； The remote level gauges shown in your diagram are all double-flange differential pressure level gauges ； Also: What was said upstairs is correct; there’s a legend at the beginning of the drawings, so it’s better to rely on that legend.

Usually, the instrument type is not indicated; based on these screenshots of yours, only the differential pressure values are shown – this seems to be the practice of this patent holder, and it looks like it’s from UOP’s products

Impressive, this is a SNEC bag

This post was last edited by ZhiGE on 2020-8-22 at 10:25. 1. DISP=DISPLACER refers to a float level transmitter. Some level transmitters are also labeled D/P, indicating that they are level transmitters that operate on the principle of differential pressure. The two are easily confused. 2. There are many types of level and flow meters; in the P&ID, it is necessary to know which type they belong to, and this can be found in the legend at the beginning of the P&ID. 3. Level gauges and pressure gauges are local indication instruments ； Level transmitters and pressure transmitters are considered \"remote sensing instruments\", with 4–20mA signals sent to the control system for display or control purposes. 4. At present, most of the process packages in the chemical industry are imported, as are some of the instruments. Due to reasons related to design institute databases and existing practices, English is still used for labeling on most P&IDs. It is hoped that as more projects are carried out, design institutes will gradually switch to using Chinese labels, thereby making it easier for technical and operational personnel to read and understand them.