The issue with numbers in PID
Thread Content
In the PID diagram, what does adding 310/4 to the level L mean? I don’t understand it; please help
Are there any pictures? I don’t quite understand the description.
I don’t understand what it means to add numbers after the L above; could you please explain? Thank you~
This process pipeline and control flow diagram (PID) shown in Figure 310/4 does not use standard codes; in other words, the symbols used in this PID diagram to represent the level gauge are simplified versions. The large ‘L’ denotes the liquid level. Generally, there are other codes following it – for example, LICA refers to a level controller with an indication function. In 310, the ‘3’ represents the section number, while ‘10’ represents the instrument serial number. The notation used in your diagram is not standard. Based on my guess, 310 might be the section number, with ‘1’ and ‘2’ representing the instrument serial numbers.
It’s more or less the same as what was said upstairs. Based on Figure Tank-5/4 and Tank-5/5, it can be inferred that since there is only one circle with no rectangle surrounding it, L is a local level gauge; it might be a magnetic flap level gauge ； In 310, the 3 represents the section number, while 10 represents the instrument serial number; that is, in this section, there are 10 similar local level gauges, with /1 and /2 indicating the first and second ones respectively. This is for reference only; it’s best to find the legend for this PID.
You can first look at the PI&D diagram, the legend for explanations, the numbering specifications, or simply ask the process engineers
The meaning of instrument tag numbers is, simply put, to distinguish between various instruments.
Kai Chuan is truly great – someone takes the time to answer such questions carefully; impressive! ! ! Back then, I really was just a complete novice!