Question About P&ID Format and Understanding

[bzakrajsek]

All-

I am currently working with a Middle Eastern company and we are attempting to match our typical P&IDs to their client's standard.

I am having some trouble understanding the format that they are using and I wondered if anyone recognized this format as a defined standard for P&ID or control.

The client format for P&IDs show interlocks represented by a 5 character number next to a small diamond with an "I" in it. Dependent on what interlocks control a process device (a valve let's say), the P&ID will have the "I" diamond attached to it.

I have included a small sample of their P&ID so as to get a flavor of this style.

Thanks to all in advance. I know this was not extremely descriptive, but I wanted to see what a first response looks like.

Brian

 

[xnuke]

As far as I know, only the Process Industry Practices group has an official standard for P&IDs, but you're not going to see this type of nomenclature in it. ISA publishes the Instrument Symbols and Identification standard 5.1, but the PLC symbol with an "I" in it isn't in accordance with that standard. My guess is it's a software interlock. The small diamond is in the standard, and perhaps represents a hard-wired interlock. I have no guess about the five digit numbers. This looks very client-specific. I hope you have the legend sheets that explain more.

xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[roydm]

It is somewhat similar to P&IDs I have seen
The reference # tells the PLC configurator which interlocks are associated with the solenoid. If you tried to show all the interlocks on the drawing it would be too cluttered and unreadable. It also allows the drawing to be completed before the interlock scheme is finalized.
There will be a spreadsheet of the interlocks by # somewhere.
Roy