Instrument Symbol


Thread Starter


I have received a P&ID about biogas treatment and I found a symbol which is strange to me. The symbol consists of two circles with a line between and its designation is P2091.

Does anyone recognize this symbol?

email: [email protected]
Is there a source for obtaining instrument symbols, preferably in
AutoCad or DXF or shapefile format??

It would have been nice if a bit more information was given such as how and what it was connected to reduce the speculation. If this truly a instrument symbol, it appears to be a pressure instrument. People sometimes use the double circle to represent an enclosure such as an O'Brien box or to represent steam or electrical tracing.

William (Bill) L. Mostia, Jr. PE
Sr. Consultant
SIS-Tech Solutions


>If its not there, its not standard

Thank you all.

Yes, it is not an standard symbol. Today, I received an email from the person who has sketched the P&ID and he had mentioned that the symbol represents centrifugal pump!!!!

Unfortunately, some people don't still care about any common standard and only follow their own standard.