P&ID Tag Numbering System Explained: Tags, Loops and Examples
A P&ID tag numbering system is the identification language that connects a symbol on a Piping and Instrumentation Diagram to the real equipment, instrument, valve, pipeline, database record and maintenance history. Instrument tags commonly combine function letters such as FIC with a loop number such as 101 . Equipment, manual valves and pipelines usually follow separate project conventions. Decode the letters using the declared standard, decode numbers using the project philosophy, and verify every interpretation against the drawing legend and controlled registers. Fast answer: In FIC-101 , F identifies flow as the measured variable, while I and C describe indication and control. 101 identifies the loop under the project convention. Related devices may include FT-101 , FIC-101 and FV-101 . Standards do not force every plant to use identical area digits, separators, number blocks or suffixes. Contents Definition Standards Instrument anatomy Letter codes Loop numbering Equipment ...