Piping and instrumentation diagram

A piping and instrumentation diagram (P&ID) is a detailed diagram in the process industry which shows the piping and process equipment together with the instrumentation and control devices. A piping and instrumentation diagram (P&ID) is a detailed diagram in the process industry which shows the piping and process equipment together with the instrumentation and control devices. Superordinate to the piping and instrumentation diagram is the process flow diagram (PFD) which indicates the more general flow of plant processes and the relationship between major equipment of a plant facility.