P&ID is a very common term used in the world of process industries. Working as a Process Engineer in a manufacturing plant I could not avoid myself from creating new and/or modifying the already existing P&ID to the as-is plant modifications. All the Chemical Engineering and related Engineering students have also learned about it or at least heard. As we all (most of us) know P&ID is Piping and Instrumentation Drawing.
A P&ID is a detailed graphical representation of a process including the hardware and software (e.g., piping, equipment, instrumentation) necessary to design, construct and operate the facility. As defined in the PIC001: Piping and Instrumentation Diagram Documentation Criteria by Process Industry Practice (PIP) – a consortium of process industry owners and engineering construction contractors who serve the industry.
Like most of the industries in USA; the process plant that I earlier worked for also used the PIP’s criteria for P&ID. The document created by them is very precise and hence very helpful for new guys in the industry. PIP also provides a detail list of all the standard set of symbols and instruments that should be used.
P&ID diagram has to show the interconnection of all the process equipments and the instruments used. It is critical to show the actual sequence of equipment and other assets of the process, as well as how they are connect. During the design stage, the diagram also provides the basis for the development of process. P&IDs play a very significant role in the maintenance and modification of the process.
P&ID is a graphical (symbolic) representation of the process which demonstrates all the piping with flow direction and instruments details with their controls. The equipments also show all the operational information at the top or bottom of the sheet hence avoids cluttering. All the equipments and instruments including pipelines and values are tagged uniquely.
There are various software programs available today to create these P&ID fast and intelligent. I have been fortunate enough to be working on creating the AutoCAD P&ID package, which is very easy to use, save a lot of time in drawing and editing, creates it’s own database and save all the properties for the assets. More information could be found at http://usa.autodesk.com/adsk/servlet/index?id=8877989&siteID=123112