Function and purpose of P&IDs P&IDS are foundational to the maintenance and modification of the process that it graphically represents. At the design stage, the diagram also provides the basis for the development of system control schemes, like (HAZOP). For processing facilities, it’s a graphic representation of • Key piping and instrument details • Control and shutdown schemes • Safety and regulatory requirements • Basic start up and operational information When to use P&IDs and who uses them P&IDs are a schematic illustration of the functional relationship of piping, instrumentation and system equipment components used in the field of instrumentation and control. They are typically created by engineers who are designing a manufacturing process for a physical plant. 
These facilities usually require complex chemical or mechanical steps that are mapped out with P&IDs to construct a plant and also to maintain plant safety as a reference for Process Safety Information (PSI) in Process Safety Management (PSM).
Use the power of AutoCAD P&ID and extend its capabilities to suit your needs. For example, if a line is connected (e.g. Related) to a pump and the pump. Here are some examples of P&ID symbols. You can review a full overview of all P&ID symbols included in Lucidchart if needed. Equipment is comprised of miscellaneous P&ID units that don't fit into the other categories. This group includes hardware like compressors, conveyors, motors, turbines, vacuums, and other mechanical devices.
If something does go wrong, reviewing the P&ID is usually a good place to start. P&IDs are invaluable documents to keep on hand, whether they’re used to streamline an existing process, replace a piece of equipment, or guide the design and implementation of a new facility. With the record they provide, changes can be planned safely and effectively using Management of Change (MOC). P&IDs are used by field techs, engineers, and operators to better understand the process and how the instrumentation is interconnected. They can also be useful in training workers and contractors. What are P&IDs all about? P&IDs play an essential role in the process engineering world to show interconnectivity, but they don’t necessarily include specifications.
Specifications are usually provided in separate documents. If you use software to create your P&IDs, there are some basic steps to follow: • Create and check an equipment list. Use the symbols within the library after you’re sure of your list.
• Connect pipes and equipment, then review the details with a trusted colleague. Walk through the process several times and search for inefficiencies. • Share with collaborators.