P&ID Symbols Legend

P&ID Symbols Legend

Like other specialized diagrams, P&IDs are comprised of standard shapes and symbols. There's a huge variety of symbols, depending on industry and manufacturer, so we've created a guide to the most popular P&ID symbols.

To experiment with these symbols, just click the buttons below. With Lucidchart's P&ID software, building a piping and instrumentation diagram is fast, easy, and completely free.

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Common P&ID Symbols Legend

Piping and instrumentation diagrams, or P&IDs, are used to create important documentation for process industry facilities. The shapes in this legend are representative of the functional relationship between piping, instrumentation, and system equipment units. We've broken them down into seven main groups: equipment, piping, vessels, heat exchangers, pumps, instruments, and valves.

With Lucidchart, it's easy to access all of the featured P&ID symbols. Users can also import .SVGs and other image files to create a custom P&ID library for any situation.


EQUIPMENT

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, vaccuums, and other mechanical devices.

P&ID equipment legend

PIPING

A pipe is a tube that transports fluid substances. Piping can be made of various materials, including metal and plastic. The piping group is made up of one-to-many pipes, multi-line pipes, separators, and other types of piping devices.

P&ID equipment legend

VESSELS

A vessel is a container that is used to store fluid. It may also alter the characteristics of the fluid during storage. The vessels category includes tanks, cylinders, columns, bags, and other vessels.

P&ID equipment legend

HEAT EXCHANGERS

A heat exchanger is a device that's designed to efficiently transfer heat from different areas or mediums. This category includes boilers, condensers, and other heat exchangers.

P&ID equipment legend

PUMPS

A pump is a device that uses suction or pressure to raise, compress, or move fluids in and out of other objects. This section is comprised of both pumps and fans.

P&ID equipment legend

INSTRUMENTS

An instrument is a device that measures—and sometimes controls—quantities such as flow, temperature, angle, or pressure. The instruments group houses indicators, transmitters, recordings, controllers, and elements.

P&ID equipment legend

VALVES

A valve regulates, directs, or controls the flow of a fluid by opening, closing, or partially obstructing passageways in a piping system.This category includes rotameters, orifices, and other types of valves.

P&ID equipment legend

Lucidchart offers every P&ID shape that engineers need. Easily create piping and instrumentation diagrams and collaborate among your team members with Lucidchart's P&ID tutorial.

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