What are P&IDs?
Piping and Instrumentation Diagrams (P&IDs) use a standardized set of symbols, notation and abbreviation to represent the various components of a process. These symbols are designed to be easily recognizable and convey important information about the component they represent. In this guide, we will walk through the basics of P&ID symbols, notation and abbreviation and how to read them.
Important
P&IDs are living documents, and it is important to keep them updated as the process changes over time. Practice is key to understanding P&ID symbols, notation and abbreviation, and interpreting them correctly.
Table of Contents
P&ID symbols can be broadly classified into 7 categories:
Piping Symbols
Examples include pipes, tubes, ducts, multi-line, separators, connectors, end caps, flanges, reducers, and coupling.
Pipe
Jacketed pipe
Thermally insulated pipe
Cooled or heated pipe
Covered gas vent
Curved gas vent
Flange
Butt weld
Reducer
Flexible hose
Steam trap
Viewing glass
Pump Symbols
Pumps are an essential part of the majority of industrial plants that need pumps. These pumps can be used for suction, compression, moving fluid, and also for pressure control. There are many p and id symbols for pumps.
Pump
Vacuum pump or compressor
Centrifugal pump
Gear pump
Screw pump
Screw pump
Vacuum pump
Fan
Axial Fan
Radial Fan
Valve and Control Symbols
Represented by various shapes to indicate the type and function of the control device. Examples include valves, actuators, and controllers.
Pressure reducing valve
Valve
Control valve
Manual valve
Needle valve
Butterfly valve
Ball valve
Globe valve
Diaphragm valve
Vessel Symbols
A vessel is used to store fluids or also be used to alter the characteristics of the fluid during storage. This includes tanks, cylinders, columns, bags.