Reading P&ID Symbols: A Step-by-Step Guide – GetReskilledGerard Creaner
By: Donagh Fitzgerald B.Prod Eng and Gerry Creaner B.Chem Eng. Last Updated: February 2023
GET UPDATES
Piping and Instrumentation Diagrams (P&IDs) use a standardized set of symbols, notation and abbreviations 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.
BTW, if you need to learn how to read P&IDs and qualify equipment systems within a pharmaceutical manufacturing plant, check out our Equipment Validation Training Course.
- Piping Symbols
- Pump Symbols
- Valve and Control Symbols
- Vessel Symbols
- Instrument Symbols
- Equipment Symbols
- Heat Exchanger Symbols
- Abbreviations
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
Centrifugal pump
Centrifugal pump
Gear 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
Pressure regulating valve (PRV)
Pressure safety valve (PSV)
Temperature control valve (TCV)
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.
Vessel
Pressurized horizontal vessel
Pressurized vertical vessel
Reaction vessel
Column
Packing column
Tank
Open tank
Open top tank
Closed tank
Bin
Bag
Gas bottle
Instrument 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.
Temperature Transmitter
Temperature Indicator
Temperature Controller
Conductivity Transmitter
Conductivity Indicator
Conductivity Controller
Flow Transmitter
Flow Indicator
Flow Controller
Flow Switch
Level Transmitter
Level Indicator
Level Switch
Level Alarm
Pressure Transmitter
Pressure Indicator
Pressure Controller
Equipment Symbols
Equipment is made up of items that don’t fit into other categories. This group includes hardware like reactors, dryers, turbines, vacuums, and other mechanical devices.
Jacketed mixing vessel
Half-pipe mixing vessel
Agitator or mixer
Dryer
Backdraft damper
Furnace
Cooling Tower
Air filter
Funnel
Heat Exchanger Symbols
A heat exchanger is a device that’s designed to transfer heat from different medium to another mediums. For example, an airconditor or a radiator in a house. This includes boilers, condensers, and other heat exchangers.
Heat Exchanger
Heat Exchanger
Cooler
Plate & frame heat exchanger
Fixed straight tubes heat exchanger
U-shaped tubes heat exchanger
Double pipe heat exchanger
Spiral heat exchanger
P&ID Symbols Abbreviations
P&IDs use a standardized set of notation and abbreviations to represent the various components of a process. These notations are used to indicate the type of fluid, the size, and the pressure rating of the component. These include:
CT | Conductivity Transmitter |
CI | Conductivity Indicator |
CC | Conductivity Controller |
FL | Flow Transmitter |
FI | Flow Indicator |
FC | Flow Controller |
FS | Flow Switch |
LT | Level Transmitter |
LI | Level Indicator |
LS | Level Switch |
LA | Level Alarm |
PT | Pressure Transmitter |
PI | Pressure Indicator |
PC | Pressure Controller |
PRV | Pressure Regulationg Valve |
PA | Pressure Alarm |
PC | Pressure Controller |
TT | Temperature Transmitter |
TI | Temperature Indicator |
TC | Temperature Controller |
TCV | Temperature Control Valve |
ST | Steam Trap |
SG | Sight Glass |
S | Strainer |
T | Tank |
P | Pump |
HX | Heat Exchanger |
PSV | Pressure Sanitary Valve |
PUW | Purified Water |
XV | Actuated Valves |
Further Reading
You might also be interested in:
- What is pharmaceutical validation?
- What is IQ OQ PQ?
- What is Computer System Validation (CSV)?
- What is an equipment validation protocol?
- Validation regulations
- The 8 most “in demand” skills for validation professionals
About the Author
Donagh Fitzgerald
Head of Marketing & Product Development
Mechanical/Production Engineer
Donagh looks after the marketing and product development including the training and pedagogical elements of our programs and makes sure that all GetReskilled’s users can have a great online learning experience. Donagh has lived and worked in many countries including Ireland, America, the UK, Singapore, Hong Kong and Japan. Donagh has also served as the Program Manager for the Farmleigh Fellowship based out of Singapore.
Donagh holds Degrees in Production Engineering and Mechanical Engineering from South East Technological University, Ireland.
Gerry Creaner
President
Senior Lecturer with GetReskilled
Gerry Creaner has over 30-years of experience in the Life Sciences Manufacturing industry across a range of technical, managerial and business roles. He established a very successful engineering consultancy prior to founding GetReskilled, an online education and learning business, with offices in Singapore, Ireland and Boston (USA), focussed on the manufacture of safe and effective medicines for the public.
He is also a founding Director of two Singapore based philanthropic organizations, the Farmleigh Fellowship and the Singapore-Ireland Fund, both of which deepen the well established and historical Singapore – Ireland relationship and deliver long-term benefits to both countries.
Gerry has an undergraduate degree in Chemical Engineering (UCD, 1980) and an MSc (Management) from Trinity College Dublin (2003) and is currently doing research for his Ph.D.