Learn P&ID Codes in Minutes

Piping and Instrumentation Diagrams (P&IDs) are the heart of the process industry, providing a visual representation of systems and activities.

Understanding P&ID codes is important for efficiency and safety while developing, maintaining, or troubleshooting systems.

Here’s a more complete collection of P&ID codes to sharpen up your knowledge.

Pipes & Lines

G-Gas

W - Water

S - Steam

D - Drain

A - Air

V - Vent

O-Oil

P- Process

C- Chemical

H - Hydraulic

I- Instrument Air

Valves

GV-Gate Valve

BV - Ball Valve

CV - Control Valve

SV - Safety Valve

PV - Pressure Relief Valve

FV - Flow Control Valve

TV - Temperature Control Valve

LV - Level Control Valve

XV - On/Off Isolation Valve

DV - Drain Valve

HV- Hand Valve

NRV - Non-Return Valve (Check Valve)

VLV - General Valve Symbol

Instruments

PT - Pressure Transmitter

PI - Pressure Indicator

PS - Pressure Switch

FT - Flow Transmitter

FI - Flow Indicator

FS - Flow Switch

TT - Temperature Transmitter

TI - Temperature Indicator

TS - Temperature Switch

LT - Level Transmitter

LI - Level Indicator

LS-Level Switch

AIT - Analytical Instrument Transmitter

PDIT - Differential Pressure Indicator Transmitter

Electrical & Control Systems

MTR – Motor

PLC - Programmable Logic Controller

DCS - Distributed Control System

ESD - Emergency Shutdown Device

SOL- Solenoid

ALM - Alarm

HS-Hand Switch

PSV - Pressure Safety Valve

Equipment

P - Pump

C- Compressor

HX - Heat Exchanger

T - Tank

V - Vessel

B - Boiler

F - Filter

M - Mixer

R- Reactor

CH - Chiller

EV - Evaporator

Safety & Miscellaneous

BDV - Blowdown Valve

PSV - Pressure Safety Valve

PRV - Pressure Relief Valve

SRV - Surge Relief Valve

FA - Fire Alarm

FG - Flare Gas

MSD - Manual Shutdown

Safety & Miscellaneous

BDV - Blowdown Valve

PSV - Pressure Safety Valve

PRV - Pressure Relief Valve

SRV - Surge Relief Valve

FA - Fire Alarm

FG - Flare Gas

MSD - Manual Shutdown

What makes these Codes important?

P&ID codes are more than just symbols; they serve as the basis for effective team communication and guarantee process safety and efficiency. Understanding the universal language of engineering is a prerequisite for mastering them.

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