What is P & ID?
P&ID stands for “process and instrumentation diagram,” and it is a detailed graphic representation of a process that also includes the hardware and software required to design, construct, and control the facility. This representation is applicable in the Process Industry Practices (PIP).
Valve PID Symbol:
Line PID Symbol:
SYMBOL | FUNCTION |
---|
 | Future Equipment |
 | Major Process |
 | Minor Process |
 | Pneumatic Signal |
 | Hydraulic Signal |
 | Capillary Tubing |
 | Mechanical Link Signal |
 | Electromagnetic, Sonic, Optical, Nuclear Signal |
 | Electric Signal |
 | Connecting Line |
 | Non-Connecting Line |
 | Non-Connecting Line |
 | Jacketed or Double Containment |
 | Data or Software Link |
 | Self Contained Regulator |
Instrument PID Symbol:
CIRCLE AND LETTERS REPRESENTATION | FUNCTION |
---|
 | A circle with letters represents a field or locally mounted instrument |
A | Analysis |
B | Burner |
C | Combustion |
D | Differential |
E | Voltage |
F | Flow Rate |
G | User Choice’s (1) |
H | Hard |
I | Current |
J | Power |
K | Time, Time Schedule |
L | Level |
M | Momentary |
N | User Choice’s (1) |
O | User Choice’s (1) |
P | Pressure, Vacuum |
Q | Quantity |
R | Radiation |
S | Speed, Frequency |
T | Temperature |
U | Multi-variable |
V | Vibration |
W | Weight, Force |
X | Unclassified |
Y | State or Presence |
Z | Position, Dimension |
FC | Flow Controller |
FE | Flow Element |
FI | Flow Indicator |
FT | Flow Transmitter |
FS | Flow Switch |
FIC | Flow Indicating Controller |
FCV | Flow Control Valve |
FRC | Flow Recording Controller |
LC | Level Controller |
LG | Level Gauge |
LR | Level Recorder |
LT | Level Transmitter |
LS | Level Switch |
LIC | Level Indicating Controller |
LCV | Level Control Valve |
LRC | Level Recording Controller |
PC | Pressure Controller |
PG | Pressure Gauge |
PI | Pressure Indictor |
PR | Pressure Recorder |
PS | Pressure Switch |
PT | Pressure Transmitter |
PIC | Pressure Indicating Controller |
PCV | Pressure Control Valve |
PRC | Pressure Recording Controller |
PDI | Pressure Differential Indicator |
PDR | Pressure Differential Recorder |
PDS | Pressure Differential Switch |
PDT | Pressure Differential Transmitter |
PTD | Pressure Transducer |
TC | Temperature Controller |
TE | Temperature Element |
TR | Temperature Recorder |
TS | Temperature Switch |
TT | Temperature Transmitter |
TI | Temperature Indicator |
Mechanical PID Symbol:
SYMBOL | FUNCTION |
---|
 | Heater |
 | Vessel or Reactor |
 | Heat Exchanger |
 | Pipe |
 | Pump |
 | Flow Direction of Pump |
 | Boiler |
 | Centrifugee |
 | Cylinder or Horizontal Tank |
 | Liquid Mixer |
 | Reaction Chamber |
 | Distillation Column |
 | Absorber |
 | Stripper |
 | Diesel Motor |
 | Agitator or Mixer |
 | Liquid Flow rate |
 | Gas Flow rate |
 | Crossflow Cooling Tower |
 | Chimney Cooling Tower |
 | Fan |
Pump PID Symbol:
SYMBOL | FUNCTION |
---|
 | Centrifugal Pump |
 | Horizontal Pump |
 | Vertical Pump |
 | Sump Pump |
 | Positive Displacement Pump |
 | Progressive Cavity Pump |
 | Screw Pump |
 | Vacuum Pump |
 | Reciprocating Pump |
 | Positive Displacement Pump |
 | Gear Pump |
 | Vertical Can Pump |
Compressor PID Symbol:
SYMBOL | FUNCTION |
---|
 | Centrifugal Compressor |
 | Centrifugal Blower |
 | Turbine Driven Centrifugal Compressor |
 | Axial Compressor |
 | Reciprocating Compressor |
 | Rotary Compressor |
 | Rotary Compressor & Silencer |
 | Liquid Ring Vacuum |
 | Rotary Screw Compressor |
 | Positive Displacement Blower |
Pipe PID Symbol:
SYMBOL | FUNCTION |
---|
 | Generic Pipe |
 | Threaded Pipe |
 | Socket Welded Pipe |
 | Flanged Pipe |
 | Heat/Cool Traced Pipe |
 | Direct Welded Pipe |
HEAT Exchanger PID Symbol:
SYMBOL | FUNCTION |
---|
 | Plate and Frame Heat Exchanger |
 | Hairpin Exchanger |
 | Air Cooled Exchanger |
 | U-Tube Heat Exchanger |
 | Double-Pipe Heat Exchanger |
 | Single Pass Heat Exchanger |
 | Spiral Heat Exchanger |
 | Reboiler |
 | Heater |
 | Condenser |
 | Shell and Tube Heat Exchanger |
Function PID Symbol:
SYMBOL | FUNCTION |
---|
 | Field |
 | Control Panel |
 | DCS |
 | PLC |
Actuator PID Symbol:
SYMBOL | FUNCTION |
---|
 | Manual Actuator |
 | Spring Diaphragm Actuator |
 | Linear Piston Pneumatic Actuator |
 | Rotary Piston Pneumatic Actuator |
 | Rotary Motor Actuator |
Positioner PID Symbol:
SYMBOL | FUNCTION |
---|
 | Positoner |
 | Fail Positioner |
 | Manual Override Positioner |