Acronyms Used in P&ID

AHU -- AIR HANDLING UNIT
ASV-- AIR SWITCH VALVE
CA -- AIR COMPRESSOR
CAE -- COOLER, AIR EVAPORATIVE
D -- DAMPER
ADA -- DESICCANT AIR DRYER
DAMD -- DUCT AIR MONITOR DEVICE
ES -- EXHAUST STACK
FAB -- FILTER AIR BOX
FANE -- FAN EVALUATOR
FAR -- FILTER AIR REPLACEABLE
FC -- FAN CIRCULATING
FD -- FIRE DAMPER
FE -- FAN EXHAUST
FRA -- FAN, RETURN AIR
FRL -- FILTER AIR ROLL
FA -- FAN SUPPLY
HEAP -- HIGH EFFICIENCY PARTICULAR AIR FILTER
HX -- HEAT EXCHANGER

MT -- MOISTURE TRAP
OIM -- OPERATOR INTERFACE MODULE
SST -- SYSTEM STATIC TOTALIZER
TCA -- TANK COMPRESSED AIR
TK -- TANK
T -- TRAP
V -- VALVE
VFD -- VARIABLE FREQUENCY DRIVE/MOTOR CONTROLLER
AW -- Acid waste
NW -- Normal waste
OW -- Oil waste
SW -- Sanitary waste
FA -- Flame arrester
ND -- Non-radioactive drain
SPR -- Separator
SR -- Strainer
SRY -- Y-type strainer
SRT -- T-type strainer
SRB -- Bucket type strainer
TS -- Temporary strainer SIL - Silencer
SG -- Slight glass
SC -- Sample cooler
DF -- Drain funnel
LM -- Line mixer
RO -- Restriction orifice
MO -- Mixing orifice
RD -- Rupture disk
EJ -- Expansion joint

PID Examples

Air Conditioning PID

Thermal System PID

Power Generation Heating PID