Instrument Abbreviation

Instrument Abbreviation	Expansion	Functions Performed
FC	Flow controller	Flow measurement and control
LC	Level controller	Level control
FE	Flow element	Flow sensor
LG	Level gauge	Level measurement
FIC	Flow indicator and controller	Indicating flow as well as controlling flow
LA	Level alarm	Indicating level alarm
FR	Flow recorder	Recording flow
LAH	Level alarm high	Indicating high level
FRC	Flow recorder and controller	Flow recording; controlling flow
LAHH	Level alarm high high	Indicating very high level
FT	Flow transmitter	Transmitting flow signal
LAL	Level alarm low	Indicating low level
FA	Flow alarm	Indicating flow alarm
LI	Level indicator	Level indication
LIC	Level indicator and controller	Indicating level; controlling level
PC	Pressure controller	controlling pressure
TC	Temperature controller	Controlling/regulating temperature
PI	Pressure indicator	Indicating pressure
TI	Temperature indicator	Indicating pressure
PIC	Pressure indicator and controller	Indicating pressure; controlling pressure
TIC	Temperature indicator and controller	Indicating temperature; controlling temperature
PR	Pressure recorder	Recording pressure
TR	Temperature recorder	Recording temperature
PRC	Pressure recorder and controller	Recording pressure; controlling pressure
TRC	Temperature recorder and controller	Recording temperature; controlling temperature
PSV	Pressure safety valve	Relieving excess pressure in case of high pressure situation
TT	Temperature transmitter	Transmitting measured temperature signals
PT	Pressure transmitter	Transmitting measured pressure signals
TW	Thermowell	Houses temperature sensors
RV	Relief valve	To relieve excess pressure in case of high pressure
TY	Temperature relay/transducer	Converts electrical signals to pneumatic signals
PSH	Pressure switch high	A pressure switch used to indicate high pressure alarm
ZI	Position/limit indicator	Indicates whether a valve is open or close
SDV	Shut down valve	A valve initiating shutdown
ZSC	Position/unit switch closed	Limit switch indicating a valve is closed
ZSO	Position/unit switch open	Limit switch indicating a valve is open
SDY	Shutdown relay	A transducer attached to a shutdown valve
USD	Unit shutdown