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VSS/VSM/VSH/VSSH • Installation, Operation and Maintenance Manual • Emerson • 35391SD
Instrument Identication Letters
Use this list to identify components shown in the Piping & Identication Diagram.
A Analysis
AAH Concentration High
AAHH Concentration/Detection
High High
AI Analysis/Moisture
Indicator
AIT Analysis/Detection
Indicating Transmitter
AT Analysis/Detection (Blind)
AU Analysis/Detection
Monitor
BFV Buttery Valve
CV Check Valve
E Voltage
EAH Voltage High
EAHH Voltage High High
(Shutdown)
EI Voltage Indication
F Flow
FAH Flow High
FAHH Flow High High
(Shutdown)
FAL Flow Low
FALL Flow Low Low
FC Flow Controller/Fail Close
FG Flow Gauge
FI Flow Indication (Soft)/
Flow Sight Indicator
(Glass)
FIC Flow Indicating Controller
FIT Flow Indicating
Transmitter
FOP Orice Plate
FT Flow Transmitter (Blind)
FV Flow Control Valve
FY Flow/Relay/Convertor
G Gas
GIT Gas Detecting Indicating
Transmitter
GAH Gas Detected
Concentration Level High
GAHH Gas Detected
Concentration Level High
High (Shutdown)
H Hand
HH Hand Hole
HO Held Open (Solenoid
Valve Only)
HV Hand Valve
I Current
IAH Amperage High
IAHH Amperage High High
(Shutdown)
II Current Indication
IT Current Transmitter
(Blind)
J Power
JB Junction Box (Wire
Termination)
JI Power Indication
JIT Power Indicating
Transmitter
JT Power Transmitter (Blind)
K Time Schedule
KC Time Controller (Blind)
KI Time Indication
KIC Time Indication Controller
KR Time Recorder
KY Time/Relay/Convertor
L Level
LAH Liquid Level High
LAHH Liquid Level High High
(Shutdown)
LAL Liquid Level Low
LALL Liquid Level Low Low
(Shutdown)
LC Level Controller
LE Level Probe (Element)
LG Level Gauge
LI Indication (Soft)/Level
Sight Indicator (Glass)
LIT Level Indicating
Transmitter
LO Lock Open
LSH Level Switch High
LSHH Level Switch High High
(Shutdown)
LSL Level Switch Low
LSLL Level Switch Low Low
(Shutdown)
LT Level Transmitter (Blind)
LV Level Control Valve
LY Level/Relay/Convertor
MCC Motor Control Center
MGV Manifold Gauge Valve
NC Normally Closed
NO Normally Open
NV Needle Valve
P Pressure
PAH Pressure High
PAHH Pressure High High
(Shutdown)
PAL Pressure Low
PALL Pressure Low Low
PC Pressure Control
PDAH Pressure Differential High
PDAHH Pressure Differential High
High (Shutdown)
PDAL Pressure Differential Low
PDALL Pressure Differential Low
Low (Shutdown)
PDC Pressure Differential
Control
PDI Differential Pressure
Indication
PDIC Pressure Differential
Indicating Controller
Section 1 • General Information