ANSI/ISA-S5.1-1984 (R 1992) 21
Table 1 Identification Letters
NOTE: Numbers in parentheses refer to specific explanatory notes in Section 5.1.
FIRST-LETTER (4) SUCCEEDING-LETTERS (3)
MEASURED OR INITIATING VARIABLE MODIFIER
READOUT OR PASSIVE
FUNCTION OUTPUT FUNCTION MODIFIER
A Analysis (5,19) Alarm
B Burner, Combustion User's Choice (1) User's Choice (1) User's Choice (1)
C User's Choice (1) Control (13)
D User's Choice (1) Differential (4)
E Voltage Sensor (Primary Element)
F Flow Rate Ratio (Fraction) (4)
G User's Choice (1) Glass, Viewing Device (9)
H Hand High (7, 15, 16)
I Current (Electrical) Indicate (10)
J Power Scan (7)
K Time, Time Schedule Time Rate of Change (4, 21)
Control Station (22)
L Level Light (11) Low (7, 15, 16)
M User's Choice (1) Momentary (4) Middle, Intermediate (7,15)
N User's Choice (1) User's Choice (1) User's Choice (1) User's Choice (1)
O User's Choice (1) Orifice, Restriction
P Pressure, Vacuum Point (Test) Connection
Q Quantity Integrate, Totalize (4)
R Radiation Record (17)
S Speed, Frequency Safety (8) Switch (13)
T Temperature Transmit (18)
U Multivariable (6) Multifunction (12) Multifunction (12) Multifunction (12)
V Vibration, Mechanical Analysis (19)
Valve, Damper, Louver (13)
W Weight, Force Well
X Unclassified (2) X Axis Unclassified (2) Unclassified (2) Unclassified (2)
Y Event, State or Presence (20)
Y Axis Relay, Compute, Convert (13, 14, 18)
Z Position, Dimension Z Axis Driver, Actuator, Unclassified Final Control Element
22 ANSI/ISA-S5.1-1984 (R 1992)
Tabl
e 2
T
ypic
al L
ette
r Com
bina
tions
Not
e: T
his
tabl
e is
not
all-
incl
usiv
e.
Oth
er P
ossi
ble
Com
bina
tions
:*A
, ala
rm, t
he a
nnun
ciat
ing
devi
ce, m
ay b
e us
ed in
the
sam
eFO
(Res
trict
ion
Orif
ice)
PFR
(Rat
io)
fash
ion
as S
, sw
itch,
the
actu
atin
g de
vice
.FR
K, H
IK(C
ontro
l Sta
tions
)K
QI
(Run
ning
Tim
e In
dica
tor)
FX(A
cces
sorie
s)Q
QI
(Indi
catin
g C
ount
er)
**Th
e le
tters
H a
nd L
may
be
omitt
ed in
the
unde
fined
cas
e.TJ
R(S
cann
ing
Rec
orde
r)W
KIC
(Rat
e-of
-Wei
ght-L
oss
Con
trolle
r)LL
H(P
ilot L
ight
)H
MS
(Han
d M
omen
tary
Sw
itch)
Firs
t-Le
tters
Initi
atin
g or
M
easu
red
Vaia
ble
Con
trol
lers
Rea
dout
Dev
ices
Switc
hes
and
Ala
rm D
evic
es*
Tran
smitt
ers
Sole
noid
s,
Rel
ays,
C
ompu
ting
Dev
ices
Prim
ary
Elem
ent
Test
Po
int
Wel
l or
Pr
obe
View
ing
Dev
ice,
G
lass
Safe
ty
Dev
ice
Fina
l El
emen
tR
ecor
ding
Indi
catin
gB
lind
Self-
Act
uate
d C
ontro
l Va
lves
Rec
ordi
ng
Indi
catin
gH
igh*
*Lo
wC
omb
Rec
ordi
ngIn
dica
ting
Blin
dA
Ana
lysi
sAR
CA
ICAC
AR
AI
ASH
ASL
ASH
LA
RT
AIT
ATAY
AEA
PAW
AV
BB
urne
r/Com
bust
ion
BRC
BIC
BCB
RB
IBS
HBS
LBS
HL
BR
TB
ITBT
BY
BEBW
BGBZ
CU
sers
Cho
ice
DU
sers
Cho
ice
EVo
ltage
ERC
EIC
ECE
RE
IES
HES
LES
HL
ER
TE
ITET
EY
EEEZ
FFl
ow R
ate
FRC
FIC
FCFC
V,FI
CV
FRFI
FSH
FSL
FSH
LFR
TFI
TFT
FYFE
FPFG
FV
FQFl
ow Q
uant
ityFQ
RC
FQIC
FQR
FQI
FQS
HFQ
SL
FQIT
FQT
FQY
FQE
FQV
FFFl
ow R
atio
FFR
CFF
ICFF
CFF
RFF
IFF
SH
FFS
LFE
FFV
GU
sers
Cho
ice
HH
and
HIC
HC
HS
HV
IC
urre
ntIR
CIIC
IRII
ISH
ISL
ISH
LIR
TIIT
ITIY
IEIZ
JPo
wer
JRC
JIC
JRJI
JSH
JSL
JSH
LJR
TJI
TJT
JYJE
JV
KTi
me
KRC
KIC
KCK
CV
KR
KI
KSH
KSL
KSH
LK
RT
KIT
KTK
YKE
KV
LLe
vel
LRC
LIC
LCLC
VLR
LILS
HLS
LLS
HL
LRT
LIT
LTLY
LELW
LGLV
MU
sers
Cho
ice
NU
sers
Cho
ice
OU
sers
Cho
ice
PP
ress
ure/
Va
cuum
PRC
PIC
PCP
CV
PR
PI
PSH
PSL
PSH
LP
RT
PIT
PTP
YPE
PP
PS
V,P
SE
PV
PD
Pre
ssur
e,
Diff
eren
tial
PDR
CP
DIC
PDC
PD
CV
PD
RP
DI
PD
SH
PDS
LP
DR
TP
DIT
PDT
PDY
PEP
PP
DV
uant
ityQ
RC
QIC
QR
QI
QSH
QSL
QSH
LQ
RT
QIT
QT
QY
QE
QZ
RR
adia
tion
RR
CR
ICR
CR
RR
IR
SH
RS
LR
SH
LR
RT
RIT
RT
RY
RE
RW
RZ
SS
peed
/Fre
quen
cySR
CS
ICSC
SC
VS
RS
ISS
HSS
LSS
HL
SR
TS
ITST
SY
SES
VT
Tem
pera
ture
TRC
TIC
TCTC
VTR
TITS
HTS
LTS
HL
TRT
TIT
TTTY
TETP
TWTS
ETV
TDTe
mpe
ratu
re,
D
iffer
entia
lTD
RC
TDIC
TDC
TDC
VTD
RTD
ITD
SH
TDSL
TDR
TTD
ITTD
TTD
YTE
TPTW
TDV
UM
ultiv
aria
ble
UR
UI
UY
UV
VV
ibra
tion/
Mac
hine
ry
Ana
lysi
sV
RV
IVS
HVS
LVS
HL
VR
TV
ITVT
VY
VEVZ
WW
eigh
t/For
ceW
RC
WIC
WC
WC
VW
RW
IW
SHW
SLW
SHL
WR
TW
ITW
TW
YW
EW
Z
WD
Wei
ght/F
orce
,
Diff
eren
tial
WD
RC
WD
ICW
DC
WD
CV
WD
RW
DI
WD
SHW
DSL
WD
RT
WD
ITW
DT
WDY
WE
WD
Z
XU
ncla
ssifi
edY
Eve
nt/S
tate
/Pre
senc
eY
ICYC
YR
YI
YSH
YSL
YTY
YYE
YZ
ZPo
sitio
n/D
imen
sion
ZRC
ZIC
ZCZC
VZR
ZIZS
HZS
LZS
HL
ZRT
ZIT
ZTZY
ZEZV
ZDG
augi
ng/D
evia
tion
ZDR
CZD
ICZD
CZD
CV
ZDR
ZDI
ZDS
HZD
SLZD
RT
ZDIT
ZDT
ZDY
ZDE
ZDV
5.3
ANSI/ISA-S5.1-1984 (R 1992) 23
Tabl
e 3
F
unct
ion
Blo
cks
- Fun
ctio
n D
esig
natio
nsTH
E F
UN
CTI
ON
DE
SIG
NAT
ION
S A
SS
OC
IATE
D W
ITH
CO
NTR
OLL
ER
S, C
OM
PU
TIN
G D
EV
ICE
S, C
ON
VE
RTE
RS
AN
D
RE
LAY
S M
AY B
E U
SE
D IN
DIV
IDU
ALL
Y O
R IN
CO
MB
INAT
ION
(ALS
O, S
EE
TA
BLE
1, N
OTE
14.
). TH
E U
SE
OF
A BO
X AV
OID
S C
ON
FUS
ION
BY
SE
TTIN
G O
FF T
HE
SYM
BOL
FRO
M O
THE
R M
AR
KIN
GS
ON
A D
IAG
RA
M
AN
D P
ER
MIT
S T
HE
FU
NC
TIO
N T
O B
E U
SE
D A
S A
STA
ND
-ALO
NE
BLO
CK
ON
CO
NC
EP
TUA
L D
ES
IGN
S.
5.4
24 ANSI/ISA-S5.1-1984 (R 1992)
5.4
Tabl
e 3
C
ontin
ued
ANSI/ISA-S5.1-1984 (R 1992) 25
5.4
Tabl
e 3
C
ontin
ued
26 ANSI/ISA-S5.1-1984 (R 1992)
5.4
Tabl
e 3
C
ontin
ued
ANSI/ISA-S5.1-1984 (R 1992) 27
6 Drawings
6.1 Cautionary notes
1) If a given drawing, or set of drawings, uses graphic symbols that are similar or identical in shape or configuration and that have different meanings because they are taken from different standards, then adequate steps must be taken to avoid misinterpretation of the symbols used. These steps may be to use caution notes, reference notes, comparison charts that illustrate and define the conflicting symbols, or other suitablemeans. This requirement is especially critical in cases where symbols taken from different disciplines are intermixed and their misinterpretation might cause danger to personnel or damage to equipment.
2) The titles Simplified Diagrams, Conceptual Diagrams and Detailed Diagrams of Section 6.12 were chosen to represent a cross section of symbol usage, not any particular generic document. (See 4.4.10 for a more complete discussion.)
3) The line symbols of Section 6.2 offer "user's choice" alternative electrical symbols and optional binary symbols. The subsequent examples use one consistent set of these alternatives and apply the binary options. This was done for consistency of appearance of the standard.
It is recommended that the user choose either the dashed line electrical symbol orthe triple cross hatch symbol and apply it consistently. The optional binary (on-off)symbols are available for those applications where the user finds it necessary todistinguish between analog and binary signals. If, in the user's judgment, the ap-plication does not require such differentiation, the reverse slash may be omittedfrom on-off signal line symbols. Consistency is recommended on a given set ofdocuments.
28 ANSI/ISA-S5.1-1984 (R 1992)
6.2 Instrument line symbolsALL LINES TO BE FINE IN RELATION TO PROCESS PIPING LINES.
ANSI/ISA-S5.1-1984 (R 1992) 29
6.3 General instrument or function symbols
30 ANSI/ISA-S5.1-1984 (R 1992)
6.3 General instrument or function symbols (contd.)
ANSI/ISA-S5.1-1984 (R 1992) 31
6.4 Control valve body symbols, damper symbols
32 ANSI/ISA-S5.1-1984 (R 1992)
6.5 Actuator symbols
ANSI/ISA-S5.1-1984 (R 1992) 33
6.5 Actuator symbols (contd.)
34 ANSI/ISA-S5.1-1984 (R 1992)
6.6 Symbols for self-actuated regulators, valves, and other devices
ANSI/ISA-S5.1-1984 (R 1992) 35
6.6 Symbols for self-actuated regulators, valves, and other devices (contd.)
36 ANSI/ISA-S5.1-1984 (R 1992)
6.6 Symbols for self-actuated regulators, valves, and other devices (contd.)
ANSI/ISA-S5.1-1984 (R 1992) 37
6.7 Symbols for actuator action in event of actuator power failure (shown typically for diaphragm-actuated control valve).
38 ANSI/ISA-S5.1-1984 (R 1992)
6.8 Primary element symbols
ANSI/ISA-S5.1-1984 (R 1992) 39
6.8 Primary element symbols (contd.)
40 ANSI/ISA-S5.1-1984 (R 1992)
6.8 Primary element symbols (contd.)
ANSI/ISA-S5.1-1984 (R 1992) 41
6.8 Primary element symbols (contd.)
42 ANSI/ISA-S5.1-1984 (R 1992)
6.8 Primary element symbols (contd.)
ANSI/ISA-S5.1-1984 (R 1992) 43
6.8 Primary element symbols (contd.)
44 ANSI/ISA-S5.1-1984 (R 1992)
6.8 Primary element symbols (contd.)
ANSI/ISA-S5.1-1984 (R 1992) 45
6.8 Primary element symbols (contd.)
46 ANSI/ISA-S5.1-1984 (R 1992)
6.8 Primary element symbols (contd.)
ANSI/ISA-S5.1-1984 (R 1992) 47
6.8 Primary element symbols (contd.)
48 ANSI/ISA-S5.1-1984 (R 1992)
6.9 Examples functions
ANSI/ISA-S5.1-1984 (R 1992) 49
6.9 Examples functions (contd.)
50 ANSI/ISA-S5.1-1984 (R 1992)
6.9 Examples functions (contd.)
ANSI/ISA-S5.1-1984 (R 1992) 51
6.9 Examples functions (contd.)
52 ANSI/ISA-S5.1-1984 (R 1992)
6.9 Examples functions (contd.)
ANSI/ISA-S5.1-1984 (R 1992) 53
6.9 Examples functions (contd.)
54 ANSI/ISA-S5.1-1984 (R 1992)
6.9 Examples functions (contd.)
ANSI/ISA-S5.1-1984 (R 1992) 55
6.9 Examples functions (contd.)
56 ANSI/ISA-S5.1-1984 (R 1992)
6.10 Examples miscellaneous combinations
ANSI/ISA-S5.1-1984 (R 1992) 57
6.10 Examples miscellaneous combinations (contd.)
58 ANSI/ISA-S5.1-1984 (R 1992)
6.10 Examples miscellaneous combinations (contd.)
ANSI/ISA-S5.1-1984 (R 1992) 59
6.10 Examples miscellaneous combinations (contd.)
60 ANSI/ISA-S5.1-1984 (R 1992)
6.10 Examples miscellaneous combinations (contd.)
ANSI/ISA-S5.1-1984 (R 1992) 61
6.11 Example complex combinations
62 ANSI/ISA-S5.1-1984 (R 1992)
6.12 Example degree of detail*
ANSI/ISA-S5.1-1984 (R 1992) 63
6.12 Example degree of detail (contd.)*
64 ANSI/ISA-S5.1-1984 (R 1992)
6.12 Example degree of detail (contd.)*
Top Related