UFC 3 -430-11
14 February 2001
Figure 7-1. Typical Control Loop
D
I
A5
P
4
6
7
10
FC
SP
FY
IA
A
A
M 12
D 3
2
8
1
FT
9
F.C.
11
FE
FV
LEGEND:
1.
ANALOG FLOW TRANSMITTER (FT)
2.
4-20 MADC ANALOG SIGNAL
3.
ANALOG TO DIGITAL CONVERTER
4.
DIGITAL FLOW CONTROLLER (FC)
5.
DIGITAL TO ANALOG CONVERTER
6.
4-20 MADC ANALOG SIGNAL
7.
CURRENT TO PNEUMATIC CONVERTER (FY)
8.
3-15 PSIG PNEUMATIC SIGNAL
9.
PNEUMATIC CONTROL VALVE, FAIL CLOSE (FV)
10.
INSTRUMENT AIR SUPPLY
11.
FLOW ELEMENT (FE)
12.
AUTOMATIC-MANUAL FUNCTION
SYMBOLS PER ANSI/ISA-S5.1
7-4
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