INTRODUCTION
2 - 1
SECTION 2 - DESCRIPTION AND OPERATION
INTRODUCTION
This section describes and explains the functional and physical
operation of Type AV1 and AV2 positioners. Figure 2-1 diagrams
the operating principles of the positioners. Figure 2-2 shows the
placement of a positioner in a typical control system.
Figure 2-1. Operation Diagram
PILOT VALVE
CAM
SIGNAL
DIAPHRAGM
DIAPHRAGM
FORCE
RANGE
SPRING
FORCE
RANGE
SPRING
T00354A
GAIN
HINGE
SPRING
BALANCE
BEAM
INPUT
SIGNAL
PRESSURE
SUPPLY PRESSURE
TO ACTUATOR
TO ACTUATOR
O1
O2
S
Figure 2-2. Block Diagram
+
–
+
–
SET
POINT
+
–
CONTROLLER
POSITION
TRANSMITTER
(OPTIONAL)
POSITIONER ACTUATOR PROCESS
OUTPUT
LOAD
T00770A
LINKAGE
PROCESS FEEDBACK