Type Av3/4 Positioner Application; Type Av3/4 Positioner Features - ABB AV3 Instruction Manual

INTRODUCTION

TYPE AV3/4 POSITIONER APPLICATION

TYPE AV3/4 POSITIONER FEATURES

TYPE AV3/4 POSITIONER APPLICATION
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A mechanical connection from the actuator (i.e., cylinder, valve,
etc.) to the position feedback cam in the positioner establishes
actual position. Three characterized segments on the cam provide
application flexibility by establishing various relationships between
the input signal and the actuator position. The characterized
curves on the cam provide:
Square root relationship.
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Linear relationship.
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Square characteristic.
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Using zero, span and gain adjustments and the cam, the actuator
can respond with characteristics specific to an application.
An optional manifold assembly provides an integral shutoff and
equalizing valve that can be used to isolate the positioner from an
actuator, allowing manual override without removing the positioner
from the process. The manifold also provides gage ports and dis-
posable filter cartridges that insure fast servicing and minimum
downtime.
The Type AV3 positioner can be equipped with either an optional
potentiometric or a four to 20 milliamp position transmitter. The
Type AV4 positioner comes standard with a four to 20 milliamp
position transmitter.
The ABB Type AV3 and Type AV4 Characterizable Pneumatic
Positioners control the position of a pneumatic actuator in a linear
or nonlinear relation to a current or pulse input signal.
Troublefree Operation. Proven pilot valve, that is quickly
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removable, provides less downtime, lower maintenance costs,
increased reliability and extended performance.
Compact Rugged Design. Die cast aluminum housing,
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beam, spring arm, follower arm and 303 stainless steel pilot
valve provide long life and maximum environmental protec-
tion. The compact housing increases mounting flexibility.
Characterizable Output. Large positioning cam can be
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shaped to provide desired relationship between the input sig-
nal and the actuator position.
Accurate Calibration. Independent zero and span adjust-
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ments eliminate interaction and provide fast and accurate cali-
bration.