Masoneilan SVI II AP Installation and Maintenance ... - GE Energy

GE Oil and Gas
SVI II AP Instruction Manual
Characteristic
Closed
Compliance Voltage
Conformity
Compliance, HART
Condition Monitoring
CONFIGure
Custom
The positioner input setpoint command can be selectively modified
to provide a desired relationship between setpoint and valve
position. In the valve, the relationship between stroke and Cv is
also called valve inherent characteristic. It is often adjusted by
design, to equal percentage, for example. The positioner characteristic
is applied to modify the setpoint to travel relationship of
the actuator. The characteristic of the positioner must be chosen
to compliment the valve. If the valve is equal percentage, set the
positioner to linear. If a linear valve is installed the positioner can
be set to an equal percentage characteristic to improve flow control.
SVI II AP offers an eleven point custom characteristic option
that can be created and edited in ValVue. Local display can be
used to select the custom characteristic, but cannot adjust the
points.
The valve position in which the flow is minimum or zero. See
Tight Shutoff.
The voltage that must be available at the control system output in
order to drive the control current through the SVI II AP and all the
resistive devices in series with it.
The closeness to which the position approaches the theoretical
position curve, for example equal percentage or quick opening. It
is independent of effects due to valve or actuator rigidity at the
mechanical limits of travel. See Accuracy.
Manufactured and tested in accordance with the HART Communications
Foundation standards.
A technology for measuring the performance of process equipment
and valves over a period of time to predict the need for
maintenance. The technology evolved to meet NRC requirements
GL 89-10, and has proven valuable to other process industries.
SVI II AP and ValVue offer a suite of diagnostic tools to implement
condition monitoring.
A mode of the positioner where you can change permanent
parameters required for position control or for communications.
The custom characteristic in the SVI II AP has ten points to define
the (See Characteristic) relationship between the setpoint and the
valve position. The pushbuttons allow selection of the custom
characteristic that must be downloaded as pairs of data using the
HART communications from a HART master. ValVue offers a
graphical drag-and-drop method to define the characteristic. It
includes a method to correct for geometric non-linearity of the
positioner feedback linkage.
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