Brochure
Maintain optimum loop performance
Control valve performance will degrade
over time so it is vitally important that
procedures are put in place to monitor
their condition so that it is possible to
determine the optimum time to stop
and take maintenance action. The best
time to stop will be determined by a
combination of technical and economic
reasons. Wherever possible monitoring
procedures should involve minimum
intervention from site personnel and
should be able to be carried out with the
plant operational.
Performance monitoring can be per-
formed by utilising the diagnostics capa-
bilities of Fisher FIELDVUE
®
Digital Valve
Controllers, a core component of
PlantWeb digital automation architec-
ture. FIELDVUE powers PlantWeb by cap-
turing valve diagnostic data and deliver-
ing it, via AMS ValveLink
®
software to
those who can act on it. AMS ValveLink
software continually monitors FIELDVUE
alarms and alerts, under all phases of the
process cycle. Should any of the key
operating parameters of the control
valve change, indicating a potential
problem, the operators, maintenance
personnel and Emerson diagnostic tech-
nicians can be made aware, either by
PlantWeb alarm/monitoring system,
email, text message or even the produc-
tion of a works order. Consultants from
Emerson can work with site personnel or
with Emerson engineers to set the
alarms and alerts at suitable levels to
ensure they are meaningful.
On-Line testing, non-intrusive tests that
are carried out with the plant operational
and remaining under control, can be per-
formed on a routine basis to provide
information on friction and deadband;
this data can be compared to the initial
benchmark and also trended with histor-
ical data, so that potential failures can be
identified before they become function-
al failures. Test routines can be automat-
ed to minimise the involvement of site
technicians. If required, tests can be run
from a remote location by Emerson engi-
neers, utilising the communication capa-
bilities of PlantWeb architecture.
The AMS ValveLink software used to per-
form the monitoring is self documenting
and will automatically track and record
changes, easing the burden of docu-
menting maintenance information for
ISO certification or regulatory compli-
ance reporting.
FIELDVUE instrumentation
plays an important role in
Emerson’s PlantWeb
®
digital
plant architecture. PlantWeb
integrates intelligent field
devices and modular soft-
ware such as AMS predictive
maintenance software or
DeltaV™ digital automation
system software. All compo-
nents are linked by informa-
tion-rich HART
®
or
F
OUNDATION™ fieldbus proto-
cols enabling access to diag-
nostic information that can
be used as part of a predic-
tive maintenance strategy.