Flowserve Logix MD+ ValveSight - Manual (Page 31)

ValveSight™ Diagnostics DTM Manual for Logix MD+ Positioner with HART®
FCD- LGENSF0014-00
© Flowserve Corporation
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Possible Solutions: Check the feedback arm linkage. Recalibrate. If
the problem persists return the unit for repair.
Closed Too Far
•
Definition: The valve has closed farther than it did at the last
calibration.
•
Implications: While the valve was in use, it closed farther than it did at
the last calibration by 0.5%.
•
Possible Solutions: Check the feedback arm linkage and ensure the
valve stem connection is tight. Recalibrate the stroke. If the process
cannot be interrupted a service technician may be able to adjust the
calibration.
Opened Too Far
•
Definition: The valve has opened farther than it did at the last
calibration.
•
Implications: While the valve was in use, it opened farther than it did at
the last calibration by 0.5%.
•
Possible Solutions: Check the feedback arm linkage and ensure the
valve stem connection is tight. Recalibrate the stroke. If the process
cannot be interrupted a service technician may be able to adjust the
calibration.
PST Failed -
•
Definition: Measured times or forces during the last partial stroke test
did not pass the criteria set by the user.
•
Implications: This may be an indication of corrosion build-up on the
valve stem or in the actuator, low or restricted supply pressure, or a
sticking positioner relay.
•
Possible Solutions: This warning will clear upon completion of a
successful partial stroke test.
CST Failed
•
Definition: During the continuous stroke test, the valve did not move
after 5 consecutive attempts.
•
Implications: This could mean the valve has increased friction, a
change in process load or inadequate supply pressure.
•
Possible Solutions: Check friction, supply pressure and other alarms
or warnings that would indicate difficulty in moving the valve. Check
packing, and air supply. The warning will clear when the CST function
is turned off or when a successful attempt to move the valve occurs.
Inner Loop Status