Flowserve Logix MD+ ValveSight - Manual (Page 30)

ValveSight™ Diagnostics DTM Manual for Logix MD+ Positioner with HART®
FCD- LGENSF0014-00
© Flowserve Corporation
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Implications: The bellows may be reaching the end of its fatigue
life. Each cycle represents two reversals of the direction of valve
movement. The cycle counting criterion and count limit are set by the
user to track the usage of the valve.
•
Possible Solutions: Follow routine procedures for maintenance when
the limit is reached such as checking bellows for cracking or
leaking. After maintenance, reset the cycle accumulator.
Pilot Cycle
•
Definition: The pilot relay cycle limit set by the user has been
exceeded.
•
Implications: The pilot relay cycles indicate the activity level of the pilot
relay as it maintains a valve’s position. Excessive cycles can contribute
to a worn relay which can lead to high air consumption.
•
Possible Solutions: Inspect for high air consumption and signs of
wear.
Pilot Travel
•
Definition: The total accumulated pilot relay travel (% of full relay span)
set by the user has been exceeded.
•
Implications: The pilot relay travel indicates the activity level of the
relay as it maintains a valve’s position. Excessive travel can contribute
to a worn pilot relay which can lead to high air consumption.
•
Possible Solutions: Inspect for high air consumption and signs of
wear.
Feedback Loop Status
Position Deviation
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Definition: The device is not controlling at the set point.
•
Implications: The difference between the command and the actual
position has been greater than the user-set limit for longer than a user-
set time.
•
Possible Solutions: Review active alarms and warnings to find root
causes of this alarm. The deviation settings can be changed in the
Valve Health page of the DTM.
Position Sensor Fail
•
Definition: The feedback arm may be disconnected from the valve
assembly.
•
Implications: The feedback arm may be disconnected from the valve
assembly or the sensor has failed.