8-2 EB 5868-1 EN
Malfunctions
8.2 Emergency action
The valve, on which the actuator with fail-
safe action is mounted, is moved to its fail-
safe position upon failure of the supply volt-
age (see the 'Design and principle of opera-
tion' section).
Plant operators are responsible for emergen-
cy action to be taken in the plant.
In the event of a valve malfunction:
1. Close the shut-off valves upstream and
downstream of the control valve to stop
the process medium from owing
through the valve.
2. Perform troubleshooting (see sec-
tion8.1).
3. Rectify those malfunctions that can be
remedied based on the instructions pro-
vided here. Contact our after-sales ser-
vice in all other cases.
Putting the device back into operation after
a malfunction
See the 'Start-up' section.
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