EB 5866 EN 9-3
Servicing
We recommend the following inspection and testing which can be performed while the pro-
cess is running:
Inspection and testing Action to be taken in the event of a negative result:
Check the markings, labels and name-
plates on the valve for their readability
and completeness.
Immediately renew damaged, missing or incorrect name-
plates or labels.
Clean any inscriptions that are covered with dirt and are il-
legible.
Check the pipe connections and gaskets
on the valve and actuator for leakage.
Check the bolted joint (tightening torque).
Check the valve's seat leakage. Shut off the section of the pipeline and ush the valve to re-
move any dirt and/or deposited foreign particles between
the seat and plug.
Check the valve for external damage
(e.g. corrosion).
Remove any damage immediately. If necessary, put the
control valve out of operation (see the 'Decommissioning'
section).
Check the valve accessories to ensure
they are mounted properly.
Tighten the connections of the valve accessories.
Check to ensure that the actuator and
plug stem move smoothly.
Unblock a blocked actuator and plug stem.
WARNING! A blocked actuator or plug stem (e.g. due to
seizing up after remaining in the same position for a long
time) can suddenly start to move uncontrollably. Injury to
hands or ngers is possible if they are inserted into the
actuator or valve.
Before trying to unblock the actuator or plug stem,
disconnect and lock the air supply or power supply as well
as the control signal. Before unblocking the actuator, release
any stored energy in the actuator (e.g. spring compression
of the Type2780 Pneumatic Actuator). See associated
actuator documentation.
If possible, check the valve's fail-safe
position by briey interrupting the air
supply.
Put the control valve out of operation (see the 'Decommis-
sioning' section). Identify the cause for the malfunction and
rectify it (see the 'Troubleshooting' section).
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