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We recommend the following inspection and testing which can be performed while the pro-
cess is running:
Inspection and testing
Check the markings, labels and name-
plates on the valve for their readability
and completeness.
Check the pipe connections and gaskets
on the valve and actuator for leakage.
Check the valve's seat leakage.
Check the valve for external damage
(e.g. corrosion).
Check the valve accessories to ensure
they are mounted properly.
If possible, check the valve's fail-safe
position by briefly interrupting the air
supply.
9.2 Preparing the valve for
service work
1. Lay out the necessary material and tools
to have them ready for the service work.
2. Put the control valve out of operation (see
the 'Decommissioning' section).
Tip
We recommend removing the valve from the
pipeline before performing any service work
(see the 'Removal' section).
EB 8140 EN
Action to be taken in the event of a negative result:
Immediately renew damaged, missing or incorrect name-
plates or labels.
Clean any inscriptions that are covered with dirt and are il-
legible.
Check the bolted joint (tightening torque).
Put the control valve out of operation (see the 'Decommis-
sioning' section) and replace gaskets (see section 9.4).
Shut off the section of the pipeline and flush the valve to re-
move any dirt and/or deposited foreign particles between
the seat and plug.
Repair any damage immediately. If necessary, put the con-
trol valve out of operation (see the 'Decommissioning' sec-
tion).
Tighten the connections of the valve accessories.
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).
The following service work can be per-
formed after preparation is completed:
− Replace the gaskets (see section 9.4.1)
− Replace the packing (see section 9.4.2)
9.3 Installing the valve after
service work
1. If the valve has been removed, re-install
the valve into the pipeline (see the 'Instal-
lation' section).
2. Put the control valve back into operation
(see the 'Start-up' section). Observe the
Servicing
9-3
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