Preparing The Valve For Service Work; Installing The Valve After Service Work - Samson 3281 Mounting And Operating Instructions

9.2 Preparing the valve for
service work
WARNING
!
Risk of personal injury due to incorrect re-
moval of the anti-rotation fixture under ten-
sion.
Once the actuator has been mounted on the
valve and the assembly is ready for use, the
clamps (301) of the anti-rotation fixture on
the plug stem are under tension.
Î Follow the instructions in this document
during mounting or removal.
Î Do not loosen the screws (303) of the an-
ti-rotation fixture while the force generat-
ed by the supply air and/or the actuator
springs is transmitted to the actuator stem
and the stem (9).
Î First remove the actuator from the valve
or ensure it cannot transmit any forces to
the actuator stem before removing the
anti-rotation fixture on the plug stem.
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).
3. Undo the flange joint between the cool-
ing water valve and steam conditioning
valve.
4. Remove the steam conditioning valve
from the pipeline (see the 'Removal' sec-
tion).
5. Remove the actuator from the valve. See
associated actuator documentation.
EB 8251 EN
Note
To remove an actuator with "stem extends"
fail-safe action and/or with preloaded
springs, a certain signal pressure must be
applied to the actuator (see associated actu-
ator documentation). Afterwards, the signal
pressure must be removed and the air supply
disconnected again and locked.
The following service work can be per-
formed after preparation is completed:
− Replace the gaskets as described in sec-
tion 9.4.1.
− Replace the packing (see section 9.4.2)
− Replace the seat and plug (see sec-
tion 9.4.3)
− Determine the number of shims required
(see section 9.4.4).
9.3 Installing the valve after
service work
1. Mount actuator. See associated actuator
documentation and the 'Installation' sec-
tion.
2. Adjust lower or upper signal bench
range. See associated actuator docu-
mentation.
3. Install the valve into the pipeline (see the
'Installation' section).
4. Put the control valve back into operation
(see the 'Start-up' section). Observe the
requirements and conditions for start-up
or putting the valve back into operation.
Servicing
9-5