Preparing The Valve For Service Work - Samson 3253 Translation Of Original Instructions

9.2 Preparing the valve for
service work
WARNING
!
Risk of personal injury due to incorrect
removal of the anti-rotation fixture under
tension.
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
anti-rotation fixture while the force
generated 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.
NOTICE
!
Risk of control valve damage due to incor-
rect servicing.
Î The parts subject to wear can only be re-
placed when all the following conditions
are met:
− The valve size is ≤DN 100.
− The valve does not have a balanced
plug.
− The valve does not have a flow
divider.
− The valve does not have a bellows
seal.
EB 8055 EN
− The standard or ADSEAL packing is
installed in the valve.
Î To replace parts subject to wear in other
valve versions, contact our After-sales
Service.
NOTICE
!
Risk of damage to the facing of the seat
and plug due to incorrect servicing.
Î Always replace both the seat and plug.
Î We recommend replacing all the parts
subject to wear (gasket, packing, seat
and plug) at the same time.
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. Remove the valve from the pipeline (see
the 'Removal' section).
4. Remove the actuator from the valve. See
associated actuator documentation.
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.
Servicing
9-5