Preparing The Valve For Service Work; Mounting The Valve After Service Work; Service Work; Replacing The Gasket - Samson 3256 Mounting And Operating Instructions

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).
3. 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.
Tip
We recommend removing the valve from the
pipeline before performing any service work
(see the 'Removal' section).
The following service work can be per-
formed after preparation is completed:
− Replacing the gasket (see section 9.4.1)
− Replacing the packing (see section 9.4.2)
− Replacing the seat and plug (see sec-
tion 9.4.3)
EB 8065 EN
9.3 Mounting the valve after
service work
1. Mount actuator. See associated actuator
documentation.
2. Adjust lower or upper signal bench
range. See associated actuator docu-
mentation.
3. 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.
9.4 Service work
Î Before performing any service work,
preparations must be made to the control
valve (see section 9.2).
Î After all service work is completed, check
the control valve before putting it back
into operation (see 'Testing the installed
valve' in the 'Installation' section).
9.4.1

Replacing the gasket

NOTICE
!
Risk of control valve damage due to
incorrect servicing.
Î The gasket can only be replaced 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.
Servicing
9-5