Samson 3256, Mounting And Operating Instructions

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9-12 EB 8065 EN
Servicing
9.4.3 Replacing the seat and
plug
Risk of control valve damage due to
incorrect servicing.
Î
Seat and plug 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 bellows
seal.
− The valve does not have a flow
divider.
− The valve does not have an AC trim.
− The standard or ADSEAL packing is
installed in the valve.
Î
To replace seat and plug in other valve
versions, contact our after-sales service.
Risk of damage to the facing of the seat
and plug due to incorrect servicing.
Î
Always replace both the seat and plug.
When replacing the seat and plug, we also
recommend replacing the packing (see sec-
tion 9.4.2).
a) Standard version
1. Unscrew the castellated nut (92) and lift
the yoke (3) off the bonnet (2).
2. Undo the body nuts (14) gradually in a
crisscross pattern.
3. Lift the bonnet (2) and plug with plug
stem (5) off the body (1).
4. Replace the gasket as described in sec-
tion 9.4.1.
5. Unthread the stem connector nut (9) and
lock nut (10) from the plug stem.
6. Unscrew the threaded bushing (8).
7. Pull the plug with plug stem (5) out of the
bonnet (2).
8. Pull the entire packing out of the packing
chamber using a suitable tool.
9. Make sure that the guide bushing (7) is
not damaged. If necessary, replace the
guide bushing using a suitable tool.
10. Unscrew the seat (4) using a suitable
tool.
11. Apply a suitable lubricant to the thread
and the sealing cone of the new seat.
12. Screw in the seat (4). Observe tightening
torques.
13. Apply a suitable lubricant to all the pack-
ing parts and to the new plug stem (5).
We recommend replacing the packing as
well. See section 9.4.2.
14. Slide the new plug with plug stem (5) in-
to the bonnet (2).
NOTICE
!
NOTICE
!
Tip