Samson 3251 - Replacing the Seat and Plug

9-14 EB 8052 EN
Servicing
4. Insert the red spacer ring (15.1) between
the threaded bushing (8) and retaining
ring. See Fig.9-4.
5. Proceed as described in “Standard pack-
ing (PTFE)”, steps13 to 16.
9.4.3 Replacing the seat and
plug
Risk of control valve damage due to incor-
rect servicing.
Î Seat and plug can only be replaced
when all the following conditions are
met:
− The nominal size is ≤NPS4.
− The valve does not have a balanced
plug.
− The valve does not have a bellows
seal.
− The valve does not have a ow divid-
er.
− The valve does not have an AC trim.
− The standard or ADSEAL packing is
installed in the valve.
− The seat is screwed into the valve
body as a separate part.
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, SAM-
SON also recommends replacing the pack-
ing (see Chapter9.4.2).
a) Standard version
1. Unscrew the castellated nut (92) and lift
the yoke (3) off the ange (2).
2. Undo the body nuts (14) gradually in a
crisscross pattern.
3. Lift the ange (2) and plug with plug
stem (5) off the body (1).
4. Replace the gasket (see Chapter9.4.1)
5. Unscrew 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
ange (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).
NOTICE
!
NOTICE
!
Tip