42 EB 8111/8112 EN
Servicing
7.3 Replacing the seat and
plug
Risk of damage to the facing of the seat and
plug due to incorrect service or repair.
Always replace both the seat and plug.
When replacing the seat and plug, we also
recommend replacing the at gasket and
packing. See sections7.1 and 7.2.
7.3.1 For mounting using
crossbeam and central
nut (FormB)
1. Remove the actuator from the valve. See
associated actuator documentation.
To remove the actuator from the valve, the
central nut (98) must be loosened.
2. Undo the body nuts (14) gradually in a
criss-cross pattern.
3. Lift the ange (97), ange bonnet (96),
and plug with plug stem (5) off the body
(1).
4. Unscrew the threaded bushing (8).
5. Pull the plug with plug stem (5) out of the
ange bonnet (96).
6. Pull all the packing parts out of the pack-
ing chamber using a suitable tool.
7. Unscrew the seat (4) using a suitable
tool.
8. Apply a suitable lubricant to the thread
and the sealing cone of the new seat.
9. Screw in the seat (4). Observe tightening
torques.
10. 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 section7.2.1.
11. Slide the new plug with plug stem (5) in-
to the valve body (1).
12. Place the ange bonnet (96) and the
ange (97) over the plug stem and studs
(13) onto the body.
13. Carefully slide the packing parts over the
plug stem into the packing chamber us-
ing a suitable tool. Make sure to observe
the proper sequence (see Fig.11).
14. Press the plug (5) rmly into the seat (4),
while fastening down the ange bonnet
(96) with the body nuts (14). Tighten the
nuts gradually in a criss-cross pattern.
Observe tightening torques.
15. Screw in the threaded bushing (8) and
tighten it. Observe tightening torques.
16. Mount actuator. See associated actuator
documentation.
To fasten the actuator onto the valve, the
central nut (98) must be tightened. Observe
tightening torques.
NOTICE
!
NOTICE
!
Tip
Note
Note