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EB 8072 EN
9-13
Servicing
9.4.4 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 valve does not have a balanced
plug.
− The valve does not have a bellows
seal.
− The standard, form HT 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 service or repair.
Î
Always replace both the seat and plug.
In versions with flow divider, it takes over the
function as a seat retainer (124), i.e. the seat
(4) is clamped in place by the flow divider
(62).
1.
Unscrew the castellated nut (92) and take
the yoke (60) 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. Remove gaskets and replace with new
ones (see section 9.4.2), if necessary.
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
bonnet (2).
8. Pull the entire packing out of the packing
chamber using a suitable tool.
We recommend replacing the packing as
well. See section 9.4.3.
9. Make sure that the guide bushing (7) is
not damaged. If necessary, replace the
guide bushing using a suitable tool.
10. Remove the seat (4) and seat retainer
(124).
11.
Remove the gasket (127).
12.
Carefully clean the facings (DF 1, DF 2,
DF 3 and DF 7).
13. Insert a new gasket (127) into the seat
bridge.
14.
Carefully place the new seat (4) in the
body (1) and use the seat retainer (124)
to clamp it into position. Align the seat
retainer in such a way that an opening
faces toward the valve outlet.
15. Insert gaskets (see section 9.4.2).
16. Slide the new plug with plug stem (5) in-
to the bonnet (2).
17. Place the bonnet (2) together with the
plug stem and plug (5) onto the body.
NOTICE
!
NOTICE
!
Note
Summary of Contents for 3291
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Page 30: ...4 6 EB 8072 EN Shipment and on site transport...
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Page 91: ...EB 8072 EN 15 3 Annex...
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