12 EB 8039 EN
Maintenance
7.2 Assembly (DN
15 to 80)
1. Inthefail-closeversion,placetheplugin
thebody.Inthefail-openversion,push
plug into the valve bonnet. Carefully
degrease the thread of the plug stem.
2. Apply a suitable sealant to the seat and
screw it in using the seat wrench. Ob-
serve tightening torque according to Ta-
ble3.
3. Packing:rstinsertspring(4.1)and
washer(4.3)intothepackingchamber,
thentheV-ringpackingparts(4.2)after
applying lubricant to them. Loosely screw
inthreadedbushing(5.2).
4. Insertgasket(1.2)intothebody.Place
thevalvebonnet(5)onthebody.Inthe
fail-close version, lift the plug stem and
carefully guide it through the packing.
Fasten the valve bonnet by evenly tight-
eningthenuts(1.1).Threadthelocknut
(3.2)ontotheplugstemuntilitreaches
thethreadend.Placeonwasher(3.3).
5. Insertspring(5.5)intothevalvebonnet
andalignitaccordingtoFig.3.Screw
springplate(5.6)ontheplugstemby
hand, until it rests on the spring. Align
the cam of the spring plate cams so that
it is positioned above the recess of the di-
aphragm case.
6. Screw on mounting device. Evenly tight-
en clamping bolts until the spring is pre-
loadedapprox.6mmbythespring
plate.
7. Apply a suitable adhesive to the thread
of the plug stem. Position plug wrench or
hex screwdriver and turn the plug stem
counterclockwise until it reaches the plug.
Continue to gradually tension the mount-
ing device until it rests on the diaphragm
case with its three stop bushings in the
fail-closeversionorapprox.2mmaway
fromitinthefail-openversion.Inthis
position, turn the plug counterclockwise
as far as it will go and tighten the lock
nut(3.2).Removethemountingdevice.
8. Insertdiaphragm(5.4),placediaphragm
case on top and tighten evenly. Tighten
threadedbushing(5.2)asfarasitwill
go.
7.3 Disassembly (DN 100)
1. Remove nuts and bolts at the actuator.
For versions with handwheel, turn the
handwheel to ensure that the spring plate
(7.1)isnolongerundertension.Liftoff
thediaphragmcase(5.7).
2. Loosennut(7.3)andunscrewitwhile
holding the plug stem stationary at the
milled part with an open-end wrench
(widthacrossats14).
3. Remove diaphragm plate and springs.
Unscrewnut(7.2)togetherwithlocknut.
4. Carefullyliftupthevalvebonnet(7).In
the fail-close version, lift it over the plug
stem, and in the fail-open version, lift it
together with the plug stem.
5. To replace the seat and the plug in the
fail-close version, unscrew the seat.
To proceed, position the seat wrench (see
Table2)ontheseatsothatitsrecesses
are aligned with the cams of the seat.
Guide the seat wrench over the plug