
5.1 Replacing the stuffing box
packing
If leakage occurs at the stuffing box, the
stuffing box packing must be replaced as
described below.
1. For actuators with "Actuator stem ex-
tends", apply approx. 50 % of the sig-
nal pressure range (see nameplate) to
the actuator, causing the actuator stem
to retract.
Place socket wrench (width across flats
(SW) 17) on stem connector nut (7.1)
and unscrew stem connector sleeve
(7.2) with a second SW 17 wrench.
2. Unscrew the bottom slotted round nut
(5.2). Remove actuator (8) including
yoke (6) from the valve, turning the
slotted round nut (5.2), so that a groove
points towards the travel indicator scale
(6.1).
3. Take out the nuts (3). Remove stem con-
nector sleeve (7.2) from the plug stem.
4. Remove the screw (1.1) and the anti-ro-
tation device (2.4). Unscrew the valve
bonnet (5) from the valve body.
5. Unscrew threaded bushing (5.1). Pull
the plug stem, together with the plug
(2.2), out of the valve bonnet (5).
For versions with bellows intermediate
piece or insulating section, separate
valve bonnet and bellows intermediate
piece/insulating section (9). The plug
stem extension (10.1, Fig. 6) remains
fixed in the extension bonnet.
6. Remove packing washers (4.1) and
packing rings (4) from the packing
chamber using a suitable tool. Make
sure not to damage the sealing edges.
Clean packing chamber thoroughly.
Assembly:
7. Insert new sealing rings. Start with a
white ring, followed by two black rings
and another white one. Make sure that
the butt joints of successive rings are
not positioned on top of each other.
8. Insert packing washer(s) (4.1). Tighten
threaded bushing (5.1) manually.
9. Slide plug stem with plug (2.2) into the
valve bonnet as far as it will go. Tighten
threaded bushing (5.1), observing a
minimum gap of 1.3 mm between valve
bonnet and threaded bushing. If this is
not the case, add required number of
packing washers (4.1) (min. 1, max. 3
washers).
10. Insert new sealing ring (2.3) into the
body. Screw together valve bonnet and
body.
11. Place anti-rotation device (2.4) on the
valve bonnet and tighten it, so that the
fastening screw (1.1) is seated in the ob-
long hole.
12. Push stem connector sleeve (7.2) onto
the plug stem with the thread facing up-
wards. Screw on nuts (3).
Lock nuts against each other, so that ap-
prox. 1 mm of the thread is still visible.
13. Place actuator including yoke onto
valve bonnet. Tighten with slotted round
nut (5.2).
For actuators with "Actuator stem ex-
tends", apply approx. 50 % of the sig-
nal pressure range (see nameplate) to
the actuator using a pressure regulator,
causing the actuator stem to retract far
10 EB 8091 EN
Troubleshooting