Samson 3351, Mounting And Operating Instructions

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12 EB 8039 EN
Maintenance
7.2 Assembly (DN 15 to 80)
1. In the fail-close version, place the plug in
the body. In the fail-open version, 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-
ble 3.
3. Packing: first insert spring (4.1) and
washer (4.3) into the packing chamber,
then the V-ring packing parts (4.2) after
applying lubricant to them. Loosely screw
in threaded bushing (5.2).
4. Insert gasket (1.2) into the body. Place
the valve bonnet (5) on the body. In the
fail-close version, lift the plug stem and
carefully guide it through the packing.
Fasten the valve bonnet by evenly tight-
ening the nuts (1.1). Thread the lock nut
(3.2) onto the plug stem until it reaches
the thread end. Place on washer (3.3).
5. Insert spring (5.5) into the valve bonnet
and align it according to Fig. 3. Screw
spring plate (5.6) on the plug stem by
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-
loaded approx. 6 mm by the spring
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-close version or approx. 2 mm away
from it in the fail-open version. In this
position, turn the plug counterclockwise
as far as it will go and tighten the lock
nut (3.2). Remove the mounting device.
8. Insert diaphragm (5.4), place diaphragm
case on top and tighten evenly. Tighten
threaded bushing (5.2) as far as it will
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) is no longer under tension. Lift off
the diaphragm case (5.7).
2. Loosen nut (7.3) and unscrew it while
holding the plug stem stationary at the
milled part with an open-end wrench
(width across flats 14).
3. Remove diaphragm plate and springs.
Unscrew nut (7.2) together with lock nut.
4. Carefully lift up the valve bonnet (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
Table 2) on the seat so that its recesses
are aligned with the cams of the seat.
Guide the seat wrench over the plug