Samson 3351 - Disassembly (DN 100;NPS 4); Assembly (DN 100;NPS 4)

9-8 EB 8039 EN
Servicing
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.
9.4.3 Disassembly(DN100/
NPS4)
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ats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
the 'Tightening torques, lubricants and
tools' section in the annex of these in-
structions) on the seat so that its recesses
are aligned with the cams of the seat.
Guidetheseatwrenchovertheplug
stem in the fail-close version. Observe
thespeciedtighteningtorque(seethe
'Tightening torques, lubricants and tools'
section in the annex).
Insert the guide part of the seat wrench
into the body and unscrew seat with a
suitable tool extension.
6. Carefullycleanallparts.Removegasket
(1.2). If the packing leaks, unscrew the
threaded bushing (5.2) in the valve bon-
net and pull out the individual parts, e.g.
V-ring packing (4.2), washer (4.3) and
spring (4.1). When replacing the plug,
renew the packing rings (4.2) as well.
Carefullycleanallpartsandthepacking
chamber.
9.4.4 Assembly(DN100/
NPS4)
1. In the fail-close version, place the plug in
the body. In the fail-open version, push
plug into the valve bonnet. Thoroughly
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thespeciedtighteningtorque(see
the 'Tightening torques, lubricants and
tools' section in the annex).
3. Packing:rst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