Samson 3351, Mounting And Operating Instructions

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EB 8039 EN 13
Maintenance
stem in the fail-close version. Observe
tightening torque according to Table 3.
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.
7.4 Assembly (DN 100)
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. Screw nut and lock nut onto the plug
stem according to the dimension R (see
Fig. 1) and tighten. On doing so, make
sure the plug rests on the seat.
6. Insert springs into the valve bonnet.
Align the end of the springs towards the
middle.
7. Place diaphragm plate on the end of the
plug stem (3.1), while pulling the plug
stem as far as it will possibly go out of
the valve. Screw nut (7.3) on tight, while
holding the plug stem stationary at the
milled part with an open wrench (width
across flats 14).
8. Align the holes in the diaphragm, place
diaphragm case on top and fasten tight
by tightening the screws (5.9) evenly.
7.5 Function testing
After reassembling the valve, check whether
the valve functions properly.
Î
Connect a suitable source of compressed
air to the signal pressure connection
(5.8) on the diaphragm actuator.
Fail-close version
− The valve must be completely closed at a
control pressure of 0 bar.
−
The valve must start to open at 3 bar at
the latest.
−
The valve must be completely open at
6 bar.