Samson 3331/3278, Mounting And Operating Instructions

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3. Fasten yoke (3) with 2 or 4 screws de-
pending on the nominal size of the valve
to the flange of the shaft (4).
4. Slide actuator over shaft (4) and fasten
tight at yoke (3) using the four screws.
5. Undo stop screw (13.1) again.
6. Apply the signal pressure required for
the spring range (see nameplate) to
achieve the closed position.
7. Turn the stop screw (13.1) until the valve
is completely closed.
Align the markings on the shaft with the
markings on the gland flange.
8. Disconnect the signal pressure.
9. Turn the stop screw (13.2) until the disc
(8) reaches the open position (90° or
70° angle of rotation).
10. Secure the position of both stop screws
with their lock nuts.
2.2 Mounting position
The butterfly valve may be installed vertically
or horizontally in the pipeline. However, the
following points must be observed for the di-
rection of flow:
Mount the butterfly valve in the pipeline so
that the lower half of the disc opens towards
the direction of the flow. This helps prevent
any dirt deposits collecting which could pre-
vent the disc from opening.
Butterfly valves with angle-seated/low-noise
(streamlined) discs must be mounted without
exception with the direction of flow indi-
cated by the arrow on the valve body. On
mounting the valve between flanges in the
pipeline, place the disc in its closed position.
Take care not to damage the facings. On
tightening the flange bolts, make sure that
the flat gaskets are compressed evenly.
The butterfly disc must move without any re-
strictions when the valve is installed in the
pipeline.
2.3 Test connection
Butterfly valves with a test connection to
monitor the packing (recognizable by a
label and hexagonal screw plug), must be
equipped with a suitable leakage indicator
such as a contact pressure gauge, outlet into
an open receptacle or sight-glass.
2.4 Loading pressure connection
The loading pressure connection of small ro-
tary actuators is designed as a tapped G 1/8
hole and G 1/4 in large actuators.
Connection according to VDI/VDE 3845 al-
lows also the attachment of solenoid valves
(e.g. Type 3963) or a limit switch with or
without solenoid valve (e.g. Type 3776/
3777).
In conjunction with SAMSON positioners,
suitable accessories are available for connec-
tion.
8
EB 8227 EN
Installation