Samson 3780 series, Монтаж и эксплуатация

Страница: 24 / 76

2.3.3 Aligning and mounting of
the cam disk
In rotary actuators with spring-return mech-
anism, the built-in actuator springs deter-
mine the fail-safe position and the direction
of rotation of the control valve (either
counterclockwise or clockwise).
With double acting, springless rotary actua-
tors, the direction of rotation depends on
both the actuator and the valve model used.
Any adjustments are only permitted when
the valve has been closed.
The direction of action of the positioner, i.e.
whether the valve shall either open or close
when the reference variable increases, has
to be software-adjusted via the communica-
tion (increasing/increasing or increas-
ing/decreasing direction of action).
1. Position the cam disk with the scale on
the adapter (36) or the coupling (44)
and fasten the screw loosely at first.
The cam disk carries two cam sections. The
starting point of each section is marked by
a small bore.
Note!
With the valve closed, the starting point
(bore hole) of the respective characteristic is
to be aligned so that the center of rotation
of the cam disk, the 0° position on the
scale, and the arrow mark on the disk are
aligned.
The starting point when the valve is closed
should not under any circumstances be
below the 0° position!
With actuators with fail-safe position "Valve
OPEN", the maximum signal pressure must
be applied to the actuator before aligning
the cam disk.
With springless actuators, the supply air
must be connected.
2. In aligning the cam disk, clip on the
double-sided scaled disk in such a way
that the valve on the scale will corre-
spond to the direction of rotation of the
control valve. Only then, secure the
cam disk with the fastening screws.
Securing the aligned cam disk
If the cam disk should be additionally se-
cured to prevent it from being turned, pro-
ceed as follows:
Choose one of the four bore holes located
centrically around the center bore on the
cam disk which is suitable to secure the cam
disk.
Drill a hole in the adapter (36) or coupling
(44) through the selected hole so that a
2 mm dowel pin can be inserted in this hole.
3. Attach the positioner to the intermediate
piece (34) so that the lever (35) contacts
the cam disk with its cam follower roll.
To do so, insert a 2.5 mm hexagon
socket key or a screw driver from the
front into the bore hole which can be
seen below an oblong hole on the cover
plate and bring the positioner lever in
the required position.
4. Screw the positioner onto the intermedi-
ate piece.
24
EB 8380-1 EN
Attachment to the control valve
All manuals and user guides at all-guides.com