Samson 3725 series Mounting And Operating Instructions - page 18
Actuators with 240 to 700 cm²
The positioner can be mounted either on the
left or right side of the yoke. The signal pres-
sure is routed to the actuator over the con-
nection block (12), for actuators with
fail-safe action "Actuator stem extends" in-
ternally through a bore in the valve yoke
and for "Actuator stem retracts" through ex-
ternal piping.
1. Place follower clamp (3) on the actuator
stem, align it and screw tight so that the
mounting screw is located in the groove
of the actuator stem.
2. For actuators 240 and 350 cm² with
15 mm travel, keep the follower pin (2)
in pin position 35.
For actuators with 355 or 700 cm², re-
move the follower pin (2) at lever M (1)
on the back of the positioner from pin
position 35, reposition it in the bore for
pin position 50 and screw tight.
3. Insert formed seal (15) in the groove of
the positioner housing.
4. Place positioner on the actuator in such
a manner that the follower pin (2) rests
on top of the follower clamp (3). During
which, press on the ribbed area to lock
the pick-up lever in the top position
(Fig. 9).
The lever (1) must rest on the follower
clamp with spring force.
Mount the positioner on the actuator us-
ing the two mounting screws.
5. Make sure that the tip of the gasket (16)
projecting from the side of the connec-
tion block (12) is positioned above the
actuator symbol that corresponds with
the actuator with fail-safe action "Actua-
tor stem extends" or "Actuator stem re-
tracts". If necessary, remove the three
mounting screws and the cover. Then re-
position the gasket (16) turned by 180°.
6. Place the connection block (12) with the
associated seal rings against the
positioner and the actuator yoke and
fasten using the screw (12.1).
For actuators with fail-safe action "Actu-
ator stem retracts", additionally remove
the stopper (12.2) and fit on the external
signal pressure piping.
7. Mount cover (11) on the other side.
Make sure that the vent plug points
downwards when the control valve is in-
stalled to allow any condensed water
that collects to drain off.
18
EB 8394 EN
Attachment to the control valve – Mounting parts and accessories