Samson 3725 series, Mounting And Operating Instructions

Page: 18 / 68

18 EB 8394 EN
Mounting the positioner
4.3.2 Type 3277 Actuator
Î
Required mounting parts and accesso -
ries: Table 3 on page 29.
Î
Observe travel tables on page 13.
Actuators with 240 to 700 cm² effective ar-
eas
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" internal
-
ly through a hole in the valve yoke and for
"actuator stem retracts" through an external
pipe.
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.
1.
For actuators 240 and 350 cm² with
15 mm travel, keep the pin (2) in pin po
-
sition 35.
For actuators with 355 or 700 cm², re -
move the pin (2) on M lever (1) on the
back of the positioner from pin position
35, reposition it in the hole for pin posi
-
tion 50 and fasten tight.
2. Insert formed seal (15) in the groove of
the positioner housing.
3. Place positioner on the actuator in such a
manner that the pin (2) rests on top of
the follower clamp (3).
4. While doing this, press on the ribbed ar -
ea to lock the lever in the top position
(see Fig. 3).
The lever (1) must rest on the follower
clamp with spring force.
Fasten the positioner on the actuator us-
ing the two fixing screws.
5. Make sure that the tip of the gasket (16)
projecting from the side of the connec
-
tion block is positioned to match the ac -
tuator symbol for the actuator's fail-safe
action "actuator stem extends" or "actua-
tor stem retracts". If this is not the case,
unscrew the three fastening screws and
lift off the cover. Turn the gasket (16) by
180° and re-insert it.
6. Place the connection block (12) with the
associated seals against the positioner
and the actuator yoke and fasten using
the screw (12.1).
7. For actuators with fail-safe action "Actu -
ator stem retracts", additionally remove
the stopper (12.2) and mount the exter
-
nal signal pressure pipe.
8. Mount cover (11) on the other side.
Make sure that the vent plug is located at
the bottom when the control valve is in-
stalled to allow any condensed water
that collects to drain off (see Fig. 5 on
page 16).