Samson 3767 Mounting And Operating Instructions - Attachment to Control Valve
2
Attachment to control valve
The positioner is attached either directly to
SAMSON Type 3277 Actuator or to valves
with cast yokes or with rod-type yokes in ac-
cordance with IEC 60534-6 (NAMUR).
When combined with an intermediate piece,
the device can also be attached to rotary ac-
tuators as a rotary positioner. As the
positioner is also available as a basic unit
without accessory equipment, refer to the ta-
bles on the following pages for both the re-
quired mounting parts and their associated
order numbers.
Do not remove the protective cover on the
back of the positioner before actually start-
ing to attach the positioner.
Mounting position and operating direction
The operating direction of the positioner
also determines its mounting position on the
actuator as illustrated in Figs. 3, 4 and 6.
The turnboard (7, Fig. 2) at the positioner
must be mounted correspondingly. For an
increasing input signal (reference variable),
the signal pressure p
st
can either be increas-
ing (direct action >>) or decreasing (reverse
action <>). This also applies when the refer-
ence variable decreases: direct action >>
causes the signal pressure to decrease, re-
verse action <> causes the signal pressure to
increase.
On the turnboard (7), the operating direc-
tion is indicated by symbols (direct >>, re-
verse <>). Depending on the position of the
turnboard, the adjusted operating direction
and the associated symbol become visible.
If the required operating direction does not
correspond to the visible symbol, or if you
want to change the operating direction, re-
move the fastening screw at the turnboard,
turn the board by 180°, and refasten the
turnboard with the screw. Make sure the
three rubber gaskets inserted in the housing
remain in position.
Note:
When any subsequent changes are
made, e.g. reversing the operating direction
of the positioner control loop or changing
the actuator from “Actuator stem extends” to
“Actuator stem retracts” or vice versa, the
positioner's mounting position must be
changed accordingly.
2.1 Direct attachment to Type
3277 Actuator
Required accessories are listed in Tables 1
to 4 on page 14.
The attachment of the positioner either on
the left or right side of the actuator (always
looking at the signal pressure connection or
switchover plate) is determined by the re-
quired operating direction of the positioner,
i.e. >> or <>.
10
EB 8355-2 EN
Attachment to control valve