Samson 3767 - Page 31

EB 8355-2 EN 5-7
Installation
Air purging of the spring chamber
If the spring chamber of the actuator is to be
purged with the exhaust air from the posi-
tioner, use piping ( ) to connect the spring
chamber (with "actuator stem extends" ver-
sion) to the connection block. To do so, re-
move the stopper from the connection block.
For an actuator with fail-safe action "actua-
torstemretracts"andinType3277-5Actua-
tors with an effective diaphragm area of
120cm²,theexhaustairfromthepositioner
is connected to the actuator chamber over
an internal hole.
Spring Screw plug
Fig.5-4: Installing the spring on the back of
the housing
5.3.2 Attachment according to
IEC60534-6
The rated travel of the valve determines
which lever and range spring (see Table 5-1)
are required.
An adapter housing is used for attachment
(Fig.5-6). The valve travel is transmitted by
the lever (1) and the shaft (8) to the bracket
(11) of the adapter housing and then passed
on to the pin (10a) on the lever of the posi-
tioner. To ensure that the pin (10a) is proper-
Left attachment Right attachment
Mounting position on the plate looking onto the travel pick-off (20), actuator facing upward (see also
Fig.5-6)
Actuator with “actuator stem extends” (FA) fail-safe action
Operatingdirection>> Operatingdirection<> Operatingdirection>> Operatingdirection<>
20
Output and supply InputInput
Actuator with “actuator stem retracts” (FE) fail-safe action
Operatingdirection>> Operatingdirection<> Operatingdirection>> Operatingdirection<>
20
Output and supply Output and supplyInput
Fig.5-5: Attachment to the left or right of the valve for NAMUR attachment (IEC60534-6)
Table 5-1: Travel table
Travel [mm]
1)
7.5 15 15 30 30 60 30 60 60 120
Pin at marking
1)
1 2 1 2 1 2 1 2 1 2
Distance between pin and lever
fulcrum
42to84mm 84to168mm
With lever N1(125mmlong) N2(212mmlong)
Pin(27a)atposition A A B A B
Required range spring (see
section5.8)
2 1 1 1 1
1)
Calculate intermediate values