Samson EB 8315 EN, Инструкция по монтажу и эксплуатации

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EB 8315 EN 3-1
Design and principle of operation
3 Design and principle of operation
The Type 3379 Pneumatic Actuators with
spring-return mechanism are used in con-
junction with a valve as a control unit suit-
able for the food and pharmaceutical indus-
tries.
The signal pressure p
st
creates a force on the
piston surface (5) which is counteracted by
the spring(s) (4). The bench range is deter-
mined by the number of springs used and
their compression, taking into account the
rated travel.
The actuators are designed for a maximum
travel of 15 mm. A spring compression is
only possible with smaller travels.
The travel H is proportional to the signal
pressure p
st
. The direction of action of the ac-
tuator stem depends on how the springs are
installed in the actuator.
The supply air is connected for both operat-
ing directions to the top connecting plate.
10
9
8
3
3
1 1
5
2
4
7
6
10
9
8
3
1
5
2
4
7
6
1 Pressure connection to control the
actuator
2 Piston seal
3 Vent plug
4 Spring(s)
5 Piston
6 Base
7 Actuator stem
8 Cover
9 Position indicator (valve OPEN/
CLOSED)
10 Dome (visual indicator)
Actuator stem
retracts (fail-open)
Actuator stem
extends (fail-close)
Actuator stem
extends (fail-close)
Fig. 3-1: Sectional drawings of Type 3379