Samson 3277, Монтаж и эксплуатация

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EB 8310-5 EN 11
Design and principle of operation
3 Design and principle of oper-
ation
The SAMSON Type 3271 and Type 3277
Actuators with 175 and 750 cm² actuator
areas are mounted to Series 240, 250, 280,
and 290 Valves (globe valves).
3.1 Type 3271
The actuator mainly consists of two dia-
phragm cases (A1, A2), the diaphragm (A4)
with diaphragm plate (A5), and springs
(A10) (see Fig. 2).
The signal pressure p
st
creates the force F =
p
st
· A at the diaphragm surface A which is
opposed by the springs (A10) in the actua-
tor. The bench range is determined by the
number of springs used and their compres-
sion, taking into account the rated travel. The
travel is proportional to the signal pressure
p
st
. The direction of action of the actuator
stem (A7) depends on how the springs are
installed in the actuator.
A maximum of twelve springs, partly fitted
into one another, can be installed in the ac-
tuator.
The stem connector clamps (A26/27) con-
nect the actuator stem (A7) with the plug
stem of the globe valve.
A1 Top diaphragm
case
A2 Bottom diaphragm
case
A4 Diaphragm
A5 Diaphragm plate
A7 Actuator stem
A8 Ring nut
A10 Spring
A16 Vent plug
A26/27 Stem connector
clamp
S Signal pressure
connection
A4
A1
A16
A2
S
A10
A8
A7
A26/27
A5
Fig. 2: Functional diagram of Type 3271 Actuator (175 cm²), "stem extends" direction of action