Samson 3253, Перевод оригинальной инструкции

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EB 8055 EN 3-3
Design and principle of operation
Actuator stem extends (FA)
When the signal pressure is reduced or the
air supply fails, the springs move the actua -
tor stem downward. In mixing valves, port B
is closed. In diverting valves, port A is
closed. The valve ports B or A respectively
are opened against the force of the compres -
sion springs when the signal pressure in -
creases.
Actuator stem retracts (FE)
When the signal pressure is reduced or the
air supply fails, the springs move the actua -
tor stem upward. In mixing valves, port B is
opened. In diverting valves, port A is
opened. The valve ports B or A respectively
are closed against the force of the compres -
sion springs when the signal pressure in -
creases.
The actuator's direction of action can be re-
versed, if required. Refer to the mounting
and operating instructions of the pneumatic
actuator:
u
EB 8310-X for Type 3271 and Type 3277
3.2 Versions
With insulating section/bellows seal
The modular design allows an insulating sec -
tion or bellows seal to be fitted to the stan-
dard valve version.
Actuators
In these instructions, the preferable combina -
tion with a SAMSON Type 3271 or
Type 3277 Pneumatic Actuator is described.
The pneumatic actuator (with or without
handwheel) can be replaced by another
pneumatic actuator in a different size, but
with the same travel.
Î
Observe the maximum permissible actu-
ator force.
If the travel range of the actuator is larger
than the travel range of the valve, the spring
assembly in the actuator must be preloaded
so that the travel ranges match. See associ -
ated actuator documentation.
The basic pneumatic actuator can be re -
placed by a pneumatic actuator with addi -
tional handwheel or by an electric actuator
(see Information Sheet
u
T 8300).
Anti-rotation fixture
The valve in valve sizes DN 50 and larger is
fitted with an anti-rotation fixture. It is mount-
ed to the actuator/plug stem to protect the
plug against damage caused by rotation.
3.3 Additional fittings
Strainers
We recommend installing a SAMSON
strainer upstream of the valve. We recom-
mend installing a strainer upstream of both
valve inlet ports in mixing valves. It prevents
solid particles in the process medium from
damaging the valve.
Tip
Note