Samson 3271, Original Instructions Manual, Page: 40 / 72

7-2 EB 8310-6 EN
Operation
must not exceed the upper bench range val-
ue by more than 3 bar:
Bench range
Fail-safe
action
Max. supply
pressure
0.2 to 1.0 bar
Actuator stem
retracts
4 bar
0.4 to 2.0 bar 5 bar
0.6 to 3.0 bar 6 bar
Actuator stem extends (FA)
With direction of action "actuator stem ex-
tends" and travel stop, the supply pressure
must not exceed the upper bench range val-
ue by more than 1.5 bar.
7.3 Manual mode (versions
with handwheel only)
In the manual mode, the valve is opened
and closed by the handwheel. The valve po-
sition is independent of the signal pressure
or actuator springs.
The handwheel must be in the neutral posi-
tion to allow the actuator to move through its
entire travel range in throttling or on/off ser-
vice.
In Type 3271 and Type 3277 Pneumatic Ac-
tuators with 700 cm² actuator area and a
handwheel, the upper bench range value
must not exceed 3.3 bar.
7.4 Additional notes con -
cerning operation
Î
Label actuator with reduced supply pres-
sure with a sticker ("Max. supply pres-
sure limited to ... bar").
Î
Only apply the signal pressure to the sig-
nal pressure connection (S) on the dia-
phragm chamber of the actuator which
does not contain any springs (see
Fig. 3-1 and Fig. 3-2 in the 'Design and
principle of operation' section).
Î
Only use vent plugs that let air through
them (A16 in Fig. 3-1 and Fig. 3-2 in the
'Design and principle of operation' sec-
tion).