Manual Mode (Versions With Handwheel Only); Additional Notes Concerning Operation - Samson 3271 Mounting And Operating Instructions

Operation
Actuator stem retracts (FE)
For the direction of action "actuator stem re-
tracts", the permissible supply pressure must
not exceed the upper bench range value by
more than 3 bar:
Rated signal
range
0.2 to 1.0 bar
0.4 to 2.0 bar
0.6 to 3.0 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.
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").
7-2
Max.
Fail-safe
supply
action
pressure
4 bar
Actuator stem
5 bar
retracts
6 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 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).
EB 8310-4 EN