Manual Mode (Versions With Handwheel Only); Additional Notes Concerning Operation - Samson 3372 Mounting And Operating Instructions

Version with direction of action "actuator
stem retracts"
With fail-safe action "actuator stem retracts
(FE)", the permissible supply pressure must
not exceed the upper bench range value by
more than 3 bar:
Bench range
0.2 to 1.0 bar
0.4 to 2.0 bar
0.6 to 3.0 bar
Version with direction of action "actuator
stem extends"
With fail-safe action "actuator stem extends"
and travel stop, the supply pressure must not
exceed the upper signal range value 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.
When the handwheel is placed back into the
neutral position, the actuator returns to throt-
tling or on/off service.
7-2
Max.
Fail-safe
supply
action
pressure
4 bar
Actuator stem
5 bar
retracts
6 bar
7.4 Additional notes con-
cerning operation
Î Label actuators with reduced supply
pressure with a sticker ("Max. supply
pressure 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.
EB 8313-3 EN