Samson 3222/2780 series, Монтаж и эксплуатация

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12 EB 5866 EN
Design and principle of operation
3 Design and principle of oper-
ation
The medium flows through the single-seated
globe valve in the direction indicated by the
arrow. The position of the plug determines
the flow rate across the area released be-
tween plug (1) and seat (5). The valve is
opened by the valve spring when the actua-
tor stem retracts. The plug is moved by
changing the control signal applied to the
actuator. The valve and actuator have a
force-locking connection.
A special version (see Fig. 4) is available for
water above 150 °C and steam.
3.1 Fail-safe action
When the Type 3222 Valve is combined with
one of the following actuators, the valve
moves to the fail-safe position up upon fail-
ure of the air supply or power supply:
−
Type 5825 Electric Actuator
−
TROVIS 5725-3 and TROVIS 5725-7
Electric Actuators with Process Control-
lers
− Type 2780 Pneumatic Actuator
The control valve has two different fail-safe
positions:
− Actuator stem extends: upon power sup-
ply or air supply failure, the actuator
stem extends.
The TROVIS 5725-3, TROVIS 5725-7, and
TROVIS 8725-8 Electric Actuators with Pro-
cess Controllers in the version with
force-locking attachment and the Type 5825
Electric Actuator with "actuator stem ex-
tends" fail-safe action are tested by the Ger-
man technical surveillance association TÜV
according to DIN EN 14597 in combination
with the SAMSON Type 3222 Valve. The
registration number is available on request.
−
Actuator stem retracts: upon power sup-
ply or air supply failure, the actuator
stem retracts.
The fail-safe action of pneumatic actuators
can be reversed (see associated actuator
documentation). The fail-safe action of elec-
tric actuators (with process controllers) is al-
ready determined at the ordering stage.
Note
Note