Samson 3310, Монтаж и эксплуатация

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3-4 EB 8222-1 EN
Design and principle of operation
a) Fail-close
When the pressure is relieved from the rota-
ry actuator or the supply air fails, the actua-
tor springs close the valve. The valve opens
opposing the force of the actuator springs
when the signal pressure increases.
b) Fail-open
When the pressure is relieved from the rota-
ry actuator or the supply air fails, the actua-
tor springs open the valve. The valve closes
opposing the force of the actuator springs
when the signal pressure increases.
3.1.2 Double-acting Type DAP
Pneumatic Rotary
Actuator
The double-acting AIR TORQUE Type DAP
Rotary Actuator is not fitted with springs. A
defined final position is not reached when
the supply air fails.
3.2 Versions
Actuators
In these instructions, the preferable combina-
tion with a SAMSON Type 3278 Pneumatic
Rotary Actuator or AIR TORQUE Type SRP/
DAP Pneumatic Rotary Actuator is described.
The pneumatic actuator (with or without
handwheel) can be replaced by an electric
actuator.
3.3 Additional fittings
Bypass and shut-off valves
We recommend installing a shut-off valve
both upstream and downstream of the valve
and installing a bypass line. The bypass en-
sures that the plant does not need to be shut
down for service and repair work on the
valve.
3.4 Valve accessories
The signal pressure connection of the rotary
actuator is designed as a borehole with a
G
1 /
8
female thread for small actuators and
with G ¼ female thread for large actuators.
The connection allows in compliance with
VDE/VDE 3845 guidelines the connection of
a solenoid valve, limit switch or positioner
(see Information Sheet
u
T 8350). Mounting
parts are available for SAMSON valve ac-
cessories. See actuator documentation.