Operating instructions
GEFA / DOMINO valve AT 200F (ATEX II 1D/2DG c)
AT200F-ATEX-Betriebsanleitung (GB).doc (ZA) 21.09.2007
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Electrically-operated valves
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Closing may be done exclusively according to our instructions, as follows:
- only switch off in the closing direction by using a torque switch.
- only switch off in the opening direction by using the path switch,
the torque switch that is there serves as overload protection and must also be closed.
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In the case of freely programmable controllers, the path switch and torque switch must be connected
immediately before the contactor coils. For functional reasons, only self-locking actuators may be used.
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Signal transfer at the path switch and torque switch to switch off the electrical actuator must be done in real
time. Signal chaining via multiple contactors or positioning units causes the drive units to run on and can lead to
the destruction of certain components.
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To avoid any risk of damage to the valve before it is operated electrically for the first time, move the plate by
hand to the middle position and only then operate the valve by means of the actuator.
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Check the phase sequence when connecting the power supply. The path switch and torque switch cannot
operate if the phase sequence is wrong.
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The electrical actuator may not be operated unless the torque and limit switch function correctly. The torque set
at the factory must not be changed. If it is necessary to do this in exceptional cases, only do so after consulting
the manufacturer.
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The heating and thermo-switches must be connected without fail to avoid a buildup of condensation and
overheating of the motor. Follow the special operating instructions of the relevant actuator manufacturer.
Normal operation
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The valve should only be operated by persons who are trained and authorized to do so, and who know the
operating instructions and work accordingly.
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Danger:
It must be guaranteed that the feed flow is free from any foreign bodies that could act as an ignition
source.
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Danger:
Removal of the protective cover, except for installation, maintenance and / or repair work, is not
permitted.
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Danger:
The user has the responsibility for taking care that all risks of accident are avoided by taking suitable
precautions in the danger zone for valves used as inlet valves. (The legal stipulations are to be followed here.)
Before entering the danger area it must be guaranteed that the valve is completely closed (and thus ignition-
proof).
For this reason the valves are generally to be designed with an end position indicator.
Used end position indicators (e.g. limit switch or proximity switch) must have high safety standard against
malfunctions (e.g. switches featuring with positive opening contacts).
Visual control of the gate position must be carried out even if end position is indicated by limit switches.
For this purpose the factory-made marking on the gate can be used. The marking is located on the right side at
the inlet side of the valve. The gate has reached the position “CLOSED” if the line below the arrow is in
alignment with the upper edge of the valve body.
Valves with covered gates have to be equipped with a visual position indicator.
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If the valve is seldom operated, and especially in the case of automatic valves, a test run should be made at
least every 3 months to ensure permanent readiness for use and to avoid deposits from becoming baked on.
