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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Maintenance and repair
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Maintenance should only be carried out by qualified and authorized persons.
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Observe the maintenance and repair instructions for the individual components.
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Resistance to pressure impact and ignition:
Resistance to pressure impact and ignition is achieved by the use of a sealing system as well as through
component design.
Danger:
In the event of heavily worn or damaged seals the resistance to explosive pressure and ignition are not
guaranteed.
In order to guarantee the resistance to impact pressure and ignition, it is recommended to check the valve once
a year for leaks. Depending on conditions of operation and use a shorter inspection interval can be necessary.
If leaks are found, these must be eliminated as indicated below.
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Danger:
Removal of the protective cover, except for installation, maintenance and / or repair work, is not
permitted. After dismantling the protective cover to carry out installation, maintenance and / or repair work,
attention should be paid to the movable parts of the valve.
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Danger:
Before starting maintenance or repair, ensure that any parts of the valve which may be touched have
cooled to room temperature.
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Danger:
Check whether the pipeline has been rendered depressurized and is empty.
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Danger:
Check whether pneumatic or hydraulic actuators have been rendered depressurized.
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Danger:
Before starting maintenance or repair work, the pneumatic or hydraulic cylinders and the piping system
must be checked for residual energy (e.g. pressure buffer).
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Danger:
Automatic or remotely-operated valves must be disconnected from the automatic operation system or
remote control system for the duration of the maintenance or repair work.
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Danger:
Pneumatic cylinders equipped with an opening or closing spring may only be disassembled at the
factory of the manufacturer. It is important to observe the maintenance and repair instructions.
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Danger:
Maintenance work for parts which are in contact with dangerous materials or liquids should only be
carried out by persons wearing suitable protection clothes.
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Only original spare parts should be used.
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Readjusting the seal:
During prolonged storage and in the event of larger temperature fluctuations, the sealing material of the seal of
the narrow face may shrink or else release air trapped in the seal and thus can cause minor leakages on the
narrow face of the plate. If any leakage is found in the transverse seal in initial operation during the pressure
test or after readjusting the seal (as per the instructions for installation of the block profile transverse seal) or
after a prolonged period of disuse, and this still persists even after operating the valve several times, then the
seal can easily be re-tensioned while the valve is still installed. The valve should not, however, be under full
operating pressure when this work is done.
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Minor leaks:
Minor leaks can be eliminated by tightening the
packing hole screws (A). If this does produce any
significant improvement, remove the packing hole
screws (A) and apply the packing material (B) by
means of the packing tool (C) until the valve is
tight. In the case of valves sealed with a
transverse seal, take care that the packing tool is
pushed into the hole provided in the seal and the
packing material is compressed between the
seals. The packing hole screws (A) should be
tightened up again by about 3 turns.
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Major leaks:
Major leaks are an indication of worn or damaged
seals.
If the leak cannot be eliminated by the packing
method described above,
the valve sealing system must be replaced.
Replacement of the seals is to take place according to the operating instructions "Maintenance / Seal
Replacement Series AT". It is recommended to have the manufacturer carry out the seal replacement.
Danger:
In the event of heavily worn or damaged seals the resistance to explosive pressure and ignition are not
guaranteed.