IM2023
50
Make sure that the seals or sealing materials are not worn to such an extent that they
no longer prevent the passage of flammable substances. Spare parts shall comply with
the manufacturer's specifications.
NOTE: The use of silicone sealant can reduce the effectiveness of some types of leak
detection equipment. Intrinsically safe components do not have to be isolated before
working on them.
11. Maintenance of intrinsically safe components
Before applying permanent inductive or capacitive loads to the circuit, ensure that they
do not exceed the permissible voltage and current allowed for the equipment.
Structurally intrinsically safe components shall be the only type of equipment that can
be operated under voltage in case of a flammable atmosphere. The test equipment
shall be of the appropriate class.
The components shall only be replaced with the parts specified by the manufacturer.
Other parts may ignite the cooling agent in the atmosphere due to its leakage.
12. Wiring
Make sure the cables are not exposed to wear, corrosion, overpressure, vibration,
damage due to contact with sharp edges, or any other adverse environmental effects.
Take into account also the effects of wear from physical obsolescence or constant
vibration from such sources as compressors or air fans.
13. Flammable cooling agents leak detection
Do not use appliances that can be a potential source of ignition when searching for or
detecting cooling agent leaks under any circumstances. The use of halogen leak
detectors (or any other means of open flame detection) is prohibited.
14. Leak detection methods
The following leak detection methods shall be considered as acceptable for systems
containing highly flammable cooling agents.
In order to detect flammable cooling agents, use electronic leak detectors, however,
the sensitivity may be insufficient or recalibration may be required (the detection
equipment shall be calibrated in a cooling agent-free area.) Make sure that the detector
cannot serve as a potential source of ignition and is suitable for the used cooling agent.
Leak detection fluids are suitable for application with most cooling agents, however,
the use of detergents containing chlorine shall be avoided, as the chlorine may react
with cooling agent and corrode the copper piping.
In case of leakage, remove / extinguish all open flame sources.
All the cooling agents shall be removed from the system in case of necessity of
soldering, due to the existence of cooling agent leakage. The oxygen-free nitrogen
(OFN) shall then be purged through the system both before and during the soldering
process.
15. Removal and vacuuming
The usual procedures shall be followed when interfering with the cooling agent circuit
to carry out repairs or for any other purpose. It is necessary to take into account the
flammability of the cooling agent when performing these procedures.
Carry out the following procedures:
Remove the cooling agent;
Purge the circuit with an inert gas;
Pump out the gas;
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