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Service notes
10. Detection of flammable refrigerants
Under no circumstances should potential ignition sources be used to search for or detect refrigerant leaks. Do not use gas burners
(or other detectors that use exposed flame).
11. Leak detection methods
The following leak detection methods are considered to be suitable for systems containing flammable refrigerants.
For flammable refrigerants use electronic leak detectors. Please note that they may not have sufficient sensitivity or require
calibration. (The equipment should be calibrated where the refrigerant is not present.) Make sure that the detector is not a potential
ignition source and that it is suitable for the type of coolant used. The leak detection device should be set to a fraction of the lower
refrigerant explosion limit and calibrated for the specific refrigerant, and the correct gas concentration (maximum 25%) must be
confirmed.
Leak detection fluids are suitable for most types of refrigerants. However, the use of chlorine-containing detergents should be
avoided as they may react with the coolant and cause corrosion to the copper pipes. In the event of a suspected leak, remove /
extinguish all open flame sources.
If a leak requiring brazing is detected, recover all of the coolant from the system or ensure its isolation (using shut-off valves) in
the section of the system away from the source of the leak. Flush the system with anaerobic nitrogen during and before brazing..
12. Emptying and disposal
If the refrigeration system needs to be opened for repairs - or for other purposes - standard procedures should be followed. The
following procedure should be followed:
a. Remove coolant; b. Blow out the system with inert gas; c. Drain;
d. Blow again with inert gas; e. Open the system by cutting or brazing.
The coolant should be placed in the correct bottles for the recovered coolant. The system should be purged with oxygen-free
nitrogen (OFN) to ensure device safety. You may need to repeat this procedure several times. Do not use compressed air or oxygen
for this purpose.
Purge consists in introducing anaerobic nitrogen into the system in which there is negative pressure and further filling until the
operating pressure is reached, followed by venting and obtaining negative pressure. The above procedure should be repeated until
the system is completely drained of the coolant. After the last anaerobic nitrogen purge, the system must be vented to atmospheric
pressure to allow further work to be carried out. The above step is necessary before brazing the pipes.
Ensure that the pump outlet is not close to ignition sources and that ventilation is provided.
13. Filling procedures
In addition to conventional coolant filling procedures, the following requirements should be observed.
a. Ensure that there is no contamination with other refrigerants when using refrigerant delivery equipment. Hoses and pipes should
be as short as possible to minimize the amount of coolant introduced into them. Gas cylinders must be stored upright.
b. Ensure that the system is grounded before filling the system with coolant.
c. After filling the system, label it (if not done before).
d. Be careful not to introduce too much coolant into the refrigeration system.
e. Before refilling the system, test for leaks using anaerobic nitrogen. After filling, but before putting into service, the system should
be tested for leakage. Before leaving the installation site, carry out a leakage test.
14. Decommissioning
Before performing the procedure, it is necessary for the technician to become fully acquainted with the device. Safe disposal of all
refrigerants is recommended. Before performing the procedure, a sample of oil and refrigerant should be taken in case it is
necessary to analyze it before using the recovered refrigerant again. It is important to check the availability of electrical power
before starting the procedure.
a. Familiarize yourself with the device and its operation.
b. Isolate the system electrically.
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