Royal Sovereign ARP-2214P Manual page 16

6. LEAK DETECTION METHODS
The following leak detection methods are deemed acceptable for systems containing
flammable refrigerants. Electronic leak detectors shall be used to detect flammable refrigerants, but the
sensitivity may not be adequate, or may need recalibration. (Detection equipment shall be calibrated in a
refrigerant-free area.) Ensure that the detector is not a potential source of ignition and is suitable for the
refrigerant used. Leak detection equipment shall be set at a percentage of the LFL of the refrigerant and shall be
calibrated to the refrigerant employed and the appropriate percentage of gas (25 % maximum) is confirmed.
Leak detection fluids are suitable for use with most refrigerants but the use of detergents containing chlorine
shall be avoided as the chlorine may react with the refrigerant and corrode the copper pipe-work.
NOTE : Examples of leak detection fluids are
– bubble method,
– fluorescent method agents.
If a leak is suspected, all naked flames shall be removed/extinguished. If a leakage of refrigerant is found which
requires brazing, all of the refrigerant shall be recovered from the system, or isolated (by means of shut off
valves) in a part of the system remote from the leak. Removal of refrigerant shall be according to 7 removal and
evacuation.
7. REMOVAL AND EVACUATION
When breaking into the refrigerant circuit to make repairs – or for any other purpose – conventional procedures
shall be used. However, for flammable refrigerants it is important that best practice be followed, since
flammability is a consideration. The following procedure shall be adhered to:
a) safely remove refrigerant following local and national regulations.
b) purge the circuit with inert gas.
c) evacuate. (optional for A2L)
d) purge with inert gas. (optional for A2L)
e) open the circuit by cutting or brazing.
The refrigerant charge shall be recovered into the correct recovery cylinders if venting is not allowed by
local and national codes. For appliances containing flammable refrigerants, the system shall be purged with
oxygen-free nitrogen to render the appliance safe for flammable refrigerants. This process might need to be
repeated several times. Compressed air or oxygen shall not be used for purging refrigerant systems.
For appliances containing flammable refrigerants, refrigerants purging shall be achieved by breaking the
vacuum in the system with oxygen-free nitrogen and continuing to fill until the working pressure is achieved,
then venting to atmosphere, and finally pulling down to a vacuum (optional for A2L). This process shall be
repeated until no refrigerant is within the system (optional for A2L). When the final oxygen-free nitrogen charge
is used, the system shall be vented down to atmospheric pressure to enable work to take place.Ensure that the
outlet for the vacuum pump is not close to any ignition sources and there is ventilation available.
8. CHARGING PROCEDURES
In addition to conventional charging procedures, the following requirements shall be followed.
- Ensure that contamination of different refrigerants does not occur when using charging equipment. Hoses or
lines shall be as short as possible to minimise the amount of refrigerant contained in them.
- Cylinders shall be kept upright.
- Ensure that the refrigeration system is earthed prior to charging the system with refrigerant.
- Label the system when charging is complete (if not already).
- Extreme care shall be taken not to overfill the refrigeration system.
Prior to recharging the system it shall be pressure tested with OFN. The system shall be leak tested on
completion of charging but prior to commissioning. A follow up leak test shall be carried out prior to leaving
the site.
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ARP-2214P