EN
Leak detection methods
The following leak detection methods are deemed acc
refrigerant systems.
Electronic leak detectors may be used to detect refrigerant leaks but, in
the case of ammable refrigerants, the sensitivity may not be adequate
or may need re-calibration. (Detection equipment shall be calibrated in a
refrigerant-free area.) Ensur
ignition and is suitable for the refrigerant used
shall be set at a percentage of the LFL of the refrigerant and shall be
calibrated to the refrigerant emplo
gas (25 % maximum) is conrmed.
Leak detection uids are suitable for use with most refrigeran
use of detergents containing chlorine shall be av
react with the refrigerant and corrode the copper pipe-work.
If a leak is suspected, all naked ames shall be removed/extinguished.
If a leakage of refrigerant is found which requires brazing, all of the
refrigerant shall be recov
shut o valves) in a part of the system remote from the leak. F
containing ammable refrigerants, o
be purged through the system both bef
Removal and evacua
When breaking into the refrigerant circuit to make r
purpose – conventional proc
refrigerants it is important that best practice is followed since ammability
is a consideration.
• remove refrigeran
• purge the circuit with inert gas;
• evacuate;
• purge again with inert gas;
• open the circuit by cutting or brazing.
The refrigerant charge shall be rec
cylinders. For appliances containing ammable r
shall be
to be repeated several times
for purging refrigeran
For appliances c
achieved by breaking the vacuum in the system with OFN and continuing
to ll until the working pressure is achieved, then v
and nally pulling down to a vacuum.
This process shall be repeat
When the nal OFN charge is used, the system shall be v
to atmospheric pressure to enable w
absolutely vital if brazing operations on the pipe-work are to take place.
Ensure that the outlet of the vacuum pump is not close to any ig
sources and that ventilation is a
Charging procedur
In addition to conventional charg
requirements shall be follo
• Ensure that contamination of dier
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 alr
• Extreme care shall be taken not to overll the operefrigeration system.
Prior to recharg
appropriate purging gas.
The system shall be leak-tested on c
commissioning. A follow up leak t
the site.
Decommissioning
Before carrying out this procedure, it is essential that the t
is completely familiar with the equipment and all its detail. It is
recommended good practice that all refrigerants ar
Prior to the task being carried out, an oil and refrigerant sample shall be
taken in case analysis is required prior to reuse of r
essential that electrical power is available befor
a. Become familiar with the equipment and its operation.
b. Isolate system electrically.
c. Before attempting the proc
mechanical handling equipment is available, if required, for handling
refrigerant cylinders;
all personal protective equipment is available and being used
correctly;
the recovery process is supervised at all times by a competent
person;
recovery equipment and c
standards.
d. Pump down refrigerant syst
e. If a vacuum is not possible, make a manifold so that refrigerant can be
removed from various parts of the system.
f. Make sure that cylinder is situated on the scales before reco
place.
g. Star
manufacturer's instructions.
h. Do not overll cylinders. (No more than 80 % volume liquid charge).
i. Do not exceed the maximum working pressure of the cylinder
temporarily
j. When the cylinders have been lled correctly and the process
completed, make sure that the cylinders and the equipment are
removed from sit
are closed o
k. Recovered refrigerant shall not be charged in
system unless it has been cleaned and checked.
Labelling
Equipment shall be labelled stating that it has been decommissioned and
emptied of refrigerant.
containing ammable refrigerants, ensur
equipment stating the equipment contains ammable refrigerant.
Recov
When removing refrigerant fr
decommissioning, it is recommended good pr
are removed saf
When transferring refrigerant into cylinders, ensur
refrigerant recov
number of cylinders for holding the total system charge are av
All cylinders to be used are designated for the rec
and labelled for that refrigerant (i.e
refrigerant). Cylinders shall be complet
associated shut-o valves in good working order
are evacuated and, if possible
The recovery equipment shall be in good working order with a set of
instructions concerning the equipment that is at hand and shall be suitable
for the recov
ammable refrigerants. In addition, a set of calibrated weighing scales
shall be available and in good working order
with leak-free disconnect couplings and in good condition. Befor
the recovery machine, check that it is in satisfactory working order
been properly maintained and that any associated electrical components
are sealed to prevent ig
manufacturer if in doubt.
The recover
in the correct recovery cylinder
arranged. Do not mix refrigerants in reco
cylinders.
If compressors or compressor oils are to be r
been evacuated to an acceptable lev
refrigerant does not remain within the lubricant.
