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8 9
NOTE: The use of silicon sealant may inhibit the effectiveness of some types of leak
detection equipment. Intrinsically safe components do not have to be isolated prior to
working on them.
2. REPAIR TO INTRINSICALLY SAFE COMPONENTS
Do not apply any permanent inductive or capacitance loads to the circuit without ensuring that
this will not exceed the permissible voltage and current permitted for the equipment in use.
Intrinsically safe components are the only types that can be worked on while live in the
presence of a flammable atmosphere. The test apparatus shall be at the correct rating. Replace
components only with parts specified by the manufacturer. Other parts may result in the ignition
of refrigerant in the atmosphere from a leak.
3. CABLING
Check that cabling will not be subject to wear, corrosion, excessive pressure, vibration, sharp
edges or any other adverse environmental effects. The check shall also take into account the
effects of aging or continual vibration from sources such as compressors or fans.
4. DETECTION OF FLAMMABLE REFRIGERANTS
Under no circumstances shall potential sources of ignition be used in the searching for or
detection of refrigerant leaks. A halide torch (or any other detector using a naked flame)
shall not be used.
5. REMOVAL AND EVACUATION
When breaking into the refrigerant circuit to make repairs – or for any other purpose –
conventional procedures shall be used. However, it is important that best practice is followed
since flammability is a consideration. The following procedure shall be adhered to: safely remove
refrigerant following local and national regulations; purge the circuit with inert gas; evacuate;
purge again with inert gas; open the circuit by cutting or brazing.
6. 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.
7. DECOMMISSIONING
Before carrying out this procedure, it is essential that the technician is completely familiar
with the equipment and all its detail. It is recommended good practice that all refrigerants are
recovered safely. Prior to the task being carried out, an oil and refrigerant sample shall be taken
in case analysis is required prior to re-use of reclaimed refrigerant. It is essential that electrical
power is available before the task is commenced.
• Become familiar with the equipment and its operation.
• Isolate system electrically.
• Before attempting the procedure ensure that :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 cylinders conform to the appropriate standards.
• Pump down refrigerant system, if possible.
• If a vacuum is not possible, make a manifold so that refrigerant can be removed from various
parts of the system.
• Make sure that cylinder is situated on the scales before recovery takes place.
• Start the recovery machine and operate in accordance with manufacturer’s instructions.
• Do not overfill cylinders. (No more than 80% volume liquid charge).
• Do not exceed the maximum working pressure of the cylinder, even temporarily.
• When the cylinders have been filled correctly and the process completed, make sure that the
cylinders and the equipment are removed from site promptly and all isolation valves on the
equipment are closed off.
• Recovered refrigerant shall not be charged into another refrigeration system unless it has been
cleaned and checked.
8. LABELING
Equipment shall be labelled stating that it has been decommissioned and emptied of refrigerant.
The label shall be dated and signed.
Ensure that there are labels on the equipment stating the equipment contains flammable
refrigerant.
9. RECOVERY
When removing refrigerant from a system, either for servicing or decommissioning, it is
recommended good practice that all refrigerants are removed safely. When transferring
refrigerant into cylinders, ensure that only appropriate refrigerant recovery cylinders are
employed. Ensure that the correct number of cylinders for holding the total system charge are
available. All cylinders to be used are designated for the recovered refrigerant and labelled for
that refrigerant (i.e. special cylinders for the recovery of refrigerant). Cylinders shall be complete
with pressure relief valve and associated shut-off valves in good working order. Empty recovery
cylinders are evacuated and, if possible, cooled before recovery occurs.
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 recovery of flammable refrigerants.In
addition,a set of calibrated weighing scales shall be available and in good working order. Hoses
shall be complete with leak-free disconnect couplings and in good condition. Before using the
recovery machine, check that it is in satisfactory working order, has been properly maintained
and that any associated electrical components are sealed to prevent ignition in the event
of a refrigerant release. Consult manufacturer if in doubt.
The recovered refrigerant shall be returned to the refrigerant supplier in the correct recovery
cylinder, and the relevant Waste Transfer Note arranged. Do not mix refrigerants in recovery units
and especially not in cylinders.
If compressors or compressor oils are to be removed, ensure that they have been evacuated to an
acceptable level to make certain that flammable refrigerant does not remain within the lubricant.
The evacuation process shall be carried out prior to returning the compressor to the suppliers.
Only electric heating to the compressor body shall be employed to accelerate this process. When
oil is drained from a system, it shall be carried out safely.
GENERAL INSTRUCTIONS
Checks to the area
Prior to beginning work on systems containing flammable refrigerants, safety checks are
necessary to ensure that the risk of ignition is minimised. For repair to the refrigerating system,
the following precautions shall be complied with prior to con-ducting work on the system.
Work procedure
Work shall be undertaken under a controlled procedure so as to minimise the risk
of a flammable gas or vapour being present while the work is being performed.
General work area
All maintenance staff and others working in the local area shall be instructed on the nature of
work being carried out. Work in confined spaces shall be avoided.The area around the workspace
shall be sectioned off. Ensure that the conditions within the area have been made safe by control
of flammable material.
Checking for presence of refrigerant
The area shall be checked with an appropriate refrigerant detector prior to and during work,
to ensure the technician is aware of potentially flammable atmospheres. Ensure that the leak
detection equipment being used is suitable for use with flammable refrigerants, i.e. nonsparking,
adequately sealed or intrinsically safe.
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