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achieved by breaking the vacuum in the
system with OFN and continuing to ll
until the working pressure is achieved,
then venting to atmosphere, and nally
pulling down to a vacuum. This process
shall be repeated until no refrigerant is
within the system. When the nal OFN
charge is used, the system shall be
vented down to atmospheric pressure to
enable work to take place. This operation
is absolutely vital if brazing operations on
the pipework are to take place.
Ensure that the outlet for the vacuum
pump is not close to any ignition sources
and there is ventilation available.
In addition to conventional charging
procedures, the following requirements
shall be followed.
Charging procedures
•
Ensure that contamination of dierent
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
overll 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.
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.
Decommissioning
1.
Become familiar with the equipment
and its operation.
2.
Isolate system electrically.
3.
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.
4.
Pump down refrigerant system,
if possible.
5.
If a vacuum is not possible, make
a manifold so that refrigerant can
be removed from various parts of
the system.
6.
Make sure that cylinder is situated
on the scales before recovery takes
place.
7.
Start the recovery machine and
operate in accordance with
manufacturer's instructions.
8.
Do not overll cylinders. (No more
than 80% volume liquid charge).
9.
Do not exceed the maximum working
pressure of the cylinder, even
temporarily.
10.
When the cylinders have been lled
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 o.
11.
Recovered refrigerant shall not be
charged into another refrigeration
system unless it has been cleaned
and checked.
Equipment shall be labelled stating that it
has been de-commissioned and emptied
of refrigerant. The label shall be dated
and signed. Ensure that there are labels
on the equipment stating the equipment
contains ammable refrigerant.
Labelling
