DiversiTech International Ltd.
Glaisdale Drive East, NG8 4LY
Nottingham United Kingdom
Email sales@pumph.co.uk
Phone +44(0)115 900 5858
9
FOR FURTHER INSTALLATION ADVICE PLEASE CALL THE TECHNICAL SUPPORT HELPLINE ON 0115 900 5858.
10. Detection of ammable 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 ame) shall not be used.
11. Leak detection methods
The following leak detection methods are deemed acceptable for systems containing ammable refrigerants.
Electronic leak detectors shall be used to detect ammable refrigerants, but the sensitivity may not be adequate,
or may need re-calibration. (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 conrmed. Leak detection uids 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. 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 recovered
from the system, or isolated (by means of shut off valves) in a part of the system remote from the leak. Oxygen
free nitrogen (OFN) shall then be purged through the system both before and during the brazing process.
12. 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 ammability is a consideration. The following
procedure shall be adhered to:
Remove refrigerant; Purge the circuit with inert gas; Evacuate; Purge again with inert gas; Open the circuit by
cutting or brazing.
The refrigerant charge shall be recovered into the correct recovery cylinders. The system shall be ushed with
OFN to render the unit safe. This process may need to be repeated several times. Compressed air or oxygen
shall not be used for this task. Flushing shall be 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 pipe-work are to take place. Ensure that the outlet for the vacuum
pump is not close to any ignition sources and there is ventilation available.
13. 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 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.
14. 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.
WARNING
FOR USING R32/R290 REFRIGERANT
PAC-H-12
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