Part No. 30911 Rev. A September 2020
- 36 -
Visair Refrigerated Cabinets
Leak Checking
VISAIR CABINETS
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APPENDIX A
R-290 Refrigerant
Warning
Do NOT use any leak test dyes when working on an R-290 refrigeration system.
Detection
Methods
•
Bubble test.
•
Electronic combustible gas detection.
•
Nitrogen holding pressure test (only possible on accessed systems).
For the most part, you would leak check a R-290 system the same way you
would a R-134a or R-404A system with a couple of exceptions.
You cannot use a halide leak detector on an R-290 system, the electronic leak
detector must be designed specifically for combustible gas.
Using oxygen-free dry nitrogen with a trace gas not exceeding 150PSIG is also
recommended.
Accessing the Refrigeration System
VISAIR CABINETS
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APPENDIX A
R-290 Refrigerant
Installing
Piercing Valves
Line tap valves can be used to access the refrigeration system. Line tap valves
should be temporarily placed on the suction and liquid process tubes.
IMPORTANT:
Never leave piercing valves of any type on the R-290
refrigeration system. This would void the warranty.
Procedure
Make sure the cabinet is disconnected from the power
source.
Wear safety glasses and gloves (rubber coated are
best).
Turn the combustible-gas
leak detector “ON”.
Refer to the manufacturer’s instructions for the
detector you are using.
Post the warning notice in plain view for all to see on
the front and rear of the refrigeration appliance.
Remove the red sleeves on the suction and liquid line
process tubes.
Install the piercing valves following
manufacturer’s
instructions.
Red sleeves must be replaced when done servicing.
