The final test will be the refrigerant line pressure
test. One method is low pressure at 175 PSI
Nitrogen, a few ounces of refrigerant, and leak
detection hardware. Another method is only
with high pressure Nitrogen. High pressure
method is used at the factory up to 600 PSI
Nitrogen for One Hour with thermo graphic tools,
point sensors, visual inspection (safety pressure
impact attire must be worn on this test). On the
field, the low pressure test is preferred. For low
pressure and visual inspection, liquid detergent
soap can be used to check for bubbles on all
joints. If there are bubbles, a leak has been
discovered. If a leak has been identified on a
joint, use soft solder to seal it.
