5-16. Leak Checking.
a. Connect a pressure gauge to the suction service valve and a
cylinder of refrigerant (item 21,table D-1) to the discharge
service valve. Open both service valves and the cylinder shutoff
valve. Let refrigerant flow into the system until the pressure
gauge indicate 50 psig (3.5 kg/cm 2). Close cylinder shutoff
valve and discharge service valve and disconnect the refrigerant
Connect a cylinder of dry nitrogen (item 8,table D-1) to the dis-
charge service valve.
Open the cylinder shutoff valve and the
discharge service valve and pressurize the system to 350 psig
(22 kg/cm 2).
Close all three valves and test for leaks, using an
electronic leak detector or the soap bubble method as described
The electronic leak detector is sensitive to the presence of
refrigerant gas (Table D-1, Item 1) in the atmosphere. When refrigerant
gas is present in the atmosphere of the work area, false indications
can result. Use in a well ventilated but draft-free area.