5-13. DISCHARGING THE REFRIGERANT (cont.).
c. Remove caps from discharge (4) and suction (5) service valves.
d. Install changing manifold hoses to air conditioner service valves.
In accordance with Environmental Protection Agency regulations refrigerants cannot be
discharged into the atmosphere. A refrigerant recovery & recycling unit must be used
whenever discharging the refrigerant system.
Operation of the recovery/recycling unit must be by AUTHORIZED PERSONNEL
Connect and operate a recovery/recycling unit in accordance with the manufacturers instructions.
f. Connect a cylinder of dry nitrogen (item 8, table D-1) to the gauge port of the discharge service valve.
Open the cylinder shutoff valve and the discharge service valve slightly and completely open the
suction service valve to purge the system of refrigerant gas. Use 1-2 cfm (0. 1.02 M 3/minute).
Dry nitrogen is always used to purge the refrigeration system during brazing or debrazing
of connections, to prevent internal oxidation scaling.