5-8. LEAK TESTING THE REFRIGERANT SYSTEM (cont)
Connect the refrigerant-22 drum so that only gas will be used for pressurization.
(c) Connect a drum of refrigerant -22 to the center hose connection of the charging manifold
(d) Open the charging manifold valves.
(e) Open the refrigerant drum valve slightly and adjust as necessary to prevent formation of frost and
allow system pressure to buildup until the gages read 40-50 psi (2.8-3.5 kg/cm2).
(f) Close the charging manifold valves and the refrigerant drum valve.
(g) Remove the refrigerant -22 drum from the center hose connection.
(h) Connect a nitrogen regulator and cylinder and cylinder of dry nitrogen to the center hose
(i) Open the charging manifold valves and the nitrogen cylinder and regulator valve. Allow system
pressure to buildup until gages read 350 psi (24.7 kg/cm 2).
(j) Perform leak tests, then discharge and purge the system, in accordance with paragraphs 5-5 and 5-6
before performing maintenance, or before evacuating and charging the system, as appropriate.
(3) Final Leak Testing. Always perform a final Ieak test after performing any repair or replacement of components
before the air conditioner is reassembled and the refrigeration system is evacuated and charged.