TM 9-4120-407-14
(f) If a leak is found, discharge and purge system, and repair leak. Retest for leaks. See
(2) To pressurize a system that has been dischawed and purged:
(a) Connect the charge hose to a cylinder of Refrigerant R-22 set to deliver gas only.
(b) Open the service manifold compound gauge, pressure gauge, and charge valves.
(c) Check that service manifold vacuum valve is closed.
2
(d) Open refrigerant cylinder valve and pressurize system to 40-50 psi (2.8-3.5 kg/cm ).
(e) Close service manifold valves and refrigerant cylinder valve.
(f) Disconnect charge hose from the refrigerant cylinder.
(g) Connect the charge hose to a nitrogen regulator and dry nitrogen cylinder.
( h ) Open the service manifold compound gauge, pressure gauge, and charge valves.
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(i) Open nitrogen cylinder valve and pressurize system to 350 psi (24.7 kg/cm ).
(j) Close service manifold valves and nitrogen cylinder valve.
(k) Test for leaks at all points of possible leakage using an electronic refrigerant gas leak detector.
(l) If a leak is found, discharge and purge system, and repair leak. See paragraphs 4-12
thru 4-14.
(m) After performing leak test, discharge and purge system before performing maintenance, or
evacuating and charging system, as appropriate. See paragraphs 4-12 and 4-13.
NOTE
FOLLOW-ON MAINTENANCE:
4-39