TM9-4120-400-14
LEAK TESTING. - continued
5-14.
1. To pressurize a system that has some refrigerant charge:
a.
Connect the yellow 1/4 inch (charge) hose to a Refrigerant -22 cylinder.
b. Open the service manifold compound gauge, pressure gauge, and charge valves.
c.
Check that service manifold vacuum valve is closed.
Open refrigerant cylinder valve and pressurize system to 100 psi (7.1 kg/cm2).
d.
Test for leaks at all points of possible leakage using an electronic refrigerant gas leak detector or brushing
e.
on a soap solution while closely observing for bubbles to form.
f.
If a leak is found, discharge and purge system, and repair leak. Retest for leaks. (See para 5-12.)
If a soap solution was used to test for leaks, thoroughly rinse test areas with fresh water.
g.
h.
If a leak was not found, check unit charge. (See para 5-16.)
2. To pressurize a system that has been discharged and purged:
a.
Connect the yellow 1/4 inch (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.
Open refrigerant cylinder valve and pressurize system to 40-50 psi (2.8 -3.5 kg/cm2).
d.
e. Close service manifold valves and refrigerant cylinder valve.
f.
Disconnect the yellow 1/4 inch (charge) hose from the refrigerant cylinder.
Connect the yellow 1/4 inch (charge) hose to a nitrogen regulator and dry nitrogen cylinder.
g.
h.
Open the service manifold compound gauge, pressure gauge, and charge valves.
Open nitrogen cylinder valve and pressurize system to 350 psi (24.7 kg/cm2).
i.
Close service manifold valves and nitrogen cylinder valve.
j.
k.
Test for leaks at all points of possible leakage using an electronic refrigerant gas leak detector or brushing
on a soap solution while closely observing for bubbles to form.
l.
If a leak is found, discharge and purge system, and repair leak. Retest for leaks. (See para 5-12.)
m. If a soap solution was used to test for leaks, thoroughly rinse test areas with fresh water.
n
After performing leak tests, discharge and purge system before performing maintenance, or evacuating
and charging system, as appropriate. (See para 5-10 and 5-11.)
NOTE
FOLLOW-ON MAINTENANCE:
Install top panels(para 4-11).
5-38