TM 9-4120-378-14
5.7 REFRIGERATION SYSTEM SERVICING - (LEAK TEST). - Continued
Action
Remarks
Location/Item
If the soap solution testing method is
used, thoroughly rinse with fresh water
after testing is completed. A residual
soap film will attract and accumulate an
excessive amount of dust and dirt dur-
ing operation.
c . Testing Procedures. To perform leak testinG by use
of the eIectronic detector, it is necessary that the sys-
tem be pressurized with a proportion of refrigerant
gas. To perform leak testing by use of the soap solu-
tion method, the system may be pressurized with dry
nitrogen alone.
(1) To pressurize a system that has some refriger-
ant charge, for either leak testing method:
(a) Remove the hose connection protective
caps from the high and low pressure ser-
vice valves.
(b) Connect the hoses from a charging man-
ifold to the service valves.
NOTE
If it is possible that the problem may not
be a leak and that you may not have to
replace a refrigeration system compo-
nent, refrigerant-22 may be substituted
for the nitrogen in the following test. If ni-
trogen is used, you will have to dis-
charge, evacuate, and recharge the
system after this test is completed.
(c)
Connect a nitrogen pressure regulator and
nitrogen bottle to the center hose connec-
tion of the charging manifold.
Open the unit service valves and the
(d)
charging manifold valves.
Open the nitrogen tank valve and pressur-
(e)
ize the system to 300 psig (21.2 kg/cm2).
Perform leak tests.
(f)
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