TM 9-4110-256-14
5-11.
LEAK TESTING THE REFRIGERANT SYSTEM.
This task covers:
Testing
INITIAL SETUP
Tools:
General Safety Instructions:
Nitrogen Regulator
WARNING
5, Section III, Appendix B
Never pressurize refrigerant lines with
Equipment Conditions:
oxygen, mixture with oil could cause an
Service manifold installed (para 5-7).
explosion.
Materials/Parts:
The pressure in a nitrogen cylinder can
exceed 2000 psi. A nitrogen pressure
Refrigerant R-134a
regulator should be used at all times to
12, Appendix E
avoid personal injury.
Nitrogen
11, Appendix E
Nitrogen is an inert gas that can cause
suffocation and must be discharged in a well
ventilated area.
Testing.
NOTE
To perform leak test, it is necessary that the system be pressurized with a
proportion of refrigerant gas.
The electronic gas tester is highly sensitive to the presence of a minute
quantity of gas in the air, and is quite effective in the detection of small leaks.
However, due to rapid dispersion of refrigerant gas into surrounding air,
difficulty may be encountered in pinpointing large leaks. The detector must
be used in a well ventilated area but draft free area. Use procedures contained
in TM 9-4940-435-14, "Leak Detector, Refrigerant Gas".
(1)
To pressurize a system that has some refrigerant charge.
(a)
Connect the charge hose to a refrigerant cylinder containing refrigerant R-134a set to deliver gas
only.
(b)
Check that service manifold vacuum valve is closed.
(c)
Open the service manifold compound gage, pressure gage, and charge valves.
Open refrigerant cylinder valve and pressurize system to 100 psi (7.1 kg/cm2).
(d)
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