TM 9-4110-254-14
5-10. LEAK TESTING THE REFRIGERANT SYSTEM.
This task covers.
Testing
INITIAL SETUP
Tools:
General Safety Instructions:
Refrigeration Unit Service Tool Kit
WARNING
4, Section III, Appendix B
Nitrogen Regulator
Never
pressurize refrigerant lines with
6, Section III, Appendix B
oxygen, mixture with oil could cause an
Equipment Conditions:
explosion.
Service manifold installed para 5-6).
The pressure m a nitrogen cylinder can
exceed 2000 psi. A nitrogen pressure
Materials/Parts-
regulator should be used at all tines to
Refrigerant R-134a
avoid personal injury.
12, Appendix E
Nitrogen is an inert gas that can cause
Nitrogen
suffocation and must be discharged m a
11, Appendix E
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.
(d) Open refrigerant cylinder valve and pressurize system to 100 psi (7.1 kg/cm2).
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