TM 9-4120-388-14
5-8. PURGING THE
REFRIGERANT SYSTEM.
INITIAL SETUP:
Equipmemt Condition
Refrigerant system discharged (5-7).
MATERIALS/PARTS
The refrigeration system must be purged with dry nitrogen (item 9, Appendix E) before any brazing performed on any
component. A flow of dry nitrogen at the rate of less than 1-2 cfm (0.028-0.057 m3/minute) should be continued during
all brazing operations to minimize internal oxidation and scaling.
Nitrogen cylinders are pressurized containers The pressure in the cylinder can
exceed 2000 psi. A nitrogen pressure regulator should be used at all times when
nitrogen is used for leak check or purge operations.
Nitrogen is an inert gas. However, it also presents danger as a suffocant and,
therefore, must also be discharged in a ventilated location.
Assuming that the system has been discharged using a manifold as described in paragraph 5-7, proceed as follows:
a. See specific component removal/repair instructions.
c. Connect the center hose from the changing manifold to a nitrogen regulator and dry nitrogen tank.