TM 9-4120-403-14
5-8. PURGING THE REFRIGERANT SYSTEM
This task covers:
a. Service
INITIAL SETUP
Tools
General Safety Instructions
Tool Kit, Refrigeration
WARNING
Nitrogen Regulator
Nitrogen is an inert gas. However, it also presents
danger as a suffocant and, therefore, must also be
Materials/Parts
discharged in a ventilated location.
Nitrogen
Equipment Conditions:
The refrigeration system must be purged with dry nitrogen before any brazing is 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.
CAUTION
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.
a. See specific component removal/repair instructions.
c. Connect the center hose from the charging manifold to a nitrogen regulator and dry nitrogen tank.
d. The hose from the high pressure service valve to the charging manifold must be connected.
e. The hose from the low pressure service valve must be disconnected from the charging manifold.
f. Open both service valves on the unit.
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