Purging Refrigerant System

TM 5-4120-393-14

5-10. Purging Refrigerant System

This task covers:

a. Service

Initial setup.

Tools:

Tool kit, service, refrigeration unit NSN 5180-00-596-1474

Safety goggles NSN 4240-00-052-3776

Personnel: 1

Materials:

Nitrogen (Appendix E, item 4)

Equipment condition:

1. Turn unit power off at power source. If there is a chance that it will be turned on, also disconnect power cable

to air conditioner.

2. Discharge the refrigerant system. See para 5-9.

General Safety Instructions:

WARNING

Death or serious injury may result if personnel fail to observe safety precautions.

Use great care to avoid contact with liquid refrigerant or refrigerant gas being

discharged under pressure. Sudden and irreversible tissue damage can result

from freezing. Wear thermal protective gloves and a face protector or goggles in

any situation where skin-eye-contact is possible.

Prevent contact of refrigerant gas with flame or hot surfaces. Heat causes the

refrigerant to break down and form carbonyl chloride (phosgene), a highly

poisonous and corrosive gas.

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. Do not allow nitrogen

pressure regulator setting to exceed 200 psig during purging.

Nitrogen is an inert gas. However, it also presents danger as a suffocant and,

therefore, must also be discharged in a ventilated location.

NOTE

The refrigeration system must be purged with dry nitrogen, item 4, Appendix E,

before any brazing or debrazing is performed on any component. A flow of dry

nitrogen at the rate of less than 1-2 cfm (0.028-0.057 m /minute) should be

continued during all brazing or debrazing operations to minimize internal oxidation

and scaling.

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