LEAK TESTING - TM-9-4120-428-140225

TM 9-4120-428-14

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DIRECT SUPPORT MAINTENANCE

AIR CONDITIONER, HORIZONTAL, COMPACT

(NSN 4120-01-502-1319)

LEAK TESTING

INITIAL SETUP:

Materials/Parts

Tools

Nitrogen, WP 0000 00, Item 8

Refrigeration Unit Service Tool Kit, WP 0000 00, Item

Refrigerant R-22, WP 0000 00, Item 4

Goggles, WP 0000 00, Item 2

Equipment Condition

Gloves, WP 0000 00, Item 2

Nitrogen Regulator, WP 0000 00, Item 7

Remove Top Panels (WP 0061 00)

Install service manifold (WP 0064 00)

WARNING

Never pressurizes lines with oxygen, mixture with oil will cause an explosion.

The pressure in a nitrogen cylinder can exceed 2000 psi. A nitrogen pressure regulator

should be used at all times to avoid personal injury.

Nitrogen is an inert gas that can cause suffocation and must be discharged in a well-

ventilated area.

NOTE

Test for leaks with either a refrigerant gas leak detector or a strong solution of liquid

detergent in water.

If an electronic refrigerant gas leak detector is available, it should be used in accordance

with the procedures contained in TM 9-4940-435-14, Leak Detector, Refrigerant Gas.

Unit contains R-22, a chemical substance that harms public health and the environment

by destroying ozone in the upper atmosphere. Qualified personnel must service

equipment only.

To perform leak testing by use of the electronic detector, it is necessary that the system

be pressurized with a proportion of refrigerant gas. To perform leak testing by use of the

soap solution method, the system may be pressurized with dry nitrogen alone.

A. To pressurize a system that has some refrigerant charge:

1) Connect the 1/4 inch yellow hose (charge) to a Refrigerant-22 (R-22) cylinder.

2) Open the service manifold compound gauge, pressure gauge, and the charge valves.

3) Check that the service manifold vacuum valve is closed.

4) Open the refrigerant cylinder valve and pressurize the system to 100 psi (7.1 kg/cm2).

5) Test for leaks at all points of possible leaks by using an electronic refrigerant gas leak detector or by

brushing on a soap solution while closely observing for bubbles to form.

6) If a leak is detected, discharge and purge the system and repair the leak. Retest for leaks.

7) If a soap solution was used to test for leaks, thoroughly rinse test areas with fresh water.

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