SERVICING REFRIGERANT SYSTEM. (cont)

TM 5-4120-369-14

Refer to figure 6-1 and purge the refrigerant

(3) Purging the Refrigerant System.

system as follows:

Avoid bodily contact with liquid refrigerant and avoid inhaling

refrigerant gas. Be especially careful that refrigerant 22 does

not come in contact with eyes. In case of refrigerant leaks,

ventilate area immediately.

Step 1.

Remove high pressure charging valve cap.

Connect valve to a cylinder of dry nitrogen.

Step 2.

Attach a suitable discharge hose to low pressure charging valve.

Step 3.

Step 4.

Open Nitrogen valve and allow nitrogen to flow through system

until all moisture is forced out.

Close nitrogen cylinder valve.

Step 5.

Charge system.

Step 6.

(4) Evacuating the System. Refer to Figure 6-1 and evacuate the system as follows:

Connect a vacuum pump to high and low pressure charging valves.

Step 1.

Step 2.

Start vacuum pump and record time for maximum vacuum reading

on gage.

Step 3.

Continue evacuating for an equal period of time.

Stop pump and observe gage. If vacuum holds for a time equal

Step 4.

to pump down time, evacuation is satisfactory.

Charge refrigeration system.

Step 5.

Refer to Figure 6-1 and charge the system with

(5) Charging the System.

refrigerant as follows:

Avoid bodily contact with liquid refrigerant and avoid inhaling

refrigerant gas. Be especially careful that refrigerant 22 does

not come in contact with eyes. In case of refrigerant leaks,

ventilate area immediately.

NOTE

Steps 1, 2, 3 and 4 apply only to a completely evacuated

system. A fully charged system contains 5 .5 pounds

(1 .23 KG) of refrigerant 22. To add refrigerant to an

incompletely charged system, refer to STEP 5.

NOTE

Before proceeding with charging procedure all covers, panels

and grilles must be in place.

6-4