TB 9-2320-360-13&P-1
A/C SYSTEM REFRIGERANT (R-134A) MAINTENANCE - CONTINUED
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PURGING
WAR N I N G
Wear protective goggles and nonleather gloves when purging or injury may result.
CAU T I ON
Dry nitrogen gas is recommended for purging. A pressure regulator is required to regulate gas pressure
between 0 and 200 psi (0-1379 kPa). Commercial cylinders of nitrogen contain pressures in excess of 2000
psi (13,790 kPa). This pressure must be reduced to 200 psi (1379 kPa) for purging or damage to equipment
may result.
1.
Recover system refrigerant.
2.
Disconnect both ends of line or component to be purged.
3.
Install caps or plugs tightly on system lines or components at disconnect points.
4.
Ensure valves (1, 2, and 3) are closed.
5.
Connect supply line valve (3) to outlet end of component or line.
6.
Connect drain line (4) to inlet end of component or line.
7.
Connect outlet end of drain line (4) to recycling system container (5) or to waste container (6).
8.
Adjust nitrogen bottle regulator/gage (7) to 200 psi (1379 kPa).
9.
Open nitrogen bottle control valve (1) and purging control valve (2), then slowly open supply line valve (3). Check drain
line (4) for gas flow.
10.
Let nitrogen flow at 200 psi (1379 kPa) for 1 to 2 minutes. If component or line was very wet, let nitrogen flow until
there is no trace of refrigerant oil or solid bits of dirt or grit flowing from drain line (4).
11.
Close nitrogen bottle control valve (1) and purging control valve (2) first, then close supply line valve (3).
12.
Disconnect supply line valve (3) and drain line (4). Tightly cap both ends of component or line.
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