Wear protective goggles and nonleather gloves when servicing air conditioner or injury may result.
Dry nitrogen gas is recommended for purging. A pressure regulator is required to regulate gas pressure
between 0 and 200 psi (0-1,379 kPa). Commercial cylinders of nitrogen contain pressures in excess of
2,000 psi (13,790 kPa). This pressure must be reduced to 200 psi (1,379 kPa) for purging or damage to
equipment may result.
Recover system refrigerant (refer to b. Recovery).
Disconnect component to be purged from air conditioning system.
Install caps or plugs tightly on air conditioning system lines that were disconnected from component.
Close three valves (1, 2, and 3).
Connect supply line valve (3) to outlet end of component or line.
Connect drain line (4) to inlet end of component or line.
Connect outlet end of drain line (4) to recycling system container (5) or to waste container (6).
Adjust regulator/gage (7) on nitrogen bottle (8) to 200 psi (1,379 kPa).
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 200 psi (1,379 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.