TM
9-4120-401-14
5 - 1 5 . FLUSHING THE REFRIGERANT SYSTEM. - continued
b. Purge.
Never pressurize refrigerant lines with oxygen. Mixing oxygen 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.
Purge the system with dry nitrogen regulated to approximately 30 psig (2.11 kg/cm2).
(a) Connect a line from the dry nitrogen cylinder regulator to POINT 5.
(b) Connect a line (without filter) from POINT 2 to the reservoir.
(c) Apply 28 volts do to solenoid valve wire leads to energize valve.
(d) Blow nitrogen through system for at least 30 seconds after moisture stops being discharged.
(e) Reverse the line at POINTS 2 and 5.
(f) Blow nitrogen through system for at least 30 seconds after moisture stops being discharged.
(g) Disconnect power from solenoid valve wire leads and remove power supply. Connect solenoid valve
wire leads using tags and wiring diagram (figure 4-6). Remove tags. (See paragraph 4-48.)
(h) Remove line from POINT 5 and cap POINT 5.
(i) Connect line from reservoir to POINT 3 and open suction line service valve.
(j) Blow nitrogen through system for at least 30 seconds after moisture stops being discharged.
(k) Remove line from POINT 3 and connect to POINT 6. Close suction line service valve and open
discharge line service valve.
Blow nitrogen through system for at least 30 seconds after moisture stops being discharged.
(l)
(m)
Close discharge line service valve. Remove lines from POINTS 2 and 6 and cap from POINT 5. Cap or
plug open connections if compressor and refrigerant desiccant dehydrator are not to be installed
immediately.
NOTE
FOLLOW-ON MAINTENANCE:
Install compressor (para 5-33).
Replace refrigerant desiccant dehydrator (para 5-22).
5-40
