TM 9-4120-399-14
(h) Connect a nitrogen regulator and cylinder of dry nitrogen to the
center hose connection.
(i) Open the charging manifold valves and the nitrogen cylinder
and regulator valve. Allow system pressure to build up until
gages read 350 psig (24.7 kg./cm2).
(j) Perform leak tests, then discharge and purge the system, in
accordance with paragraphs 5-7 and 5-8 before performing
maintenance, or before evacuating and charging the system, as
appropriate.
(3) Final Leak Testing. Always perform a final leak test after performing any repair
or replacement of components before the air conditioner is reassembled and the
refrigeration system is evacuated and charged.
5-11. EVACUATING THE REFRIGERANT SYSTEM.
The refrigeration system must be
evacuated to remove all moisture before it is charged with refrigerant 22. To evacuate the
refrigeration system, perform the following procedures.
WARNING
DANGEROUS CHEMICAL
(R22)
is used in this equipment.
DEATH
or severe injury may result if personnel fail to observe safety precautions.
Use great care to avoid contact with liquid refrigerant gas being discharged
under pressure. Sudden and irreversible tissue damage can result from
freezing. Wear thermal protective gloves and a face protector or goggles
in any situation where skin-eye-contact is possible. Prevent contact of
refrigerant gas with flame or hot surfaces. Heat causes refrigerant to
break down and form carbonyl chloride (phosgene), a highly poisonous
and corrosive gas.
WARNING
REFRIGERANT UNDER PRESSURE
is used in the operation of this equipment.
DEATH
or severe injury may result if you fail to observe safety precautions.
Never use a heating torch on any part that contains refrigerant 22. Do
not let liquid refrigerant touch you, and do not inhale refrigerant gas.
CAUTION
Don't evacuate a leaking system. The vacuum created can cause air,
moisture, and dirt to enter system.
