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AIR CONDITIONING
24-39
present.
Do not breathe the fumes that are pro-
duced by the burning of refrigerant gas. Large con-
centrations of refrigerant in the presence of a live
flame become dangerously toxic. Observe the flame
through the window of the burner shield, not
through the top of the shield.
(1)
Open the torch valve until you hear a faint hiss
of escaping gas. Light the test torch and adjust the
valve until the flame is very small. A small flame will
detect large as well as small leaks, whereas, a large
flame will detect only large leaks. As soon as the re-
action plate seen through the window in the burner
shield becomes red hot, the tester is ready for use.
(2)
Examine all the tube connectors and other pos-
sible leak points by moving the end of the sampling
hose from point to point. Since refrigerant 12 is heav-
ier than air, it is good practice to place the open end
of the sampling hose directly below the point being
tested. Be careful not to pinch the sampling tube
since this will shut off the air supply to the flame
and cause a color change.
(3) Watch for a change in the color of the flame.
Small leaks will produce a green color and large leaks
a bright blue color. If leaks are observed at the tube
fittings, tighten the connection, using the proper flare
wrenches, and retest.
If the flame remains bright yellow when the tester
is removed from a possible leak point, insufficient air
is being drawn in through the sampling tube, or the
reaction plate is dirty.
REMOVE SWEEP-TEST CHARGE
If the system is free of leaks, or after correcting a
leak,
if
no air-conditioning components have been
removed, add the necessary refrigerant as described
under "Correcting the
Low
Refrigerant Level." If any
parts of the refrigerant system were disconnected re-
move the sweep-test charge. Close the refrigerant
manifold valve so that any refrigerant remaining in
the container is sealed. Remove the long
test
hose
OPERATE VACUUM PUMP A
NY
1
002A
Fig. 53-Evacuating
the System
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