Komatsu 830E Shop Manual page 571

Purging Air From Service Hoses
The purpose of this procedure is to remove all the
air trapped in the hoses prior to actual system test-
ing. Environmental regulations require that all ser-
vice hoses have a shutoff valve within 12 inches of
the service end. These valves are required to
ensure only a minimal amount of refrigerant is lost
to the atmosphere. R-134a gauge sets have a com-
bination quick disconnect and shutoff valve on the
high and low sides. The center hose also requires a
valve.
M09010 05/02
The initial purging is best accomplished when con-
nected to recovery or recycle equipment. With the
center hose connected to the recovery station, ser-
vice hoses connected to the high and low sides of
the system, we can begin the purging. The manifold
valves and service valves should be closed. Activat-
ing the vacuum pump will now pull any air or mois-
ture out of the center hose. This will require only a
few minutes of time. The hose is the only area that
is being placed in a vacuum and this will not require
a lengthy process. Closing the valve will then insure
the hose is purged. It is now safe to open the other
manifold valves.
FIGURE 9-9. PURGING SYSTEM
Air Conditioning System
for HFC 134a Refrigerant
M9-15