5
PUSH-PULL LIQUID RECOVERY
The Push-Pull Liquid Recovery mode is
used for transferring large volumes of liquid
refrigerant. The R100 “Pulls” vapor from the
recovery cylinder and produces high
pressure discharge gas that “Pushes” liquid
out of a HVAC system into a recovery
cylinder. ( see figure 1)
Some systems may not allow push-pull
liquid recovery.
If any of the following
conditions apply to your recovery job,
proceed directly to Vapor Recovery.
Equipment contains less than 8
pounds of refrigerant.
Equipment is a heat pump or other unit
with a reversing valve.
Equipment has an accumulator
between the service ports used in
liquid recovery.
Liquid refrigerant has migrated and the
location of the refrigerant is not known.
The refrigerant system does not allow
for a solid column of liquid refrigerant
to be formed.
When using push-pull recovery, the
R100 will not recover to the required
vacuum level in the recovered system
.
Use a sight glass to determine when the
liquid is being “pushed” into the recover
tank. When liquid refrigerant is no longer
visible, switch to Vapor Recovery (see
figure 2).
The hose connections for liquid “push”
recovery are shown in the figure 1. Perform
the following steps for push-pull recovery:
1. Ensure the recovery unit
System Switch
is “OFF” and the power to the system to
be serviced is also turned off.
System On
SUCTION PRESSURE
TO POWER
SUPPLY
DISCHARGE PORT
SUCTION PORT
LIQUID
VAPOR
PURGE
RE COVER
D ISCHARGE P RESSURE
SWITCH
SUCTION PRE SSURE
O
CIRCUIT
BREAKER
O
High Pressure
Tank Full
SYSTEM
DISCHARGE PRESSURE
Charging
Scale
sight glass
liquid(open)
vapor(open)
recovery
tank
vapor service port
hvac unit
or appliance
liquid service port
Figure 1
