15
G5TWIN OPERATION MANUAL
© 2016 APPION INC. - ALL RIGHTS RESERVED
Helpful Hints
(continued)
For the fastest recovery speeds, it is necessary to pump out the liquid first. Using the Direct Connection
procedures in this manual, on a typical system, you
should
expect the “liquid recovery” stage to move
the bulk
of the entire system charge as liquid
- this means it
should go very quickly
for most of the recovery process
(in
most larger systems, this could be over 90% of the refrigerant charge)
.
However, if you observe
hot recovery cylinders, or very slow recovery after only moving a few pounds of
refrigerant, then you
likely have input restrictions
. You may further confirm input restrictions by checking for
frost or condensation at each hose/port connection between the AC/R System and the recovery machine
(e.g., the system access port, or the inlet fitting to the recovery machine). Input restrictions can cause liquid
refrigerant to get trapped behind the restriction, causing recovery to be slower than the expected vapor rate
(see Diagram 8)
, and unexpectedly adding heat
to the recovery cylinder.
What Happens With Input Restrictions:
Input restrictions will greatly slow down
refrigerant recovery by preventing the full “liquid
flow” from reaching the recovery machine. The
pressure drop caused by the recovery machine
triggers a liquid-to-vapor expansion at the point
of restriction, which drops the temperature of
the liquid refrigerant at the restriction. As the
point of restriction continues to get colder, the
vapor pressure drops, slowing the vapor flow.
Pretty soon, the recovery machine is only receiving a reduced flow of vapor that is now picking up ambient
heat and adding it to the heat of compression. All of this heat is sent along to the recovery cylinder, quickly
raising the recovery cylinder temperature.
Efforts to cool a cylinder are more effective when there is liquid refrigerant, as the liquid aids in transferring
heat through the cylinder walls to the “bucket of ice” or cooled airflow. However, if contents of the tank are
mostly vapor, efforts to cool the tank (e.g., airflow, ice) could be less effective than expected.
Remove Input Restrictions to Maximize Recovery Performance:
For the fastest recovery times, take the time to address these typical input restrictions before you start:
•
Remove core depressors from all of the hose fittings (they block up to 50% of the flow) -
See Tip #4
•
DO NOT USE refrigerant charging hoses with “quick disconnect” or “auto-shutoff” fittings
•
Remove “Schrader”-type access valves using a Valve Core Removal Tool -
See Tip #4
•
Discard of used/worn hoses with deteriorating inner linings
With a full flow of liquid refrigerant, the G5Twin will quickly fill the recovery cylinder with cool liquid. Once the
liquid recovery is complete, the remaining vapor will be pumped into a cooler tank, resulting in lower final
temperatures and faster overall recovery speeds.
Input Restrictions: Slow Recovery & Hot Recovery Cylinders
TIP #2
Diagram 8
