Liquid Push-Pull Recovery Operations - Bacharach High Performance Oilless Commercial Refrigerant Recovery Unit User Manual

Liquid Push-Pull Recovery Operations

Attention: Before attempting liquid push-pull recovery operations,
please review this page.
A scale or liquid-sight glass can be used to determine when all the liquid is recovered. The
STINGER will not pull a vacuum using the liquid push-pull recovery operation. To finish the
recovery operation, you must perform vapor recovery operations as described on Page 9.
GUIDLINES:
If any of the following conditions are present in the system being evacuated, the liquid push-
pull operations may not be practical and vapor recovery operations should be performed.
The equipment contains less than 20 lbs of refrigerant.

The equipment is a heat pump or other system with refrigerant flow that would prevent

you from isolating the liquid.
Equipment has an accumulator between the service ports used in the liquid recovery

process.
Liquid refrigerant migration has occurred and the location of the liquid is unknown.

The refrigerant tubing design on the equipment does not allow for a solid column of

liquid refrigerant to be formed.
STEPS:
The liquid push-pull recovery method requires the use of a third hose. In addition, a sight-
glass is useful for determining when all of the liquid has been pushed out of the system. After
all the liquid has been pushed out, you will need to reconfigure the hoses for vapor recovery
since the liquid push-pull recovery method does not pull a vacuum on the system.
1. Remove power from the refrigerant device to be evacuated.
2. Make proper hose connections for liquid push-pull recovery as shown in the diagram
on Page 12.
CAUTION: If the 80% tank full shutoff cord is not used, then use a scale to monitor the
refrigerant level in the recovery cylinder in order to prevent overfilling.
CAUTION: When recovering R-410A, you must use a recovery cylinder approved for
use with R-410A. Standard recovery cylinders with 350 psi working pressures are not
approved for use with R-410A.
3. Turn the inlet and outlet valves to their "OPEN" position and the PURGE valve to its
"PURGE" position. Note: The "PURGE" position bypasses the condenser, optimizing
the push-pull flow rate.
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