WD Catalog 2018

9-5

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Recovering and Recycling the Refrigerant

Purging Non-Condensable Gases (Air)

During purging and refrigerant recovery air can be entrapped in the

refrigerant container. Air must not be put into an AC system. The result is

higher operating pressures and possible system damage.

A simple check can be performed as follows:

Store the recovered refrigerant at constant temperatures

above 65

F (18.7

C). The container should include a pressure

gauge reading to 1 psi increments. The container should not

be in direct sunlight or near a heat source.

Use a calibrated thermometer to establish temperature

within 4 inches of the container.

Compare the pressures for like temperatures in Figure 9-2.

Note the separate charts for R-12 and R-134a. If the container

pressure is equal to or less than the pressure shown in the

table, excess air is not present.

If container pressure is greater than shown in the table,

connect the container to recovery or recycle equipment with

the pressure gauge in place.

Bleed a small amount of vapor from the container until the

pressure is below that shown on the table, then close the

valve.

Tank temperature may change during the bleed off process.

Mild shaking will assist in temperature stabilizing, but it is a

good idea to let it set for several hours before again checking

pressure against the table.

If the pressure remains above that shown on the table, excess

air or another contaminant (i.e., another refrigerant) is still

present. This material must be recycled or reclaimed.

If the pressure is equal or below that shown on the table

identify the cylinder as “recycled.”