Specifications

This is probably never noticed in charging, because the
pressure opens the grommet, but during recovery (or with
suction) the deformed grommet severely restricts the flow
of refrigerant.
REFRIGERANT RECYCLING
Current regulations state that used refrigerant shall not be
sold, or used in a different owner's equipment, unless the
refrigerant has been laboratory analyzed and found to meet
the requirements of ARI 700 (latest edition). As a result,
recycling and verifying ARI 700 conformance isn't econom-
ically justified in most cases. It's still a great idea to do as
much cleaning of refrigerant going back into the same sys-
tem (or owners system) as possible. We recommend using
the largest, high-acid capacity filter, that are economically
feasible. Put these filters on the suction or inlet side of the
recovery unit. Change filters often.
The recovery of large amounts of liquid refrigerant can
sometimes carry with it large quantities of oil, if the system
being serviced doesn't have an adequate oil separator
installed. If this recovered refrigerant isn't going to be liquid
charged back into the same system, you might want to sep-
arate the refrigerant from the oil in order to measure the oil
(to know how much oil to charge back into the system).
Refrigerant sent back for reclaim does not need to have the
oil removed. One of the simplest and most cost effective
ways to achieve this is to use a 13.6kg or 22.7kg (30 or 50
lb.) tank in line with your recovery machine. Connect the
system to the liquid port of the tank, then from the vapor
port of the tank connect to the input of your recovery
machine. A second tank, for storing refrigerant, should then
be connected to the output of the recovery machine. If you
encounter large amounts of liquid you will need to put a
band heater around the first tank. When the recovery job is
complete the oil can be removed, from the first tank, by
applying a small amount of pressure, using nitrogen, to one
of the ports and extracting the oil from the other. If you are
going to remove the oil from the vapor port you will need to
turn the tank upside down. Always wear safety glasses
when performing this operation as the oil may be acidic and
could cause severe burning.
KEEPING THE DIRT OUT
During the recovery process your recovery machine can be
exposed to debris that can, potentially, damage it. This
includes brazing spatter and copper/ brass slithers. Further
contamination can be introduced from the refrigerant stor-
age tanks. To prolong the life of your recovery machine,
always use an inline filter at the inlet Port.
Whenever you are charging a system from a recovery cylin-
der it is a good idea to use an in-line filter to protect the sys-
tem from contamination. Again, change your in-line filters
often.
GETTING THE LIQUID OUT
See diagram on page 13 of this manual
Push/pull is a method of removing bulk liquid from a sys-
tem using the pressure differential created by the recovery
machine. Push-pull will generally not work on smaller sys-
tems because there is no bulk liquid reservoir to create a
siphon from.
Push-pull is mostly used on systems with a receiver tank or
those with greater than 9.1kg (20 lbs.) of refrigerant, or
when transferring from one tank to another. The rate of liq-
uid transfer is very much dependent on hose size, with larg-
er hoses providing much better throughput.
Another trick is to cool the tank, if it's partially filled, prior
to or during recovery. This operation will lower the pressure
in the storage tank and therefore speed up recovery. There
must be a minimum of 2.3kg (5 lbs) of liquid refrigerant in
the tank you wish to chill. This operation can be performed
prior to or during the recovery. See the two set updiagrams
and procedures on pages 13-14 of this manual.
There is nothing magic here, you are simply using your
recovery machine to make a refrigerator where the tank is
the evaporator. By throttling the output valve, you're effec-
tively creating a capillary tube or an expansion device, but
you need to adjust the back pressure to suit the conditions
and the refrigerant. Five to ten minutes of chilling can pro-
duce some very dramatic tank cooling, depending on the
conditions. If there are any non condensables in the tank
this process will not work. The greater the quantity of refrig-
erant in the tank the longer the process will take.
9
HELPFUL HINTS FOR
REFRIGERANT RECOVERY - cont.