TIF 25176B Refrigerant Recovery Machines 220V-240V 50_60 Hz, metric gauges - Manual (Page 8)

HELPFUL HINTS FOR
REFRIGERANT RECOVERY
PLANNING AHEAD
Knowing the quantity of refrigerant is important for plan-
ning storage requirements, as well as planning for the
actual recovery. For instance, any system with more than
5lbs. of refrigerant is likely to have areas where the liquid
can get trapped.
The key to a quick recovery procedure is to get the liquid
out first, and then get the remaining vapor out. However
most systems are not " recovery friendly." That is they
don't have access ports at their lowest points. If some
units you're servicing are on maintenance contracts, you
would save significant time by installing access ports at all
of the lowest points in the system, where liquid is likely to
accumulate.
Since most systems don't have these ports you need to be
prepared to boil off the trapped liquid with a heat gun,
when ever it's found. An indicator of trapped liquid in a
system is frost or condensation forming on the plumbing
or components where the liquid is trapped. The trapped
liquid may be in an area that is not visible. In all cases
trapped liquid in a system during recovery causes the
recovery process to slow down, regardless of the size or
type of machine ( see diagram).
If you are unable to locate the trapped liquid, but you
know it's there, because the recovery job is taking " forever".
Turn on the system compressor (if it's operable) for a few
seconds, this will get the refrigerant moving to another
part of the system and in the process pick up enough heat
to boil off.
HOSES AND VALVES
Hoses and Schrader valves have a large impact on recov-
ery speed. In general, the larger the hose, the less friction
on the flow of refrigerant, the quicker the recovery time.
Many contractors are now using 3/8' lines for the input to
the recovery machine, even those lines originating out of
1/4" fittings.
Schraeder valves must be removed from the connection
prior to an expedient recovery. Most wholesalers sell a tool
for removing these cores, while keeping the connection
sealed. The core depressor, in the end of the hose, should
also be removed. These two items can turn a 20 minute
job into one that goes on for hours. So, be sure to remove
the Schraeder valves and core depressors before every
recovery job.
Another hose consideration is the little rubber grommet at
the end of the hose that makes a seal with the flare fitting.
We've seen these seals so worn and deformed that when
the hose is connected to the flare fitting the grommet vir-
tually seals off the connection.
Refrigerant recovery has come a long way in a few short years. On the surface it's simply the process of taking refriger-
ant out of a system and putting it into a tank. However, this simple process can quickly become problematic if a few
items are overlooked. The following are some tips and pointers we've accumulated over the last few years that can save
you time and make the process go smoother.
First you need to identify the refrigerant type and quantity in the system you are servicing. If you determine it"s a
burnout, you need a special tank (a tank that's identified as containing burnout or other unidentified gases), and you
need to use extra filtration prior to recovery. (See item #2 on page 6)
If, on the other hand, you know the gas in the system is relatively clean or new, then a new tank should be used. If
you're planning on putting the refrigerant back into the same system after you have finished the service or if the refrig-
erant is going to be reclaimed, then use a tank that has the same refrigerant in it. A word of caution about the
Environmental Protection Agency (EPA): If you use a variety of refrigerant gasses in your service work - as evidenced by
your refrigerant purchases - and you only own one tank, you are asking for trouble. You would be well advised to own at
least one tank for every refrigerant type serviced, plus an extra for burnouts and other unknowns.
Results of Liquid Refrigerant
Trapped in a System
Tstart Time Tfinish
Forever
Pstart
Pe
0
10” Hg
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