HOSES AND VALVES
Hoses and Schrader valves have a large impact on recovery speed. In general, the
larger the hose, the less friction on the flow of refrigerant and the quicker the recovery
time. Many contractors are now using 3/8” lines for the input to the recovery machine,
even if those lines originate out of 1/4” fittings.
Schrader 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 Schrader 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 worm and deformed that
when the hose is connected to the flare fitting the grommet virtually seals off the the
connection. 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 economically justified in most cases. It’s still a great idea to
do as much cleaning of refrigerant going back into the same system (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 separate the refrigerant from the oil in order to
measure the oil (to know how much oil to charge back into the system). However
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 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
expressing 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.