Recovery
In the US we are required by the EPA under the Clean Air Act to Recover and Recycle refrigerant. This means that all CFC'S, HCFC's and HFC's must be recovered. If you yuse a hydrocarbon refrigerant there are currently no rules under the clean air act pertaining to this.
When working with refrigerants you need to use your head, refrigerants can cause suffocation in an enclosed space, so always use adequate ventillation. Refrigerants can cause frostbyte and can damage soft tissue. Concentrating and Inhalation of Refrigerants can cause cardiac sensitation and sudden death. Basically avoid working in enclosed spaces do not purposfully inhale refrigerants, use goggles and face shield and non permaible gloves work smart work safe.
Recovery is a simple process where the refrigerant in your system is pumped with the use of a compressor into a storage tank.
There are commercially available recovery systems,they cost from 350 to 800 for portable systems. Recovery tanks have a relief valve and a top vale and a bottom valve.
To recover gas on a sealed system such as the prometeia we must first install a tap that will not release the refrigerant to the atmosphere. These are available in both a tool type and a tap-a-line one time use valve. Once the piercing valve is installed we connect our recovery machine suction port to the prometeia, and the recovery machines discharge port to the tank's top valve ( gas port). Open the valves. We then turn the recovery machine on and run until the level of gas pressure in the prometeia is less than 10 inchs of mecury. We then close all valves and remove the recovery machine and hoses.
Preparing the tank for recovery if you have previosly recovered refrigernant in a tank you can check for the presesnce of air by measuring the pressure in the tank and checking the temperature. Check the pressure temperature chart for the temperature you found at the tank and if the pressure is higher then you have air in with the refrigerant (See Boyle's law of partial pressures) To remedy this under the clean air act you can purge the recovered gas by as much as 10% of the weight in the tank. Unless you are going to reuse the refrigerant this should not be nessassary. After purging a little let the tak retunr to ambient and recheck purge onlt in little spurts at a time.
Recovered gas cannot change ownership unless it is first brought to ARI 700 standards of purity.
When recovering gas never fill the recovery tank more than 80% full per unit volume, If in doubt check the water capacity and use that for a referance using the specific gravity of the refrigerant you will be using.
Tanks that are full and need to be disposed of can be taken to a local recycler or to a refrigerant supplier most have a swap out program for cylinders and charge 15 to 20 per swap... If the refrigerant is contaminated you will have to pay a disposal fee that can be as high as 1.20 per pound.
The fine for venting refrigerant into the atmosphere is 10,000 per incident.
Where do I find a recovery unit, supply house and on some of the online stores and auctions. The same goes for recovery tanks.
You will also need scales to tell how full the recovery tank is..
Vacuming
Triple evacuate your system this is when you use a gas to "sweep" the system clean between evacuations. Pull down times can be quite long if there is moisture in the system, Pull down to 500 microns using a standard vacume guage. Deeper is better on final evacuation go to 250 microns.
Charging systems
You will need to look at the type of system and refrigerant you will be using. R404 liquid charge only R507, R290, R134A all can be gas charged. A TXV system Liquid charge after pulling a vacume, charge into the liquid line or reciever flashing a little at a time until the suction pressure rises to 20 or 30 psi.. Fire system up then while under load top charge off to a full sight glass or subcooling. A capillary tube system will usually require less refrigerant, If charging with R404 or another non azoetrope charge with the tank bottom up and flash the liquid off in the guages otherwise charge with a gas only.
Each system has pecularities which make he system charge unique. When a Manafacturer mass produces the charge is calculated to be a very near fit so that the production of these machines can be done with ease. This is why we do not post any amounts of charge required for these systems.
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Originally Posted by Thrilla
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