# Recovering refrigerant back into disposable cylinder



## bfletcher7 (Jan 16, 2016)

It is a question worthy of an answer from the pros but I would be way too chicken to attempt it, lol. I see your logic but the refrigeration manual warns several times against doing that. Elsewhere in that manual it reads "Most new virgin and disposable refrigerant cylinders have check valves that allow the refrigerant to leave the cylinder—but nothing can enter it."


----------



## BayouRunner (Feb 5, 2016)

bfletcher7 said:


> It is a question worthy of an answer from the pros but I would be way too chicken to attempt it, lol. I see your logic but the refrigeration manual warns several times against doing that. Elsewhere in that manual it reads "Most new virgin and disposable refrigerant cylinders have check valves that allow the refrigerant to leave the cylinder—but nothing can enter it."


You nailed it


----------



## sidejobjoe (May 30, 2014)

Yep, guess the check valve nixes that idea


----------



## roughneck (Nov 28, 2014)

The check valve built into refrigerant cylinders would prevent this.


----------



## beenthere (Oct 11, 2008)

And if they didn't. The relief valve of that virgin R22 refrigerant cylinder could blow out, losing you all of the expensive R22.


----------



## Bob Sanders (Nov 10, 2013)

The old r12/r22 tanks did not have a check valve and I have used them before for recovery.


----------



## beenthere (Oct 11, 2008)

Bob Sanders said:


> The old r12/r22 tanks did not have a check valve and I have used them before for recovery.


How full were they with virgin refrigerant when you put hot refrigerant in them.


----------



## Bob Sanders (Nov 10, 2013)

beenthere said:


> How full were they with virgin refrigerant when you put hot refrigerant in them.


Maybe about 1/3 to 1/2 way. Never more than that.


----------



## bfletcher7 (Jan 16, 2016)

Probably because I'm inexperienced and don't know what risks can be taken I would never attempt this. To me, the convenience is being able to connect an approved storage cylinder and remove several ounces without dragging-out the recovery machine. I would be ensured of a safe procedure with just a couple extra minutes.


----------



## Bob Sanders (Nov 10, 2013)

bfletcher7 said:


> Probably because I'm inexperienced and don't know what risks can be taken I would never attempt this. To me, the convenience is being able to connect an approved storage cylinder and remove several ounces without dragging-out the recovery machine. I would be ensured of a safe procedure with just a couple extra minutes.


Well, it's not exactly legal and I wouldn't suggest anyone do it. The last time I did it was when r12 was on its way out and the tanks still didn't have check valves. Since then however I have grown up a little, but this is primarily the reason why they started sticking check valves in.... to prevent back yard guys like me from hurting myself or some one else.


----------



## beenthere (Oct 11, 2008)

Plus, not worth risking the loss of a lot of refrigerant to save a few ounces.


----------



## supers05 (May 23, 2015)

Most of those check valves are removable for the so inclined.... 

If it's just a few ounces, you really have nothing to worry about, other then contamination if it's a previous burnout. With that said, I would never fill any container, regardless of type without a scale though, and monitoring it's temperature. 

The ultimate risk is that the tank could rupture. All it takes is a faulty relief and/or hydrostatic expansion. (very large increases of pressure with small increases of temperature, when the container is completely full of liquid) There have been cases where someone thought it was a good idea to hook up a tank as a receiver while leaving it in the sun. It lasted just long enough for the offending person to lose their legs. (parts of the equipment blocked some of the shrapnel) 

This is also a concern with leaving compressed containers in saturation, in hot locations. (Direct sunlight, car trunks, back of vans, etc.) If the relief valve isn't in contact with only vapor, the valve will no longer be sufficient in preventing over-pressurisation. 

Cheers!


----------

