[GMCnet] R12 vs R134 in a recovery tank

[Chris Tyler]

Is there a test strip or some way to tell if the contents of a recycling tank is R12 or R134?

Scored a Snap On refrigerant recovery system at a swap meet today for cheap. I will be happy if it simply functions as a vaccuum pump. However, the
fellow said he had used it int the junkyard to recover R12 from older cars and the tank has quite a bit in it.

My coach is R12 right now and funtioned when I got it a little over a year ago. It still has pressure but is low. I suspect a slow leak at the
compressor. I would like to keep it R12. If i have to convert it I will go with duracool.It would be nice if the R12in the tank is usable given the
cost. I know about the problems mixing the two [although several friends have done so with no problems for several years I dont want to risk that] so
wondering if there was a way to tell what it is with any degree of certainty
--
76 Glenbrook
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

[Jim Miller]

On Dec 7, 2014, at 6:29 PM, Chris Tyler wrote:

> Is there a test strip or some way to tell if the contents of a recycling tank is R12 or R134?

Why not attach a gauge to the tank and measure pressure vs. temperature at various temperatures? Then compare your measurements to the published P/T graphs for common refrigerants? Naturally you'll want to get as many data points as possible so I'd try taking measurements with the tank in several different locations - eg indoors, outdoors, in a deep freeze and perhaps submerged in hot bathwater.

There are also flame tests that will let you identify the presence of chlorine which, if present, would let you rule out the specimen being a modern non-chlorinated refrigerant like R-134A.

--Jim "saving the lives of Onans...one unit at a time" Miller
1977 Eleganza II
1977 Royale
Hamilton, OH

[Emery Stora]

You are correct that R134a doesn’t contain chlorine as it is 1,1,1,2-Tetrafluoroethane.

R12 does contain chlorine as it is Dichlorodifluoromethane

However note that they both contain fluorine.

Many tests would have a hard time checking for chlorine because of the fluorine
being present.

Emery Stora

[Espen Heitmann]

I would discharge it, it could be a good mixture of freeze 12, leak stop, R12 and R134a or whatever in it.
So get it drained and a small flush to be on the safe side :)
--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

[Jim Miller]

On Dec 7, 2014, at 11:51 PM, Emery Stora wrote:

> You are correct that R134a doesn’t contain chlorine as it is 1,1,1,2-Tetrafluoroethane.
> R12 does contain chlorine as it is Dichlorodifluoromethane
> However note that they both contain fluorine.
> Many tests would have a hard time checking for chlorine because of the fluorine being present.

R134A will _not_ produce a characteristic green color change in the flame test since it does not contain chlorine. In fact, the flame test is one of the recommended field tests for detecting CFC contamination in HFC refrigerant systems and it is commonly used to detect chlorine-containing adulterant gases in bulk R134A that arrives from overseas sources.

Irregardless of the wisdom of using junkyard-recovered gas in an A/C system, the original poster was asking about determining whether an unknown sample was R12 or R134A. A flame test in conjunction with a P/T test would go a long way in making that determination in the absence of expensive lab gear.

Some references:

Page 12: http://www.iicl.org/techcorner/bulletins/r134a_testing_procedures_1.pdf

Page 1: http://www.business.govt.nz/worksafe/information-guidance/all-guidance-items/hazard-management-bulletin-counterfeit-refrigerants-in-shipping-container-refrigeration-units/flame-testing

[Matt Colie]

Chris Tyler wrote on Sun, 07 December 2014 18:29

> Is there a test strip or some way to tell if the contents of a recycling tank is R12 or R134?
>
> Scored a Snap On refrigerant recovery system at a swap meet today for cheap. I will be happy if it simply functions as a vaccuum pump. However,
> the fellow said he had used it int the junkyard to recover R12 from older cars and the tank has quite a bit in it.
>
> My coach is R12 right now and funtioned when I got it a little over a year ago. It still has pressure but is low. I suspect a slow leak at the
> compressor. I would like to keep it R12. If i have to convert it I will go with duracool.It would be nice if the R12in the tank is usable given the
> cost. I know about the problems mixing the two [although several friends have done so with no problems for several years I dont want to risk that]
> so wondering if there was a way to tell what it is with any degree of certainty

Chris,

You have an interesting problem, but at the end of this you may choose a solution....
You cannot not easily detect R-134 contamination of an R-12 cache. The only thing easily tested for is the presence of chlorine. Testing for the
lack or proportion thereof requires significantly sophisticated testing.

Were I you, I would use it as is.
The reasons are simple...
When handling R-134, none of the standard access fitting match. Any normal person will have a difficult time locating and acquiring the adapter
fitting required to do this without changing the systems access fittings. Once the access fitting are changed then the PO of the recovery system
would not have been able to hook up that system to the vehicle. So, there is a very good chance that there is no R-134 in the R-12 tank.

By the by, the standard fitting for HC-12a are the same as R-134.

Matt


--
Matt & Mary Colie - Members GMCMI, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
SE Michigan - Twixt A2 and Detroit