R12 W/I freezer

[dave1234]

So it is pretty safe to say that if the condenser is outside the system usually would be desinged with 22 or a 502 (replacement nowadays) even with a means of head pressure control high side operating pressures would plummet in the winter. Im recalling hearing that once while working with a senior tech on a remote condenser with MP39 in the middle of winter.

[chilliwilly]

MO49 Plus has been "available" to us here in the States for a couple of years now, but unfortunately it is quite slow in becoming "readily available". Nobody is stocking it...at least where I'm located.

Thanks for the input on you experience with it, Martyn. I knew you had MO49 (R413A) for quite some time, but didn't realize until today while doing some searching about, that you folks have been switched to MO49 Plus (R437A) as well:

http://www2.dupont.com/Refrigerants/.../k10785_uk.pdf

Does this come as news to you too? I can no longer find any reference to R413A on the DuPont UK website. Hmmm?

As for the leaking seals, if you have been converting directly from R12 to MO49 then you should have no problem. The seal troubles exist because of the R22 component of most interim replacement refrigerant like R409A, R401A, etc. The R22 tends to swell the elastomeric seals. When you remove the R22 the seal then shrinks....and you've got a leak.

I haven't had any R12 stock for nearly 15 years.

Yes that is news to me, the stuff that I've got just says isceon 49 on the dumpy cylinders. Mind you I bought a job lot a few years back for £100.00, so I've had it a while. Might be the other stuff they used before they reblended it.

The R12 availabillity is something I only get to hear about every so often, and sometimes get the chance to buy it. When I don't have any I just decanter whats left of the R12 then replace with isceon 49. Then eventually when I get time, I just get the decantered R12, and fill it into a special dumpy and perform an insulation test on it.

I use a cylinder that I've modified that has a long electrode screwed into the top side of the bottle thats insulated from the rest of the cylinder. Then just do a 500 volt test between that and the dip tube, if I get a reading higher than 150meg I'm happy. If its say 100 meg or lower I know its suspect. And if its extremely low it stays where it is. I just re-decanter the better stuff using dryers till its some where near the 150 meg.

A long process, but when you don't have any of what you need, you have to scrape the bottom of the barrel.

[icemeister]

Yes that is news to me, the stuff that I've got just says isceon 49 on the dumpy cylinders. Mind you I bought a job lot a few years back for £100.00, so I've had it a while. Might be the other stuff they used before they reblended it.

The change appears to have taken place within the last 6 months. From what I know, the difference between R413A and R437A is minimal. I believe they tweaked the hydrocarbons content to pass the US flammability regulations.

[james122964]

Wasn't R12 the chosen refrigerant for domestic refrigerators for decades? Given their design (evap in freezer only), I suspect they all would've run in a vacuum as well. Nowadays I wig out if a see a system doing that.

As a side note, I've come across entirely too many converted systems where you don't know what's in them, so I've had to figure it out through investigation...OR just pull it, charge it up and LABEL IT prominently for the next guy.

I have been putting up with a lot of unmarked systems lately. I guess thats one way to keep your customers, do not tell them what you put in the system so no one can work on them without charging you for recovery and disposal.

Jim

[chilliwilly]

OOOOOH naughty boy.

[MaxPF]

MO49 Plus has been "available" to us here in the States for a couple of years now, but unfortunately it is quite slow in becoming "readily available". Nobody is stocking it...at least where I'm located.

Thanks for the input on you experience with it, Martyn. I knew you had MO49 (R413A) for quite some time, but didn't realize until today while doing some searching about, that you folks have been switched to MO49 Plus (R437A) as well:

http://www2.dupont.com/Refrigerants/.../k10785_uk.pdf

Does this come as news to you too? I can no longer find any reference to R413A on the DuPont UK website. Hmmm?

As for the leaking seals, if you have been converting directly from R12 to MO49 then you should have no problem. The seal troubles exist because of the R22 component of most interim replacement refrigerant like R409A, R401A, etc. The R22 tends to swell the elastomeric seals. When you remove the R22 the seal then shrinks....and you've got a leak.

I haven't had any R12 stock for nearly 15 years.

Hey Ice, my local DuPont distributor doesn't even have any of the ISCEON products listed in their system. Apparently, everyone is still using MP39 and MP66 and ignoring the upcoming debacle. Anyway, my question is: what did you pay for a 30 pounder of the stuff?