Feb 1, 2013 · We've used MP39 since the R-12 phaseout, same with HP80. Both work very well, with any oil in short coupled applications. 134A has been nothing but a nuisance with it's low capacity, and my habit has been to remove the 134A and replace it with MP39 when I do repairs on small equipment.

Mar 5, 2012 · MP 39 was a failure, I couldn't get the box below 25 degrees without starving the system for refrigerant and creating flash before the tev. Gonna reclaim and try out mp 66, as I have heard is the only low temp. replacement for r-12. After clearing the sightglass my suction psig at the compressor was around 16-20 which won't really do me any good.

Feb 21, 2007 · No doubt, MP-39 is one of the best replacements for R-12 in medium temp applications. But there is no such thing as a drop in for R-12, MP-39 is classified as a near drop in. The existing TXVs should be fine as long as they are …

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Apr 15, 2013 · MP39 (R404A) is an R12 interim service replacement refrigerant for medium temperature. MP66 (R401B) is the only one designed specifically for low temperature applications, and from my experience with it over the past 20 years, it does perform much better than MP39...or its cousins R409A and Hot Shot...but still not quite as good as R12.

Jun 16, 2008 · Check your oil for acid, check the TXV, and check out your oil type in the new unit, print the Dupont MP-39 page and take it with you. A half assed retrofit may have killed it to begin with, or the retrofit was fine, but the cause of the failure before that may not …

Have been using R-420 (RB-276) for the last three years. Had used MP-39 and R-409, both good, but again head pressure being a problem here in the warm areas. Have found that R-420 is a little lower head then the other two in equal temps. Have put it in ice cream/shake machines and POU's also walk in's. No problems to date.

May 3, 2014 · The unit had MP-39 written on the compressor and electrical cover. after hooking up gauges and checking superheat and sub cooling i believe it to honestly be MP-39 (R-401a) and i think it is overcharged. 26* sub-cooling 3* superheat.

Mar 24, 2010 · i added 3 ounces of Mp 39 and 1.5 ounces of R-22 "never tried this before" fired it up and it worked great, cycled off in less than 5 minutes i had to run, no time for any amp draws, the compressor was not getting hot at all i will keep ya posted anyone have a comment on why this worked or why is it gonna be a problem.

May 16, 2011 · Worked on an old R12 reach in other day. Med temp min oil. Fixed leak opted to use MP-39 instead of hot shot. Recall an old timer who told me he didnt like using hot shot. Other then hot shot seems to run slightly lower pressures at slightly higher pressures cant see any benefit. Is mp-39 more prone to with vapor leaks fracturization then hotshot?