My predessor had RPVOT ran on a compressor oil.

It came back at 45 Minutes.

The oil is Virgina 300, which is repackaged Suniso 4GS.

No one at either company knows antyhtng about RPVOT.

I chacked my Mobil reference and they don't list RPVOTs for most oils.

So my question becomes, is RPVOT valid for all applications?

Refrigeration systems are oxygen free for the most part. Oxidative stability is not a major concern for these oils. Flow at low temperature, solvency for refrigerant and assembly process impurities, and lack of wax-like compounds and chemically reactive impurities are the key features needed.

When acidity is seen in these oils, it is most often a result of refrigerant breakdown generating halogen acids. Organic acids are not normally formed from the breakdown of mineral based lubricant.

RPVOT is not a useful test for these products. I'm not surprised the seller of the oils had no idea what you were talking about. In the ASHRAE 99 standard for description of refrigeration oils, RPVOT is not mentioned.