quote:Originally posted by Bob K.:
...With regard to ZDDP, I thought RPVOT should not be used on oils containing ZDDP - pressure drop affected by ZDDP/water decomposition gases...
Bob, RBOT has been used for ages in reliably assessing serviceability of turbine oils; for decades before any of the phenol and amine type of additives were ever introduced. Also, for long long time ZDTP was the only type of antioxidants used in blending process. If that is true, are you saying that the whole industry lived in a la-la land by naively trusting this analysis, for which you say that it is unreliable for oils with ZDTP?
Also, if Frank or others out there that use turbine oils blended with ZDTP, then why not you or somebody else tell him (and others in similar situation) that tracking amine-phenol ratios in such case might be rather marginal, because such oil might not have sufficiently broad base of these additives necessary for the serviceability evaluation? If there are no amine-phenol-based additives in his oil (or just small quantities being present), instead of amine-phenol ratio, what should he be tracking by RULER?