Bob K.,

Thank you much for jumping in and offering help to Frank. Especially, because the RULER is “your baby”, which makes you being the right person to do it. He appears very enthusiastic and is trying to do the right thing, but seems slowly getting lost in trying to find ways to interpret RULER result. I think that folks at the lab that Frank was using obviously did not do much for him, except sending him dry test data. Is it my impression that they don’t know much about it, except just running the RULER analyzer.

As I mentioned before, (some folks wouldn’t believe it!) we have some oils that are “older than dirt” (some are 40+ years oil and still in service). More typical age is 25-30 years in service. How authentic those oils are it is hard to tell, because our folks added a lot of make up oil to it during those years (somebody shout SWEETENING). We also have powerhouses running new Group 2 oils, too (the ones that changed their turbine oil in the last 10 years). So, of course, we still have some oils with ZDTP in it. Do we have phenolic-based additives too? It could very well be the case, because we added over the years make up oils that may have had these types of additives. Unfortunately, I could not be more specific because I am not a blender nor have I ran RULER or mass spectrometer to check it out. However, we simply relied on RPVOT in combination with other characteristics to assess remaining service life of our R&O turbine oils. It has been working flawlessly and reliably so far, and for that reason I am not “hot” about RULER at this time. By the way, we have approx. million and a half gallons of turbine oil in our powerhouses.

Here's a case of RPVOT vs Ruler trivia for you all....our customer has a steam turbine using XXXXX oil, which is a high qualtiy and great oil for this application. A few accidents took place, involving massive amounts of water being dumped into the oil, but the water was succeffully filetered and cleaned out.

Our routine oil analysis after the accidents, included Ruler for this unit, and we pointed out the total premature depletion of the phenolic additive, suspecting water washing as the culprit. FTIR analysis also showed no phenols in the oil. An oil sample was promptly dispatched to the oil companies' lab, who sent back an RPVOT result and said don't worry, all is fine, "what do indepentent labs know, we made the oil, we are king here !!" (and it is good to be King 'Mel Brooks')

I think here is the point that most folks are missing; that a good RPVOT result, by itself, does not mean milk and cookies !!! Even if you are the King !!

We advise the owner, that our opinion was firm about changing the oil. The steam turbine owner still had a basic trust of our relartionship, and asked the oil supplier to further prove the oil was good. The oil supplier then did some demulsibility testing and lo and behold, their tune has changed 180 degrees and now they are in agreement with us that the oil has to be changed, and soon !!

My point is....So what if RPVOT was fine? RPVOT is not the final arbiter of oil quality or service life.

The water washing prematurely screwed this good oil up, and affected other oil properties, one property which is extremely important in a steam turbine.

Andy Sitton (humble knave)

I am a novice in the oil analysis world so forgive my basic question that is: what is the difference between AN, BN and Ruler and what is best for what oils, or does it depend on your oil type?

quote:

Originally posted by Andy_Sitton:
Here's a case of RPVOT vs Ruler trivia for you all....

EUREKA! I solved the trivia! The answer is: "If anyone have oil problem, contact Andy Sitton, cous' HE IS THE KING". And we all should just ignore whatever oil conpanies' labs are telling us, because they are just a bunch of boneheads! Correct?

quote:

Originally posted by Andy_Sitton:
I think here is the point that most folks are missing; that a good RPVOT result, by itself, does not mean milk and cookies !!! Even if you are the King !

I think this is baseless assumption, because majority of folks on this board handle lubricants or lubricating issues on a daily basis, and they are certainly aware of the point that you are trying to make. I wish you would show a bit more respect to them (myself excluding). Personally, if RPVOT test shows the remainder of antioxidants of below 25% in my oil – I am changing it, regardless what would KING come up with his RULER.

Also, nobody that I am aware argued here that if RPVOT is OK than the oil must be OK. Or maybe I misread the tread?

This message has been edited. Last edited by: John Micetic,

Bob
The oil was last changed in 2003 and the RULER tests started in 16/7/2007 when we notice a drop in RPVOT=107 or 34%
It's a steam turbine, and the oil contains 85 ppm of zinc when new.
New oil is very light in colour like straw (not green.
Demulsibility new=41-37-2(20)current=40-40-0 (30)
Foam
-sequence I =300-0 current=440-5
-sequence II =10-0 current=30-0
-sequence III=70-20 current=480-10

Are you saying that the amine is removed by the Kleentek oil cleaner?
Frank

This message has been edited. Last edited by: macabf,

No, John, I am not saying I am the King...I was quoting comedly from a Mel Brooks movie....sorry for trying to break up the seriousness and animosity of the tone...I am hereby out of this message board chat...satisfied?

Frank
Couldn't get on-line yesterday, our IT personnel installed some new patches Wednesday nite - create 2 problems for everyone they fix. good way to ensure job security
As far as I know Kleentek or any other filtering system, electrostatic or physical doesn't remove soluble additives such as amine or ZDTP. However, if you have polar sludge, the polar alkyl amines will coat the sludge and thus be removed from the oil when the sludge is removed.
Trib. Trans. 47 pp.111-122, 2004 Yano,Watanabe, Miyazaki, Tsuchiza and Yamamoto, "Study on Sludge Formation during the Oxidation Process of Turbine Oils" ran 20 different turbine oils with dry TOST at 90 and 120C, pulled samples at set time intervals, ran RBOT and sludge (couldn't find pore size). Two oils had ZDTP. Rest phenol and/or amine based. Oil C had RBOT 350 hours, ZDTP, 1400 S and 59 ppm Zn. Oil F had 595 RBOT hours, 600 S and 59 ppm Zn. Authors stated ZDTP had poor sludge resistance - exceeding their sludge parameters when RBOT life was still 70%. They found sludge was primarily Zn sulfate. Oils C and F sound similar to yours and their research would help explain why Zn levels drop with usage - not sure why your sulfur went up. Would think alkyl amines would be attracted to Zn containing sludge.
I am still puzzled as to why ZDTP would be used in turbine oils but stand corrected.

JonnyC
Basically during use, antioxidants in oil deplete, when antioxidants reach around 10 - 20% of original concentration, oxidation accelerates and carboxylic acids (AN)accumulate and oil basestock starts to polymerize (viscosity increase/varnish formation).
In combustion engines, the oils contain additives (BN)to neutralize combustion gases. Some high temperature hydraulic fluids also have additives to neutralize strong acids from additive decomposition - basically independent of oxidation. So BN is only useful in systems that create strong acids.
RULER is an on-ste instrument that primarily measures antioxidants - FTIR, LC and other laboratory methods also available.
AN/BN are usually done by titration on-site or in lab although RULER and FTIR non-titration methods also for AN/BN.
The time from when the antioxidants deplete until AN increases is application dependent. The higher the operating temperature, the shorter the time until AN exceeds limits. So for low temperature applications with big oil reservoirs, the time between antioxidant depletion and AN increase can be months/years. For higher temperature systems, the time between depletion and AN increase can be days.
As with any oil condition trending program, you have to develop some history to understand the degradation mechanisms so that you can determine which technique is of most value. RULER is predictive/can detect abnormal conditons early on (once antioxidant depletion rate established can extrapolate to predict future readings such as when the oil will break)while AN is reactive (can't predict when oil will break)has been around for a very long time and most applications have well established limits for safe usage although recent changes in basestocks and antioxidants are requiring that some established limits and capabilities of other techniques be revisited.

Bob K.
You're a star. Thank you very much for the info.

All
I have notice that the Kleentek oil cleaner has actually lowered the TAN from 0.31 to new oil condition of 0.24 has anyone an explanation for it?
Frank

Various papers state that varnish contains carboxylic acids so varnish removal would be expected to lower TAN.
Just curious, what type of repeatability do you have on your TAN measurements?

Hy John,
I`m looking for materials who talk about TOST, RPVOT, and what test is more representative. I used in my hydraulic system the Mobil DTE 26 but some friends think Tellus 68 is best. Can you help me?
Thank you!