I believe VI improvers are added to the base oil, which is a 40 weight, primarily to improve cold weather flow. 10W isn't a reference to the weight of the oil, rather a measure of the energy required to crank an engine at cold temps.
Amsoil Eao before and after Particle counts
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My bad, I was thinking of Pour Point Depressants!
George, the only way I see you could have problems with filtering oils with VIIs is at lower temperatures where an interaction between contaminants, water and the VIIs caused them to clump together into much larger particles. However, once the oil warmed above room temperature, the VII should go back into solution. But again, we should be seeing this problem even with 15µ filters as I find it highly improbable they would clump to just a maximum size of 5µ and stop.
Gary might actually have come up with a good idea to test for this. Only it might be more informative to also test well used oil too.
Gary might actually have come up with a good idea to test for this. Only it might be more informative to also test well used oil too.
I had never had any issues with VI stripping with 12 micron beta 1000 filters. It was only when I went to the 3 micron Beta 1000 that the "out of grade" began to appear. Backed off to 6 micron beta 1000 and the fluids stayed in grade.....
Again, I am talking about "real" absolute microglass filters that are rated to not only ISO 16889 but to varying flow/pressure ratings. These are not paper or cellulose/glass combo units..
I could care less about "proving" my assertions. You can accept the information or disregard it. I am just sharing real world experiences that I, like you, had no expectation of occurring..
I now know what I can and cannot do with respect to ultra fine filtration of VI improved fluids.
The problems simply have not surfaced in that there are so few true George Morrison, STLE CLS
Again, I am talking about "real" absolute microglass filters that are rated to not only ISO 16889 but to varying flow/pressure ratings. These are not paper or cellulose/glass combo units..
I could care less about "proving" my assertions. You can accept the information or disregard it. I am just sharing real world experiences that I, like you, had no expectation of occurring..
I now know what I can and cannot do with respect to ultra fine filtration of VI improved fluids.
The problems simply have not surfaced in that there are so few true George Morrison, STLE CLS
Thanks for the info George, always good (and appreciated) to have input from those in the know!
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Well, you may not need validation for your own sake, George. Why prove something to yourself that you already know? However, for everyone else I'm sure that they would like to see some other data points to accept this radical departure from current lubrication conventions of thought. This in no way impugns your work.
Now I do wonder about 427's suggestion that there's some other action ..like floculation occurring. This certainly can and does occur in many chemical processes. One clarifying polymer that we used was of a long chain type with a high molecular weight (whatever the heck that had to do with it - I dunno
). But that involved polarity differences that forced a bunch of low Ph strands to take a right angle hike from each other and have all the suspended particles latch on to them.
But ..it would be nice to get a lab report of such an occurrence, imo.
427Z06: When Kristin gets back to me, I'll requery her on both virgin fluid and used. This really shouldn't be as expensive as a UOA. It's just an intermediate short process to filter oil ..or so I reason. Then again, I'm not reasoning the cost.
Now I do wonder about 427's suggestion that there's some other action ..like floculation occurring. This certainly can and does occur in many chemical processes. One clarifying polymer that we used was of a long chain type with a high molecular weight (whatever the heck that had to do with it - I dunno
But ..it would be nice to get a lab report of such an occurrence, imo.
427Z06: When Kristin gets back to me, I'll requery her on both virgin fluid and used. This really shouldn't be as expensive as a UOA. It's just an intermediate short process to filter oil ..or so I reason. Then again, I'm not reasoning the cost.
Part of the problem here George is we started talking about full-flow engine oil filters usually rated under ISO 4548-12 for absolute efficiency, Beta 75, and as the discussion progressed you're now up to Beta 1000 filters.
Generally for filters to achieve a 3µ rating at Beta 1000 in this type of service, they'll be removing 90% of the particles 3 times smaller. At 50% efficiency, we might be talking another 3 times smaller, so now your down to .3µ and we start approaching the size of the largest polymer molecules. Throw in some glocculation and we may now have a mechanism for what you observed.
But when we get back to the practical side of the equation, I'll stand by my original assertion that declaring the limit for practical oil filters at 6µ for an absolute efficiency, Beta 75 may be a bit large. As someone already pointed out, they already make and sell 3µ absolute rated hydraulic filter elements and they carry no warning that they'll strip out VIIs.
Gary, it would be fascinating to see your proposed tests carried out.
Generally for filters to achieve a 3µ rating at Beta 1000 in this type of service, they'll be removing 90% of the particles 3 times smaller. At 50% efficiency, we might be talking another 3 times smaller, so now your down to .3µ and we start approaching the size of the largest polymer molecules. Throw in some glocculation and we may now have a mechanism for what you observed.
But when we get back to the practical side of the equation, I'll stand by my original assertion that declaring the limit for practical oil filters at 6µ for an absolute efficiency, Beta 75 may be a bit large. As someone already pointed out, they already make and sell 3µ absolute rated hydraulic filter elements and they carry no warning that they'll strip out VIIs.
Gary, it would be fascinating to see your proposed tests carried out.
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Good point. I naively thought of a 6um filter as having the lower limit with a sharp cutoff. There would have to be some variation ..with some +/- distribution to achieve the higher beta numbers. I imagine even the finer synthetic medias vary a bit in pore size.
I think a PM/email into Schultz may help here. I'm sure PALL has some stuff in their ditty bag of tricks to filter to the zizzle level. He might be able to either filter the sample(s) or provide the media
I think a PM/email into Schultz may help here. I'm sure PALL has some stuff in their ditty bag of tricks to filter to the zizzle level. He might be able to either filter the sample(s) or provide the media
Another good idea Gary.
Schultz just measured an AMSOil Ea0 filter 4548-12 rated 15µm absolute efficiency (Beta 75) and found the largest pore was 30µm, and the smallest pore was 10µm.
Who's got some 3µm Beta 1000 media on hand?
Schultz just measured an AMSOil Ea0 filter 4548-12 rated 15µm absolute efficiency (Beta 75) and found the largest pore was 30µm, and the smallest pore was 10µm.
Who's got some 3µm Beta 1000 media on hand?
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Well, the cost of this test puts it out of my league
Here's Blackstone's response to my query:
Gary: Thanks for the e-mail. Kristin passed this on to me because I'm the guy to talk to about this kind of stuff. In answer to your question, yes, we can do this type of filtration/viscosity work. I have 5 um filters on hand, so if you want to use this, that would save a little money. In addition to the high temperature viscosity, you may also want to run a low temperature viscosity and then get a viscosity index on the before and after samples. You will have to supply the sample. Our standard price for a low temperature and high temperature viscosity plus the viscosity index is $30.50/sample and I will do the 5 um oil filtration for an extra $75.00. Let me know if this is acceptable and I'll get the apparatus set-up.
Sincerely,
Ryan Stark
Blackstone Labs
I had visions of a tech selecting a circular fine paper filter ..placing it in a funnel shaped porcelain open toped container that was stuck into a graduated receiver that had vacuum applied to it. Measure resultant contents after heating (a minor part of a $20 UOA)
For that matter allow gravity flow while doing 25 other lab tasks.
But apparently this is a more complicated procedure
In all fairness ..it appears to be more of a "well, we have to charge you a decent amount ..just for the oddity of it ..but we'll throw in enough added value to justify it" type thing. That is, before and after high:low temp visc to determine any alteration in VI ..etc.
Here's Blackstone's response to my query:
Gary: Thanks for the e-mail. Kristin passed this on to me because I'm the guy to talk to about this kind of stuff. In answer to your question, yes, we can do this type of filtration/viscosity work. I have 5 um filters on hand, so if you want to use this, that would save a little money. In addition to the high temperature viscosity, you may also want to run a low temperature viscosity and then get a viscosity index on the before and after samples. You will have to supply the sample. Our standard price for a low temperature and high temperature viscosity plus the viscosity index is $30.50/sample and I will do the 5 um oil filtration for an extra $75.00. Let me know if this is acceptable and I'll get the apparatus set-up.
Sincerely,
Ryan Stark
Blackstone Labs
I had visions of a tech selecting a circular fine paper filter ..placing it in a funnel shaped porcelain open toped container that was stuck into a graduated receiver that had vacuum applied to it. Measure resultant contents after heating (a minor part of a $20 UOA)
But apparently this is a more complicated procedure
In all fairness ..it appears to be more of a "well, we have to charge you a decent amount ..just for the oddity of it ..but we'll throw in enough added value to justify it" type thing. That is, before and after high:low temp visc to determine any alteration in VI ..etc.
Which brings up the point I previously discussed and that is varying flow rate. Filters that are rated at a 3 micron beta 200 via ISO 16889 would not achieve this rating in a varying flow rate: i.e. the real world of full and even by-pass filtration.. So Pall's 3 micron beta 200 would not meet this specification in real world automotive (and truck) flow conditions.. Most likely have to be in the 10/12 micron region, even for a full glass element..
When we speak of "absolute", we normally are talking beta 200 level. Beta 75 would be accorded "nominal".. Which relates to most paper/cellulose membranes..
And the varying flow rate is what crossed the bridge for me: finally a filter was available with a 3 micron beta 1000 rating under ISO 16889, but also was a beta 200 with the new varying flow rate test method add on to 16889... Which is where my problems began with stripping.
And no, Pall and other manufacturers do not have to put a "WARNING, will strip VI improver" as VI improvers are not used on the fluids these filters are used with. Hydraulic oils, circulation oils and industrial gear oils do not contain VI improvers so filtering down to even 1 micron is no issue whatever..
George Morrison, STLE CLS
When we speak of "absolute", we normally are talking beta 200 level. Beta 75 would be accorded "nominal".. Which relates to most paper/cellulose membranes..
And the varying flow rate is what crossed the bridge for me: finally a filter was available with a 3 micron beta 1000 rating under ISO 16889, but also was a beta 200 with the new varying flow rate test method add on to 16889... Which is where my problems began with stripping.
And no, Pall and other manufacturers do not have to put a "WARNING, will strip VI improver" as VI improvers are not used on the fluids these filters are used with. Hydraulic oils, circulation oils and industrial gear oils do not contain VI improvers so filtering down to even 1 micron is no issue whatever..
George Morrison, STLE CLS
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Okay ..sure. The inability to operate in a variable flow rate wouldn't discount the filtration level of a given media in an appropriate flow rate environment. That is, if you want to duplicate VII stripping, you don't need a 3um beta 1000 media. You just do it at a constant and slower flow rate. Agreed
Normally when we speak absolute ..we're talking Beta 75 ..however for the sake of this discussion, in this minute fineness of filtration ..I'd willingly adapt to moving beta 75 up to beta 200. We're talking the difference between 98.6 and 99.5 ..or slightly less then 1 particle out of 100 in comparison of the spec'd size or greater. ..or 9 more particles per 1000 (if I'm figuring correctly).
I see your point about lower visc fluids. They may not have any VII to strip out of the fluid.
Normally when we speak absolute ..we're talking Beta 75 ..however for the sake of this discussion, in this minute fineness of filtration ..I'd willingly adapt to moving beta 75 up to beta 200. We're talking the difference between 98.6 and 99.5 ..or slightly less then 1 particle out of 100 in comparison of the spec'd size or greater. ..or 9 more particles per 1000 (if I'm figuring correctly).
I see your point about lower visc fluids. They may not have any VII to strip out of the fluid.
"Who's got some 3µm Beta 1000 media on hand?"
I do. I've got membranes of UF,.02,.2,.45,.8, 1, 3, 5µm. These would be the 99.99% type membranes (not medias) at the rated pore size.
I'm not sure of the Chemistry side of things and how large a VI molecule is but a 3µm molecule is huge. My theory would be the VI is precipitating out of solution when cold and then filtered? However, if this were the case it would redissolve once the oil was heated, but there may be exceptions to this with certain organics. Some things once denatured don't go back into solution the same. If this were the case it would remain in the filter and not get ground back up by the engine that uses a larger pore filter. Perhaps there is a coalescing effect going on???
To test VI removal theory from oil I would imagine you could measure the surface tension or measure viscosity by timing the oil flowing through an orifice after filtration through various membrane filters. The orifice doesn't have to be an industry standard orifice, it could be one created by a needle valve, we're just looking for differences after filtration not classifications.
I did ask an R&D guy in our industrial group and he said he would get back to me, but he wasn't aware of it. I'll also ask around some more to see what others have to say. It was interesting that he did bring up other problems with fine filtration of oils was static discharge. They have found that the arcing in the the filter housing can blow holes in the glass media.
Right now I really don't have the time, I'm in the middle of a couple product launches. I haven't even finished the EAO flow testing yet. I could loan a 25mm filter holder and membrane die cuts to someone willing to do the rest of the testing. Otherwise it would be month before I could do it.
I do. I've got membranes of UF,.02,.2,.45,.8, 1, 3, 5µm. These would be the 99.99% type membranes (not medias) at the rated pore size.
I'm not sure of the Chemistry side of things and how large a VI molecule is but a 3µm molecule is huge. My theory would be the VI is precipitating out of solution when cold and then filtered? However, if this were the case it would redissolve once the oil was heated, but there may be exceptions to this with certain organics. Some things once denatured don't go back into solution the same. If this were the case it would remain in the filter and not get ground back up by the engine that uses a larger pore filter. Perhaps there is a coalescing effect going on???
To test VI removal theory from oil I would imagine you could measure the surface tension or measure viscosity by timing the oil flowing through an orifice after filtration through various membrane filters. The orifice doesn't have to be an industry standard orifice, it could be one created by a needle valve, we're just looking for differences after filtration not classifications.
I did ask an R&D guy in our industrial group and he said he would get back to me, but he wasn't aware of it. I'll also ask around some more to see what others have to say. It was interesting that he did bring up other problems with fine filtration of oils was static discharge. They have found that the arcing in the the filter housing can blow holes in the glass media.
Right now I really don't have the time, I'm in the middle of a couple product launches. I haven't even finished the EAO flow testing yet. I could loan a 25mm filter holder and membrane die cuts to someone willing to do the rest of the testing. Otherwise it would be month before I could do it.
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Interesting phenomena with the static discharge
One wouldn't normally associate such a electro-chemical event when thinking of filtration. I am thankful that such events are detected and the origins determined. You've got to love the information age and the unique access that we have to this type of information.
I'd feel more confident with you handling the filtration end of it ..on your timetable. If you want to opt out of the viscosity determination ..I'll spring for Blackstone (or any other lab) to do the testing.
Thanks for chiming in on this, Tim. I would surely like to hear what your R&D industrial person has to add to this (and anything else he has to offer - that static discharge tidbit was priceless in novelty).
I'd feel more confident with you handling the filtration end of it ..on your timetable. If you want to opt out of the viscosity determination ..I'll spring for Blackstone (or any other lab) to do the testing.
Thanks for chiming in on this, Tim. I would surely like to hear what your R&D industrial person has to add to this (and anything else he has to offer - that static discharge tidbit was priceless in novelty).
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One thing that has that little voice twitching in my "other self's" head here. Now being a firm believer in the assertion that there are no stoopid questions ..except those that don't get asked ...
How long is an uncoiled VII molecule? How far is its span? (I don't have a clue
)
How long is an uncoiled VII molecule? How far is its span? (I don't have a clue
The static discharge issue is huge when filtering jet and diesel fuels. Jet fuels are additized to address this issue. Some microglass elements are more prone to static than others due to the support design. Some manufacturers use a plastic mesh reinforcement which is very prone to static, while the stainless steel reinforced microglass elements do not seem to be affected by static build up. I have walked into filtration rooms with the lights out and St. Elmo's Fire was evident on all the filter canisters! An eerie feeling, especially in a Nuclear Plant!
The VI stripping occurred at elevated/normal machine operating temperatures. Which is when VI improvers are at their maximum size...
George Morrison, STLE CLS
The VI stripping occurred at elevated/normal machine operating temperatures. Which is when VI improvers are at their maximum size...
George Morrison, STLE CLS
You mean to tell me Filter Guy lead me astray?
The two most popular reported media ratings are a nominal micron rating (50%)
and an absolute micron rating (98.7%).
http://www.filtercouncil.org/techdata/tsbs/89-5R3.pdf
Quote:
How long is an uncoiled VII molecule? How far is its span? (I don't have a clue)
First, polymer molecules are a distribution of sizes, so the largest ones are very, very few in number. At room temperature the largest common polymers are hundredths of microns at the most. I'd have to go back and run some calcs at higher temps, but a SWAG would be that they may quadruple or increase by a factor of ten in length. But again, the largest ones are very, very few in number.
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Okay ..I was just seeing lots of squished up strings passing through cold ..but uncoiling and getting snagged when hot. Obviously the proportion of scale is still in the very ..very... small category. It's equally apparent that virtually no particles will be spherical either.
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