Not according to this information. Only the four smallest filters are rated at 40mu. PL14610/14612(shorty), and PL14447/14476(shorty). IIRC, there is also an email from Puro to SuperBusa confirming that information.
PureONE Flow vs. PSID Data from Purolator
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Originally Posted By: chubbs1
This filter is not a 20 Micron filter. 99%@40um
If you are refering to the PL14006, it certainly is rated at 99.9% @ 20 microns. Look at the side of the box next time you are in a store that carrys PureOne filters.
This filter is not a 20 Micron filter. 99%@40um
If you are refering to the PL14006, it certainly is rated at 99.9% @ 20 microns. Look at the side of the box next time you are in a store that carrys PureOne filters.
Originally Posted By: hofcat
I use a Pure One myself on my Subaru Forester but the differential pressure across the filter data provided by Purolator is not what I would have been expecting. The problem I see is that data shows a pressure drop that is linearly proportional to flow rate when I would expect to see a pressure drop that is squared in proportion to flow rate increases. Google the “Darcy–Weisbach Equation” and select the Wikipedia link for the equation. The equation represents the head loss or pressure loss due to friction in a fluid system. This equation is commonly used for piping systems but it can be used to represent the pressure drop across an oil filter. The pressure drop across an oil filter should primarily be due to friction losses.
There are several terms in the equation.
L = Length of pipe
D= Diameter of pipe
g= gravity
f= Darcy friction factor
V= fluid velocity
H=Head Loss or pressure drop due to friction
For an oil filter the terms L, D, g, and f should be fixed or constants. This leaves fluid flow and pressure drop as the only variables. Notice that H increases as VxV or V squared. That means if you double the velocity, the pressure drop should be 4 times as great. The data provided by Purolator does not behave in this way.
The Purolator data show the pressure drop at 8 gpm to be 3.2 psid and at 16 gpm to be 7.6 psid. With a doubling of flow rate the pressure drop only increase by 2.375 times as much not 4 times as much. The predicted pressure drop should be 12.8 psid.
The Purolator data result might be explained if the terms, D or L where not fixed or constants. This would be the case if there was a bypass valve on the filter opening but this filter has no bypass valve. The other possibility might be the resistance to oil flow of the ant-drain back valve might change if it mechanically deforms or flexes as flow increase allowing a wider opening for oil to flow through. I would like to believe the good numbers provided by Purolator by my education in physics and fluid dynamics as well as experience operating nuclear power plants with lots of fluid systems makes me suspicious of the results. To believe them I would have to know more about the test set up or see the test myself. It may be possible I am missing something or making the wrong assumptions about the properties of the filter.
That famous graph showing the pressure drop across different brands of filters with the at different flow rates is also suspicious to me. The Fram ToughGurard pressure drop curve has the expected characteristics. Many of the others do not. The curves should look like a parabola turned on it side, not a straight line.
+1 To SuperBusa recommendation to ask Purolator to run a test on Purolator Subaru oil filter at Subaru engine oil flow rates.
Sorry, discovered this thread late.
I've not come across a filter element, or flow resistance curve for typical elements that operates under the (exponential) V^2. Exponential for sure, but not at the squared.
The curves shown for this manufacturer are pretty typical IMO...note just for an element not a system.
http://www.yamashin-filter.co.jp/eng/product/branch/3004/1197.html
Filters are usually the least restrictive part of the system.
I use a Pure One myself on my Subaru Forester but the differential pressure across the filter data provided by Purolator is not what I would have been expecting. The problem I see is that data shows a pressure drop that is linearly proportional to flow rate when I would expect to see a pressure drop that is squared in proportion to flow rate increases. Google the “Darcy–Weisbach Equation” and select the Wikipedia link for the equation. The equation represents the head loss or pressure loss due to friction in a fluid system. This equation is commonly used for piping systems but it can be used to represent the pressure drop across an oil filter. The pressure drop across an oil filter should primarily be due to friction losses.
There are several terms in the equation.
L = Length of pipe
D= Diameter of pipe
g= gravity
f= Darcy friction factor
V= fluid velocity
H=Head Loss or pressure drop due to friction
For an oil filter the terms L, D, g, and f should be fixed or constants. This leaves fluid flow and pressure drop as the only variables. Notice that H increases as VxV or V squared. That means if you double the velocity, the pressure drop should be 4 times as great. The data provided by Purolator does not behave in this way.
The Purolator data show the pressure drop at 8 gpm to be 3.2 psid and at 16 gpm to be 7.6 psid. With a doubling of flow rate the pressure drop only increase by 2.375 times as much not 4 times as much. The predicted pressure drop should be 12.8 psid.
The Purolator data result might be explained if the terms, D or L where not fixed or constants. This would be the case if there was a bypass valve on the filter opening but this filter has no bypass valve. The other possibility might be the resistance to oil flow of the ant-drain back valve might change if it mechanically deforms or flexes as flow increase allowing a wider opening for oil to flow through. I would like to believe the good numbers provided by Purolator by my education in physics and fluid dynamics as well as experience operating nuclear power plants with lots of fluid systems makes me suspicious of the results. To believe them I would have to know more about the test set up or see the test myself. It may be possible I am missing something or making the wrong assumptions about the properties of the filter.
That famous graph showing the pressure drop across different brands of filters with the at different flow rates is also suspicious to me. The Fram ToughGurard pressure drop curve has the expected characteristics. Many of the others do not. The curves should look like a parabola turned on it side, not a straight line.
+1 To SuperBusa recommendation to ask Purolator to run a test on Purolator Subaru oil filter at Subaru engine oil flow rates.
Sorry, discovered this thread late.
I've not come across a filter element, or flow resistance curve for typical elements that operates under the (exponential) V^2. Exponential for sure, but not at the squared.
The curves shown for this manufacturer are pretty typical IMO...note just for an element not a system.
http://www.yamashin-filter.co.jp/eng/product/branch/3004/1197.html
Filters are usually the least restrictive part of the system.
Originally Posted By: Shannow
I've not come across a filter element, or flow resistance curve for typical elements that operates under the (exponential) V^2. Exponential for sure, but not at the squared.
The curves shown for this manufacturer are pretty typical IMO...note just for an element not a system.
http://www.yamashin-filter.co.jp/eng/product/branch/3004/1197.html
Filters are usually the least restrictive part of the system.
In the link above, I believe the different curves on each graph are at different fluid temperatures. You can see that as the fluid temperature decreases and makes the oil thicker that the curve starts getting maybe closer to a V^2 function. Obviously the PSID at each flow rate goes up dramatically as the fluid becomes more viscous.
I'm wondering if the media opens up more when it's hot which changes its resistance at different temperatures and therefore skews the V^2 flow curve.
I've not come across a filter element, or flow resistance curve for typical elements that operates under the (exponential) V^2. Exponential for sure, but not at the squared.
The curves shown for this manufacturer are pretty typical IMO...note just for an element not a system.
http://www.yamashin-filter.co.jp/eng/product/branch/3004/1197.html
Filters are usually the least restrictive part of the system.
In the link above, I believe the different curves on each graph are at different fluid temperatures. You can see that as the fluid temperature decreases and makes the oil thicker that the curve starts getting maybe closer to a V^2 function. Obviously the PSID at each flow rate goes up dramatically as the fluid becomes more viscous.
I'm wondering if the media opens up more when it's hot which changes its resistance at different temperatures and therefore skews the V^2 flow curve.
THE MISSING PIECE:
Filter media area is "large" compared to flow rate:
200in^2 vs. 2320in^3/min works out to 0.05GPM/In^2 of filter media. Which hain't much, bro. And PureOne filters have a reputation for generally having much more than 200Sq.In of media.
Thus, thanks to a very large filter media area relative to flow rate, fluid velocities are "low" (like, less than 1 ft/min), and do not fluctuate much (like, all of 1 ft/min difference between min and max operating flow rates!).
MY POINT: Fluid velocities through filtration media is so low, and the changes are so small (relatively), that the pressure drop can be expected to behave like a kinetic friction model (such as a skidding car tire), which has a linear relationship between velocity and reaction forces. Non-linearities in filter pressure-drop curves will be more a result of construction other than filtration media.
At least, until the filter gets loaded up with dirt.
Filter media area is "large" compared to flow rate:
200in^2 vs. 2320in^3/min works out to 0.05GPM/In^2 of filter media. Which hain't much, bro. And PureOne filters have a reputation for generally having much more than 200Sq.In of media.
Thus, thanks to a very large filter media area relative to flow rate, fluid velocities are "low" (like, less than 1 ft/min), and do not fluctuate much (like, all of 1 ft/min difference between min and max operating flow rates!).
MY POINT: Fluid velocities through filtration media is so low, and the changes are so small (relatively), that the pressure drop can be expected to behave like a kinetic friction model (such as a skidding car tire), which has a linear relationship between velocity and reaction forces. Non-linearities in filter pressure-drop curves will be more a result of construction other than filtration media.
At least, until the filter gets loaded up with dirt.
Who makes ultraguard?
wonder where denso is in all this? high flow with no restriction, due to less fine filtering?
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