I am with Jason on this; there is no reason not to run a final filter that gives you micron ratings smaller than the smallest tolerances of our injectors and for that matter the smallest you can reasonably find even if its below that. Fact is newer systems are requiring 3ums (micron) primary filter performance. @ stage filtration is now a norm. Only makes sense as you do not want to clog one filter up quickly and why if makes no sense to run a pre and post pump filter with the same mic ratings if they are absolute ratings.
The very best water fuel sep micron rating I have been able to find are put out by Donaldson and IIRC also Champion under there retail arm Luber Finer. I would add CAT to that list as well. The issue I have with them is they are so tight lipped about their filter performance to the point of it being ridiculous or maybe I just have bad luck:doh:. With the various ways perf is rated and by what specs seems to get their panties in a wad over it. I tend to think its because they test better one way and not another. Regardless IMO based on a good amount of research have concluded Donaldson is the leader when it comes to filter tech in the industry with Champion/Luber Finer up there as well.
I no longer, with the new testing specifications, have seen a 2 mic Water/Fuel separator or for that matter any fuel filter, that I am aware of, that has a 2mic absolute rating 99%+. The ones you tend to see out there like the Baldwins are almost always a nominal rating. I do know that a number of the filters do and have ratings under the old single pass testing @ 2 mics. In speaking with the techs these filters still do perform as such. If you really nice and respectful yet keep pestering them
imp: they will cough up some of the single pass specs but I am not aware of any being published publicly.
Now I do know of a number 3 micron 99% absolute water fuel sep as well as normal fuel filters that are from Donaldson. Anyone you see with a 3mic rating for 99% would be a 2mic under the old testing protocols as far as I can tell so you can consider that. I know this at least with a few for sure as the primary filters below I recommend I have old docs from Donaldson that show them to be 2mic rated@99%. Link with info on filters current filter and flow ratings down below.
The issue IMO is going to be finding filters that match the flow rate in a water sep that has that low of a micron rating. Almost all are made to go as a part of a 2 filter setup and as such are not rated that low. Only the smaller flowing ones are. They likely will work for the flow capacity I personally prefer to have a good bit of room on filter size and the larger the longer between changes and less it might effect pressure as it fills. Its no issue with the final primary filter as they can be found in sizes up to 250 gph with under 1 psi bp@100psi. its only if someone is trying to do a all in one and wants that pressure. They could make one obviously. Its IMO there is not a need commercial for one. but most will do fine just not someone running a larger fuelab or dual walbros etc..
An example of the nominal ratio to absolute ratings. Here is a popular filter Baldwin BF1212 It has a rating of 4 mics nominal and its 20 micron absolute. Many will advertise the nominal ratings as they look great and everyone is always looking for the lowest numbers ........
The Dahl filter is popular marketed 2 mic but it to is nominal for its actual media filter perf. If you want the numbers for those I can pull them for you as well.
If you guys want a good read on fuel filter performance etc Donaldson has some good tech articles here is a decent one
http://www.donaldson-filters.com/070616.pdf This is also a GREAT document for assisting anyone looking to find a filter based on perf for their application
Something to consider is that looking at the spread ratio between nominal and absolute. If a absolute is catching 2-3 microns think about the size its caching @ the 50-60% single pass nominal rate... can you say 1 mic maybe even sub mic.:thumbup:
Basically if its made to filter without water sep the same media can be used with water sep as well so........
For dual filter setups with a pre and post pump setup these are the ones I typically recommend as it makes a balance setup. These are based on fitting the very popular filter bases used from NAPA and Baldwin:
* Napa 4770 (2 inlet and 2 outlet ports) 1-14 filter stud, 1/2" NPT ports
* Baldwin FB1311 (one inlet and one outlet port) 1-14 filter stud, 10 AN/JIC (same as 7/8-14 UNF) ports.
For the Water/Fuel Separator filters (between tank and pump):
Donaldson:
P551001 is a 7.35" L and 10 mic @ 99% 100 GPH recommended flow capacity
P550901 9.04" L @ 7 mic@99% 120 GPH recommended flow capacity
Both water separating performance ratings are as follows:
SAE J1488 Emulsified: 95% efficiency
SAE J1839 Free Water: 95% efficiency
Dahl type filters with depressurizing cones etc.. which is around 99%.
BTW with biodiesel becoming more widespread and in use this IMO is a real issue in water sep performance
http://www.donaldson.com/en/engine/support/datalibrary/053491.pdf It also details how water sep works.
Primary Fuel Filters (Donaldson):
* P551313 6.87" L 2 mics@99% 100 GPH recommended flow capacity @ up to 100psi fuel pressure for a max of 0.2 psi drop
* P551311 9.17" L 3 mic@ 99% 160 GPH recommended flow capacity @ up to 100psi fuel pressure for a max of 0.2 psi drop
These are there min ratings in speaking with a Donaldson tech many may test better but this is what they are "Rated" and tested to perform at.
Unless clearance is an issue I almost always recommend the:
* P551311 9.17" L 3 mic@ 99%
* P550901 9.04" L @ 7 mic@99%
with the following filter Bases for each:
Baldwin FB1311 (one inlet and one outlet port)
The reason for this is the NAPA filter bases QC has been hit or miss from lot to lot in terms of the sealing surface not being flat and leaking. Further they use 1/2 NPT ports which can run the risk of getting worn out and are not a standard JIC/AN thread like we tend to use on all the rest of the system. The each inlet and outlet is nice for dual pump setups except they are on the same sides which then requires 180 degree turns or more angles and mounting positions to get a clean install. The Baldwin has had good quality the inlet and outlet are standard 10 jic/an ORB fittings. I have found
this place offers a good price but maybe someone else knows of a better price. Prices everywhere have gone up over the last couple years but still good.
I did a post on filter performance and how to read and translate the various standards over on PSN
Filter Performance
Now if you want to open it up to larger spin on Filter bases then there are other options in the same performance range with larger filters. But for the flow rates most one here are using these match the systems the best and offer easy to mount without clearance issues. If you are going to be flowing 150-200 gal per hr then its a matter of a larger center stud port and larger filter diameter and usually OAL But the point is you are still dealing with the same filter media perf and flow rate becomes an issue of surface area (filter size)
Here is a number of Filters from Donaldson that are a minimum of 3 mic 99% filtration performance. I will denote Fuel Water Separation with: "FWS"
* P551312 3 mic@99%@gph 3.68Dx9.43L 7/8-14 Stud
* P550774 3 mic@99%@gph 3.66Dx6.85L 7/8-14 Stud
* P551315 3 mic@99%@80gph 3.15Dx6.93L 7/8-14 Stud
* P556917 3mic@99%@100gph 3.66Dx6.85L 13/16-12 Stud
* P553203 3 mic@99%@90gph(FWS) 3.66Dx7.61L 1-14 Stud
* P553207 3 mic@99%@100gph(FWS) 3.66DX8.64L 1-14 Stud
* P553213 3 mic@99%@90gph(FWS) 3.66Dx7.61L 1-14 Stud
* P553217 3 mic@99%@90gph(FWS) 3.66Dx8.64L 1-14 Stud
* P551313 3 mic@99%@100gph 3.68Dx6.95L1-14 Stud
* P551311 3 mic@99%@160gph 3.68Dx9.43L 1-14 Stud
* P550625 3mic@99%@180gph 3.70Dx10.75L 1-14 Stud
* P553500 3mic@99%@220gph 4.66Dx11.73L 1 5/8–12 Stud
* P551316 3mic@99%@250gph 5.34Dx12.19L 1 3/8-16 Stud
There are a good number if you want to look at filters 5-10 mics absolute which is still better than a typical 2 mic nominal.
I have also found oil filters that offer very good full flow performance (10 mic absolute) as well as offer a full extra quart of oil capacity yet still fit in the factory location.