Diesel Fuel Filter System

[Iambe]

My primary fuel filter on my Lehman engines are Racor's with 10 micron filters. The Double secondary filter cans are Baldwin BF825's and are 8 micron at 50% efficiency. I have been told the secondaries should be 2 micron. I have been unable to find any filters with this rating for the secondaries. I was thinking of replacing the double bank with a Racor but have been told they don't work well under pressure from fuel lift pump. I know I could put 2 micron Racor's in the primary but I've been told they could plug up easily
Would appreciate any comments on this.
I was thinking I could put a second Racor in series with the Primary Racor to get to 2 micron-not sure if that would make sense.
Thanks

 

[Comodave]

What engine(s) do you have? If it is a Lehman the secondary filters are about 6 to 8 microns. Most of the older engines use that as a secondary. If you have a new common rail then the secondaries would be 2 microns. I have SP225 Lehmans and use 10 micron in the Racors and the standard filters as secondaries, which are about the 8 micron. You could use 2 microns in the Racors but with the older engines 10 is probably fine. I don’t use the 30 micron because I would rather change the Racor element than the secondary.

 

[Lepke]

I have Racor 900s and run a 2 micron primary filter without problems. My secondary filters (engine mounted) are 10 micron and there for anything big that somehow gets thru the primary filter. One of the advantages to super clean fuel is less wear on pumps and injectors.

The trick to 2 micron filters is to buy clean fuel, use a good conditioner that helps the Racor separate out water and also kills organisms. My mains (Detroit) pump 70 gallons/hour while returning about 60. So I'm in effect running fuel polishing all the time. I change my Racor filter at 500 hours. By that time 35,000 gallons have passed thru the filter.

In 60 years on the water, I've never had a fuel problem. Before the EPA, I didn't have to use a conditioner.

 

[SteveK]

You may already know that an advertised micron rating can mean differences in the actual filtered micron amount. Many filters say rated 10 micron, do indeed filter 10 at least 50% of the time. Here is one interesting link.
https://www.soundingsonline.com/news/diesel-fuel-filters-which-should-you-choose

 

[Iambe]

I have 2 80 hp D254 Lehman engines. Presently as you do I have 10 micron's in the primary Racor's and the double bank FP61's have Baldwin BF625 filters. According to Baldwin these are rated at Beta 2 8 micron or 50% efficiency at the 8. I couldn't find the 90 or 99% efficiency.
I'm just concerned as so many articles I read say to use 2 micron's at secondaries but so far haven't found any standard filters that meet this. Sounds like I'm OK with the configuration I have.

 

[Simi 60]

.
I'm just concerned as so many articles I read say to use 2 micron's at secondaries but so far haven't found any standard filters that meet this. Sounds like I'm OK with the configuration I have.

Me to.

Imagine my horror when finding out our twin fs1212 on engine screw on secondaries are 20 micron.
https://www.crossfilters.com/products/fs1212-fleetguard-fuel-water-sep-spin-on?variant=7248943185967

We run 10mic as primaries.

 

[Comodave]

I have 2 80 hp D254 Lehman engines. Presently as you do I have 10 micron's in the primary Racor's and the double bank FP61's have Baldwin BF625 filters. According to Baldwin these are rated at Beta 2 8 micron or 50% efficiency at the 8. I couldn't find the 90 or 99% efficiency.
I'm just concerned as so many articles I read say to use 2 micron's at secondaries but so far haven't found any standard filters that meet this. Sounds like I'm OK with the configuration I have.

With Lehmans you are fine with 10 micron primaries and the standard secondaries. The are not high pressure common rail engines that have a much tighter tolerances. A lot of people use 30 micron as the primary filter but I like 10 as I want to catch as much crap in the Racors as I can so I don’t have to change the secondaries as often.