Is 10 micron enough?

markpierce wrote:*Makes one wonder why most of the Racor filters listed in the West Marine catalog are 2 micros.

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For the same reason Racor sells a "fuel polisher" that flows 4 gallons per*hour ... because people will buy them.

RickB wrote:markpierce wrote:*Makes one wonder why most of the Racor filters listed in the West Marine catalog are 2 micros.

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For the same reason Racor sells a "fuel polisher" that flows 4 gallons per*hour ... because people will buy them.

*You are 110% correct.* If it is in demand and has a turn over they*(West Marine) will*stock and sell it.* Let me modify that, they will*built a knock off of it then raise the price of the original and sell their West branded one for what the original one sold for.* If it is good for you or not is not in their business model.* And maybe it shouldn't be.

Good response!

RickB wrote:markpierce wrote:*Makes one wonder why most of the Racor filters listed in the West Marine catalog are 2 micros.

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For the same reason Racor sells a "fuel polisher" that flows 4 gallons per*hour ... because people will buy them.

*Hmmm*- Frightening thought,*but probably true!!

ps:*4JHE Yanmar, per my service manual, should have come with a 129470-55700 fuel filter element, but I suppose someone could have spun a different*one on?




-- Edited by Edelweiss on Tuesday 10th of January 2012 09:47:06 PM

Edelweiss wrote:RickB wrote:markpierce wrote:*Makes one wonder why most of the Racor filters listed in the West Marine catalog are 2 micros.

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For the same reason Racor sells a "fuel polisher" that flows 4 gallons per*hour ... because people will buy them.

*Hmmm*- Frightening thought,*but probably true!!

ps:*4JHE Yanmar, per my service manual, should have come with a 129470-55700 fuel filter element, but I suppose someone could have spun a different*one on?



*

You are correct.

Fuel Yanmar filter 129470-55702.* That is a 2 micron filter with a product impregnated into it to lube the injection pump according to Mack Boring.

*

You are correct.

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Fuel Yanmar filter 129470-55702.* That is a 2 micron filter with a product impregnated into it to lube the injection pump according to Mack Boring.

*

*The filter guide I have shows it's 5 micron


-- Edited by Edelweiss on Wednesday 11th of January 2012 12:24:08 AM

Edelweiss wrote:You are correct.

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Fuel Yanmar filter 129470-55702.* That is a 2 micron filter with a product impregnated into it to lube the injection pump according to Mack Boring.

*

*The filter guide I have shows it's 5 micron

*

*That*may well be correct.* The issue or question*at the school was why not put a 2 micron in the primary*Racor and be done with it.* The instructor said that the primary has to be a 30 micron to allow adequate fuel flow and the final filter on the engine*will take care of the rest. I may have confused the 2 from the Racor as being what the final was or is.

He then went into the spill about the impregnated chemical that lubes the injection pump.* He said that the final filter was good for 100 hours or one year which ever comes first.* The one year is due to the rate at which the chemical leaches into the fuel overtime. At the end of one year there will not be any remaining to lube the pump.* So I guess that if the boat sits for two months the first fuel to the pump would have a more concentrated amount of lube in it than the rest of the day.

To be truthful it sounded like BS but hey I paid for the class and as in any class sponsored buy someone they do have an axe to grind.* I feel as long as what they tell you doesn't hurt your engine then you are fine. So changing the final filter every year with the factory filter didn't seem like it would, extra lube or not. I'm a believer of using OEM filters and parts anyway.

"The instructor said that the primary has to be a 30 micron to allow adequate fuel flow ..."

Flow rate requirements*can be handled by using a physically larger element.*A too-small 30 micron element is worse than a marginal sized 2 micron element.

It is entirely*possible to install a single large 2 micron filter at the tank outlet and leave the OEM engine filters as delivered.

Whether it is practical or not is up to the user.

RickB wrote:
"The instructor said that the primary has to be a 30 micron to allow adequate fuel flow ..."

Flow rate requirements*can be handled by using a physically larger element.*A too-small 30 micron element is worse than a marginal sized 2 micron element.

It is entirely*possible to install a single large 2 micron filter at the tank outlet and leave the OEM engine filters as delivered.

Whether it is practical or not is up to the user.

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*Understood.* The*small filter will never be able to*deliver the correct amount of fuel but the large one will as long as the 2 micron filter is clean.* I questioned*(to my self)*the statement being as*the Racor in question was way over rated for the flow rate of the Yanmar it was covering.* But the instructors do have to talk in generalities sometime*when they speak to a class.* Otherwise it will take half a day on just the flow rate of a specific filter.

The on engine filter can be called both a 2 and 5 micron rating dependent upon how they apply the most important criteria "beta number." A stamped 2u filter with a beta of 80 means 80% of the 2u and over particles*are trapped, 95 - 99% (pick a number) *of the 5u and over are trapped and* 99.9 of the 10u and larger trapped. Some filters are called 2u but they*have a 60% (or some such lower value)*beta number. These are pure junk but how do you know when only 2u is stamped on the filter?

The engine manufacturers will*spec out a complete beta profile for all sizes passed and when sourcing filters pass this profile on to the supplier as a "mandate." This is why OEM fuel filters are best used, even though more expensive in most cases. And too, this is why the OEM counter guys really don't know the micron size but somewhere in the organization they better know the beta number.* Especially if you have a TierII / III engine under warranty. In my years of experience with very large Cat equipment, it was uncommon to have a recall on fuel filters for improper sizing - but it can happen. Cat checks their filter suppliers on a random basis to insure quality control. There is a standard test for establishing beta numbers.

The shape of the particle can have an influence on % passing too. PhD thesis are done on this subject, for all types of filtering applications. Most beta tests are done on rounded and elongated particles to insure quality control and proper engineered design of the filter media. Picture a 2u round pebble compared to a 2u x20u pebble. Under a microscope they are indeed pebbbles or rocks. But on many 2u stamped filters they both pass. So engineered layering (more expensive) of the filter media is critical, to allow only say a 2u x 5u to pass.

But what causes more damage, a poor 2u filter or water in the fuel. Likely the latter.

*

*



-- Edited by sunchaser on Wednesday 11th of January 2012 10:17:18 AM


-- Edited by sunchaser on Wednesday 11th of January 2012 10:19:03 AM

Thanks Sunchaser,

Very informative.* I didn't think about there being a range under any set number.* But it makes sense.* Is there*any way to know the Beta number of a particular filter?

I agree, OEM is the only way to go.* Yes other companies make the filter for them and then sale a filter that will replace the OEM number but who knows what is inside of the replacement.* The case and the flange (spin on) mate up but after that what is different?* There usually is a reason for it to cost less.


-- Edited by JD on Wednesday 11th of January 2012 11:03:01 AM

JD wrote:I didn't think about there being a range under any set number.*

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The machinery OEM requirement is very precise, refer to my post of last Sunday (we really do need post numbers within threads*here) that begins with "It may be interesting to some that Racor 2 micron filters are made for the after-market user."

That shows what the OEM is looking for as far as its filter needs. The filter manufacturer has to meet that spec (among others)*within the envelope provided. That is why the machinery OEM*that rebrands a filter does not have to state the micron size, it just tells you that*"their"*particular filter number such and such*is required - or else.

sunchaser wrote:
The on engine filter can be called both a 2 and 5 micron rating dependent upon how they apply the most important criteria "beta number." A stamped 2u filter with a beta of 80 means 80% of the 2u and over particles*are trapped, 95 - 99% (pick a number) *of the 5u and over are trapped and* 99.9 of the 10u and larger trapped. Some filters are called 2u but they*have a 60% (or some such lower value)*beta number. These are pure junk but how do you know when only 2u is stamped on the filter?

The engine manufacturers will*spec out a complete beta profile for all sizes passed and when sourcing filters pass this profile on to the supplier as a "mandate." This is why OEM fuel filters are best used, even though more expensive in most cases. And too, this is why the OEM counter guys really don't know the micron size but somewhere in the organization they better know the beta number.* Especially if you have a TierII / III engine under warranty. In my years of experience with very large Cat equipment, it was uncommon to have a recall on fuel filters for improper sizing - but it can happen. Cat checks their filter suppliers on a random basis to insure quality control. There is a standard test for establishing beta numbers.

The shape of the particle can have an influence on % passing too. PhD thesis are done on this subject, for all types of filtering applications. Most beta tests are done on rounded and elongated particles to insure quality control and proper engineered design of the filter media. Picture a 2u round pebble compared to a 2u x20u pebble. Under a microscope they are indeed pebbbles or rocks. But on many 2u stamped filters they both pass. So engineered layering (more expensive) of the filter media is critical, to allow only say a 2u x 5u to pass.

But what causes more damage, a poor 2u filter or water in the fuel. Likely the latter.

*

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*Tom, given the beta rating dynamic, doesn't that make the case for fuel polishing?* In other words, if fuel is cycled through a 10u filter multiple times, the 20% of particles it passes greater than 10u have a higher likelihood of being trapped the second, third, etc. pass through?* Or am I missing something?* Is it not also true that a filter increases in efficiency as it does its job because particles start plugging the leaks so to speak?* I realize that there is a point where the filter is clogged, but before then, does the efficiency of filtration actually go up over time?* And why does every sentence in this post end with a question mark???

Just curious, not challenging. But in all this discussion about micron size and beta numbers, how much of a problem is really being talked about here? Most everyone I know with a cruising boat uses a Raccor filter of some sort in their system, usually as the primary (first) filter in the line. And pretty much everyone I know whom I've talked to uses 2-micron filters in them. For the secondary (on engine) filters, the boaters I know either use the OEM's branded filter or if it's an older engine like ours they use 2 micron filter(s). And I have yet to meet anyone up here who has had any sort of fuel problem--- of any kind--- other than running out of it. Granted, we have a very high fuel turnover at our local fuel docks and many of them have relatively new storage tanks. I have never seen dirt or even water in the bowls of our filters. Someone running in an area with a less-than-ideal fuel supplier may be a whole different story.

For commercial vessels (or heavy equipment in Tom's case) or yachts that rack up a lot of long-distance running hours every year I can understand where this whole filter spec thing can be important. But in boats like most of us have, given the way they are used, is all this business about micron and beta numbers, etc. actually something that matters? What's the problem with doing what I suspect many or maybe most recreational boaters do: use filters that will catch pretty much everything and leave it at that?

Delfin -- IMHO, fuel polishing will not*hurt and on bad fuel or dirty tanks it will likely be of great help. Yes the constant recycling will do some good too. Plugging filters indeed seem to play a positive role, to a point. As RIckb pointed on post 7, or was it 17, aircraft engines are on the higher end of the fuel filtration curve. What they do must work well, I have never heard of jet fuel causing a wreck, other than a lack thereof. I maintain that on smaller boats and heavy equipment, good multistage filtration obviates the need for polishing, but if you have both the dreaded instant lack of diesel clatter is far*away.*

Marin -- I can only agree with you on why the fuss on*older and*well maintained trawlers burning*low lbs/hr. The engines of the last decade or two however have a different*fuel filter need, at least according to the manufacturers. In my industral experience, it is amazing to see the stuff that an AlfaLaval centrifuge picks up*up*from presumably clean and filtered organics.

What are thoughts on the Alfa Laval and similar diesel fuel systems Rickb??????????*

sunchaser wrote:
I have never heard of jet fuel causing a wreck, other than a lack thereof.

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It has on at least one occasion. It was found that the British Airways 777 that lost power on short final into Heathrow Airport in London and bellied in on the lawn had been fueled with improperly formulated fuel in China prior to the flight.* The fuel was not as resistant to cold temperatures as it should have been.* As a result of part of the flight over Russia passing through some amazingly cold air, the fuel gelled and screwed up the function of the fuel system (I don't know the specifics of what got plugged or rendered inoperative).

In any event when power was reduced for descent into London, whatever happened happened, and when the crew tried to add power (as is often required) on short final, one engine refused to power up beyond flight idle, while the other one powered up briefly and then dropped back to flight idle.

The search for the cause was eventually focused on the fuel when no problem whatsoever could be found with any of the plane's systems.* When the fuel was tested, it was found to be seriously deficient in resistance to cold.

Nobody was injured but the plane was totalled and was salvaged for parts.

"Most everyone I know with a cruising boat uses a Raccor filter of some sort in their system, usually as the primary (first) filter in the line. And pretty much everyone I know whom I've talked to uses 2-micron filters in them"

Well I certainly do not use a 2 micron. When I bought my boat and made my maiden/delivery voyage, it was set up with dual Racors with 2 m elements. The most I could get was 8 running hours before they clogged.

So after I got to my home port, I attempted to polish with a borrowed rig and got almost nothing in the filters, but then I was sucking out of the top of the tanks (even though the hose was going to the bottom).

So I added a 30 micron Racor as a first filter, then changed the originals to 10 micron. Never another clog. Heck, I rarely even get a reading on the vacuum gages. For my experience, multistage with "course" elements is the only way to go.

And while that doesn't work for everyone, it certainly is an excellent option. I might still have dirty fuel in my tanks, but it's a non issue at this point in time.

Have dual Racors. Cummins. Just after we bought the boat I went to get 10 micron filters at the local yard that services Cummins and a large number of commercial lobster boats as well as many pleasure boats. Engine shop told me that in their experience 10 microns was overkill and that 30 microns was what "everyone" used and what the yard recommended as primary filter. No probs so far and vacuum gauge hasn't budged.

dwhatty wrote:
Engine shop told me that in their experience 10 microns was overkill and that 30 microns was what "everyone" used and what the yard recommended as primary filter. No probs so far and vacuum gauge hasn't budged.

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*That's because all the crap is going right through the 30 micron filter to your engine!***

Welcome back, David!*

We have 2 micron filter elements on everything and the vacuum gauges have never moved off zero. But the boat had new tanks when we bought it and the design and layout of the tanks is such that they all feed from the lowest point in the tank. Plus our fuel up here is very clean. The filter elements that come out, other than being darker from the fuel, look just like the new elements going in.

If one has dirty tanks, then I can certainly see how 2 micron or even 10 micron elements could be problematic. But the recommendation to us was to use 2 micron elements all around and in thirteen years so far I'm still waiting to see dirt or water in the filter bowls. So in our case, at least, and apparently in the cases of other boaters I know personally, the whole micron thing is a non-issue. Which is why I asked the question I asked earlier. How big a deal is it in reality for our kind of boating?

"If one has dirty tanks, then I can certainly see how 2 micron or even 10 micron elements could be problematic."

It all depends on how big the filter element is in relation to the volume of fuel required to pass through it.

Install a large enough filter and you'll neve have to worry about clogging because it might hold more crud than the fuel tanks. Install a too-small filter and a teaspoon of crud might block it entirely.