Recomendations for a good fuel/water separator

[heron237]

With a primary filter for a 1gm10? I'd be interested if anyone has any real world recomendations. Currently I'm running with a separator and the yanmar filter only.

Thanks

Ed

[never monday]

Racor R120AP.
30mcn element

[GordMay]

From Parker Hannifin’s RACOR Division:

Ultimately, the micron rating preferred will be a function of fuel quality, operating climates and maintenance schedules.
- Thirty-micron (PM) is recommended when the Turbine Series will function as water separator and primary filter.
- The ten-micron (TM) can be used for primary or secondary/final filtration depending on the engine and/or the application.
- The two-micron element (SM) is secondary/final filtration.

Goto: RACOR - Additives
Select "Spin-On Series"

[Pblais]

Ed,

Sounds pretty standard to me. As Gord quotes above and as posted several other places a 30 micon RACOR with a seperator is a very common arrangement. There is also a temptation to think that if you used a finer primary element it will provide better filtration. You won't find any engine professional that will agree. 30 microns will trap any growth from your tank and seperate water.

This fall bringing pour new boat home we had a contaminated fuel tank. It was running a 10 micron filter. It clogged very quickly and shut down the fuel supply. A 30 would have run a lot longer and would have completed the trip.

[ronbo1]

Paul,
In your example can't an argument be made that if your primary filter was 30 micron (instead of 10) then the load of less-than 30 micron material could clog the engine's 2 micron filter first? What's easier, changing the remote racor or the hot engine's filter?

[markpj23]

Kind of an invalid equation isn't it? The assumption is that a greater number of particles will be less than 30 microns than those that are equal to or greater than 30 microns. You also project that assumption and conclude that a 10 micron primary filter will keep a downstream 2 micron filter cleaner longer. So you effectively assume that perhaps most particles will be 10 microns or greater.

IF that assumption holds true, then yes you are correct that a 10 micron primary will keep your 2 micron secondary cleaner longer. And you will also have to change 10 micron filters more often. If the particles are mostly 30 microns or greater, you will change both the 10 and 30 mc filters at the same interval - but at greater cost for the 10mc units. True the primary filter may be located in a tougher spot to reach.

My practical experience with this has been exactly like Paul's. Bad fuel, changed 30 micron filters a lot. The secondary 2 mc filter never clogged on me during a 500 mile motor voyage.

Maybe that says something about the size of the stuff that grows in our tanks?

[Pblais]

can't an argument be made that if your primary filter was 30 micron (instead of 10) then the load of less-than 30 micron material could clog the engine's 2 micron filter first?

The argument is often made but the reality is what is less than 30 isn't usually the crap you get in normal circumstances. 30 is smaller than most thing that live in a tank and the filter will hold more garbage at 30 than at 10. Water separates the same with either unless it clogs quicker. If you actually had a problem 30 will last longer than 10. Just what do you think is smaller than 30 microns? Numerically 30 is bigger than 20 is bigger than 10 is bigger than 2 but what in the tank is at that size?

I never change filters unless I change both. Seems silly not to. I also don't wait to change them until they clog up except this one time. I suppose you could use a 2 micron as the primary. My last boat came that way when I got it. I never had a problem with it then when I changed the filters I went back to 30 microns and still never had a problem.

Most of the time you don't need the filter but then when you do you really do. I've never changed a dirty secondary filter. I still change them though.

[never monday]

I need to correct a misconception.

The engine mounted secondary filters on mechanicly injected diesel auxiliaries are NOT 2mcn. Most are 5-7mcn. Any particles less then 5mcn will pass thru the pump and injectors and burn.
Many of the newer electronicly controled diesels DO use a 2mcn secondary filter. This is to protect a pump that develops 22,000psi and fragile electronic injectors.

[ronbo1]

Pat,
Reference: misconception.
If like you say, most mechanically injected engine filters are indeed 5-7 mic then it makes no sense at all to use a 2 micron primary filter upstream.

[Alan Wheeler]

Correct, but then I only know of 10u and then they drop to 2u. I maybe wrong, but I don't know of a 5u. Correct me if I am wrong.
10u is OK for a secondary, but as Pat pointed out, an injector will pass below 5-7, so you will still get the occasional particle that could clog.
My ideal setup would be firstly att eh tanks. The tank would have a "sump" area that has a drain off valve for water to "fall" to and be able to be run off. Then two Racor's (best in my opinion) 30u primary with seperator in parrellel with a valve to switch over one to the other in an emergency. Then I would have a secondary 10u Racor(single and Seperator not required). Then the engine mounted in a 2u. (or 5-6 if available) These small filters are cheap and easily replaced and are a final safeguard ONLY. Because they are small, they can block quickly if you get a bug issue.
The two Racors are the main work horses and will stop 99% of all problems, have a large surface area so they will take a lot to block off and the primary would remove any water. Probably way overkill for most small engine installs, but recommended in any Engine power only installations, especially if you are big enough to venture out on your own.
But that is expensive and as I said, my "ideal". I can't afford that, so I have a Racor with seperator (10u) and the two secondaries on the engine. Not sure if they are 10's or 2's. Must check that.

[GordMay]

Notwithstanding the truth of all previous discussion – I’ve never (in over a thousand hours) had to change my standard Yanmar OEM filter (?2 – 5 u?).
Changed every 100 hours (by schedule, not need), I’ve never encountered any noticeable filter contamination.
I attribute my excellent experience to the quality of pre-filtred (dockside) fuel that goes into my tanks.

[Pblais]

I have two racors. If one is clogged I shut off the tank lead to it and open the one to the other. It's all done with manual open close valves. From the supply add a T then two lines with a shut off on each. You can get the racors with a bypass that allows it to flow through inlet over the top and out the outlet. You then just plumb the two racors and from the first send the output into the by pass inlet of the second that way you have a single supply and a single line to the engine. You bleed both of them so it's simple to switch one out and the other in. So long as one is close there is no need for a check valve.

You'll know the filter is full when the rpms start going down then a little lower then up and down a little lower yet. Mine took about 15 minutes to shut off. A vacuum gage isn't a bad thing to have in a place easy to see. You'll get even more warning then.

I had serious bugs in the new boat we bought this fall. At the time I didn't fully understand all the fuel plumbing system setup for this and of course could not tell the fuel tank was loaded with it's own neighborhood association. But when the racore clogged up enough to shut down fuel we did open the filter up to see what was inside. A 30 micron will stop all the stuff that grows. You won't really notice anything smaller so that isn't a bad setup. We found nothing in the secondary what so ever. Most of the stuff that grows gets big before it causes a problem and breaks up and cuts loose. It's like small cookie crumbs in size. That's huge even for a 30 micron filter. I'm not sure what the stuff thats smaller would really be between 30u and say 7u. Diesel isn't the purest substance in the world but the engines tolerate a whole lot of crap.

[ronbo1]

Misconception:

No wonder the engine fuel filters on Westerbeke's rarely clog, they're 25 micron according to my email inquiry. Westerbeke recommends the primary be 10 mics. Therefore, 2 micron as the primary seems unnecessarily fine filtration, can clog quickly stopping the engine. It appears these engines can tolerate higher particles.

Thanks Pat McCartin for your misconception.

Ron

[Alan Wheeler]

they're 25 micron

Hey you could save a heap of money and run the engine on Bunker fuel. ;-) :-)

[GordMay]

Originally Posted by ronbo1

Misconception:

No wonder the engine fuel filters on Westerbeke's rarely clog, they're 25 micron according to my email inquiry. Westerbeke recommends the primary be 10 mics. Therefore, 2 micron as the primary seems unnecessarily fine filtration, can clog quickly stopping the engine. It appears these engines can tolerate higher particles.

Thanks Pat McCartin for your misconception.

Ron

By which, I believe Ron is thanking Pat for pointing out the common misconception - not lamenting a percieved misinformation.