Fuel Polishing System Installation

[Dockhead]

Originally Posted by captain58sailin

Not to throw fuel on the fire so to speak. Despite the logic presented here about condensation on partial full tanks. I was taught on my Father's knee, that you keep fuel tanks full to prevent condensation in a tank, boat or otherwise. In my neighborhood even a small amount of water can form ice crystals which will clog filters, a bad thing when at sea in a storm. Also, when one's tanks are filled in the fall, the fuel price has never been less come spring, so I can run for an extended period of time before shelling out for the more expensive fuel. I use Power Service in my fuel as a conditioner, cannot say if it is effective, the point is to prevent a problem rather than deal with the after effects, it may be merely the placebo effect, but it makes me feel better and so far as I know, it hasn't hurt the engine performance. I also use an algaecide, and a centrifuge. I use the centrifuge as the fuel exits the tank, before it gets to the filters, so far it has worked well. I intend to post photos of my system, which is home built as soon as I get my engine out so I can take some good photos of the mount, pump, manifold etc... I should be done with my engine removal by the end of Sept. I have no interest in Power Service, I am only a customer.

I was taught the same thing on my own fathers knee. Some things I learned there were valuable nuggets of wisdom, others, like this, turned out to be old wives' tales.

[captain58sailin]

That may be true. I have never had a fuel related break down offshore, so I'll stick with what works for me.

[thinwater]

Originally Posted by Dockhead

Why do you say I assume that diesel is not hydroscopic? I'm struggling to see where we disagree.

On the contrary, I'm saying that 10 gallons of saturated, oxidized fuel is a hell of a lot better than 90 gallons of it. And when water starts to precipitate out of fuel, wouldn't we rather have the water which comes out of 10 gallons, then out of 90 gallons?

Where do we disagree?

I think where we differed is that saturated fuel can drop water when the temperature drops, since solubility is a strong function of temperature.

We know that condensation does occur on the underside of tank roofs, a fact that cannot be dismissed. Therefore, there is a mechanism. Since it isn't wave action (shore tanks) and is more a problem in coastal areas, we can deduce with some confidence that humidity is involved. We cannot dismiss that water in the fuel could also be a factor; not enough data.

You assume that the only breathing is driven by temperature change; in fact, simple convection is often the greater driver, depending on tank geometry and the temperature difference between the air and the tank. I have documented this when doing fugitive emmisions calculations from both refineries and boats (there are hydrocarbon emissions even when a tank is cooling, if the vent lines are large in comparison tot he tank, which boat vents are (a working vent would be ~ 1/8").

This is a case where observation is more accurate than calculation--much of life is like that--and the number of variables from tank-to-tank, place-to-place, and season-to-season are overwhelming. Sufice to say that it is very rare for it to be serious enough to cause visible water, but not so rare that the increase in water saturation is irrelavant; saturated fuel is more corrosive and prone to infection. It is also know that infection does not require free water; a large infection, yes, but enough biofilm to influence corrosion, no.

As for fuel polishing, it can only help. As for additives, I've seen those that can make it worse, but I'm going to leave that alone in a forum. Stay with the best known and don't look for a miracle claim from a smaller maker. That doesn't really make sense, chemisrty is well researched, and I haven't seen small brand stand-outs. Too bad.

[lawkmlaw]

awesome

[Aloha_float]

I read the response to water saturation in fuel. Diesel fuel can naturally absorb up to .01% of its weight in water. natural absorption is ~100ppm but fuel can absorb higher amounts. Cloudy diesel can be as high as 350ppm or greater. I work with contractors who have developed new methods to remove water from bio-diesel blends as well as conventional blend diesel.

If you end up with a bio-diesel in your tank, the presence of bacteria increases the likelihood of developing degraded FAME which we describe as "black honey". This stuff is very viscous and virtually insoluble so it has created havoc in fuel systems.

As far as additive chemistry goes - there is still a ton of research being done and yes there is a technology out there that far outperforms biocides and conventional additives when it comes to removing biofilms, hindering corrosion related to the presence of bacteria and Improve engine performance. The large additive companies do not have the upper hand in everything; they are commercially very rich and can beat a small player in the big game however, I would not assume that bigger is better.

We are in the additive business and have been focused on R&D for 20+ years - I am not going to share the brand for the sake of being ostracized by the moderators but suffice to say that we have gained significant ground in the marine sector and the premium diesel supply market. Do you homework on line searching for information on diesel sludge removal and reach out to the companies that focus in this area and ask them for the back up material to support their claims.

I have spoken to marine operators around the world and their fuel suppliers dismiss any answers to diesel sludge and bio fuel issues. Their primary role has become logistics and the old school technical support does not exist like it did in the past. It's a shame because there are solutions - it's just a matter of education. Don't believe that because someone is not aware, that there is no answer; it's simply ignorance.

[Kenomac]

Originally Posted by lawkmlaw

awesome

Thanks. We polish our fuel weekly, and all fuel related issues are gone. No more worries or screening fuel at the dock.

[Omatako]

I was not a frequent visitor to this board at the time of this thread so have just read the whole thread. I must say I passed over the extensive chemistry lessons (they were off-topic anyway) and also those posts that insist on re-posting the full chemistry lessons.

As a boat owner who is not anal about fuel polishing, I've always thought that a good indicator of fuel quality is the amount of "stuff" that gathers in the sight bowl of the filter unit. No "stuff", no problem. At least, that's how I've done for the last 40 years. It's daunting to now discover that I was wrong all those years and could have had a cataclysmic failure at any moment.

I've only once ever been sold bad fuel and not having a world class polishing system (read no polishing system, just tandem inline filters) I must admit it was a PIA. But once in 40 years?

Anecdote: When in the Marquesas some years ago, another visiting boat told me not to load local fuel or if I had to, use a filter jug because the fuel at the wharf was totally contaminated. So I went there armed with a Baja filter funnel but the fuel station owner forbid its use saying it would take too long and hold up the pump for other clients.

When I said that I was nervous of the fuel quality as reported by other boats, he went ballistic. He vehemently pointed out that he routinely fuelled deep sea fishing boats with 1000s of gallons of fuel and had NEVER had one captain complain of the quality of fuel. "How long would I get away with risking people's lives at sea by selling them dirty fuel? These people would skin me alive." was his closing argument. I filled my boat and had no problems with the fuel. End of anecdote.

Still, if fuel polishing is your passion then there are some seriously cool systems posted here. The bypass system on my Yanmar passes enough fuel that has just been filtered, back to the tank to (in my experience) keep it acceptably clean. I do have the ability to draw from one tank and bypass it back to another so if I do spot sediment/moisture in either of the sediment bowls, I would probably do that but have never had cause to.

Maybe my first cataclysmic failure in 40 years is just around the corner.

[DeepFrz]

[QUOTEMaybe my first cataclysmic failure in 40 years is just around the corner.][/QUOTE]
It could very well be and I hope if it is that it happens at the dock, not in a busy seaway. I can tell you from personal experience that it is not a fun situation.

[Tacky]

I would like to thank the several people that contributed so much valuable information on this thread. Having just gone through several engine loss situations (fortunately was able to handle them and was provided favorable circumstances) this is of paramount importance to me personally. The ideas for polishing rigs/techniques have been really helpful - also appreciated when people listed specific components like pumps they used.

Also I would respectfully disagree with the comment that the chemistry discussions were off topic. Root causes and the best practices that mitigate them are very important and the research and knowledge shared by several people here was very enlightening. Again thanks.

[Kenomac]

You're welcome. Please contact me anytime.

One change has been made to our fuel polishing system.

We have needed to separate the Generator onto it's own Racor filter recently, the Tee wasn't working out. When we'd run the engine sometimes the fuel would drain out of the generator feed hose then allow the engine to suck in air via the generator fuel system. Other than that, it's been working out great.

Ken

[Kenomac]

Originally Posted by Kenomac

You're welcome. Please contact me anytime.

One change has been made to our fuel polishing system.

We have needed to separate the Generator onto it's own Racor filter recently, the Tee wasn't working out. When we'd run the engine sometimes the fuel would drain out of the generator feed hose then allow the engine to suck in air via the generator fuel system. Other than that, it's been working out great.

Ken

UPDATE:

Here's a photo of the separate Racor for the generator. Both the engine and generator were adversly effected by the common fuel supply tee originally installed two years ago causing air to be sucked into each at times. The separate Racor has solved the issue.

[poiu]

I have a home built system. I learned recently that motor yachts often install polishing systems but they go for a 2 micron filter. I am on 30. I picked that because my primaries at 30 micron catch everything and the secondary at 10 micron never gets clogged. Maybe I have been lucky and there is a good reason for having 2 micron. Certainly there may be better reason for fine filtering with more modern engines as fuel system tolerances required for common rail engines are much higher and that may be reason enough. With an older engine I don't have that concern.

[Kenomac]

Fortunately in the Med, the fuel quality is quite high. Before the fuel hits our engine, it's been polished by the system, then filtered by the Racors the finally filtered by the engine prefilter. This season, somehow we got by on only 300 gallons of fuel to cover all our travel needs for 1500 miles and generator charging needs for 130 days, so I didn't need to change any filters after July and probably won't need to touch them again until the conclusion of 2017.

[Dockhead]

Originally Posted by poiu

. . . Certainly there may be better reason for fine filtering with more modern engines as fuel system tolerances required for common rail engines are much higher and that may be reason enough. With an older engine I don't have that concern.

Actually what I've heard is the opposite -- that common rail engines are much more tolerant of bad fuel. I can't say whether that's true or not, but it comes from a friend of mine who owns a huge Bosch fuel injection repair center. He says that mechanical fuel injection pumps have extraordinarily close mechanical tolerances and can be destroyed by very tiny amounts of grit or water. The electromechnical injectors-cum-pumps on common rail engines are much less sensitive.

True or not, I can't say, but that's what I was told. In any case, I am awfully careful with my "old fashioned" engine, what concerns fuel quality. I will definitely have a polishing system on my next boat. On my present boat, I keep a 2 micron filter in one side of my dual Racor, and a 10 micron fliter in the other. I use the 2 micron filter and I watch the vacuum gauge. If it were ever to start to clog up, I would switch to the 10 micron side, and I keep a case of 10 micron filters handy in case of a fuel problem.

Meanwhile, in normal use, the main engine is polishing the fuel by circulating it through the 2 micron Racor. Not as effectively as Ken's system of course since fuel is not drawn from the very bottom of the tank.

[poiu]

Originally Posted by Dockhead

Actually what I've heard is the opposite -- that common rail engines are much more tolerant of bad fuel. I can't say whether that's true or not, but it comes from a friend of mine who owns a huge Bosch fuel injection repair center. He says that mechanical fuel injection pumps have extraordinarily close mechanical tolerances and can be destroyed by very tiny amounts of grit or water. The electromechnical injectors-cum-pumps on common rail engines are much less sensitive.

True or not, I can't say, but that's what I was told....

I'm not writing as an expert in this area either, but I don't think that is correct. I have read and heard contrary information multiple times. I don't know if this article linked below from Yachting Monthly is better informed than your guy. Here he says that because of greater tolerances in the parts direct injection engines have to protect from particles of 6-7 microns, whereas common rail have to protect down to below 2-3 microns. Reading that it looks like my 10 mu filter isn't really good enough even for an old engine.

Reasons to be paranoid about Diesel