Fuel Filtration Systems

[gts1544]

Gentlemen,
As the OP, I want to thank everyone for their comments and input. I have learned a great deal, which is why I posed the question in the first place. Some of the information is relevant to our operation and some to others. In the BVI's, we have a relatively stable temperature environment, so I suspect that condensation is not as big an issue as fuel quality. We do have a Baja filter, but the dock boys always seem to be in such a hurry that I have seldom used it. Since it has been well over 5 years since our tank was cleaned, I think that there is the place to start. Thanks again to all who responded. Please feel free to continue this thread as I am sure that many of us are benefitting! gts1544 - George

[noelex 77]

Originally Posted by Nicholson58

You should be aware that the Racor filters we all use have an internal bypass relief valve so that once the filter becomes plugged dirty oil bypasses the element.

550 dollars to rebuild my main pump would have easily paid for the new filters for the entire boat.

Do you mean Raycor fuel filters? (Diesel is called diesel oil in some languages which can be a bit confusing)

The larger Raycor fuel filters like the 500, 900 etc have a plastic tab that can be punched out in an emergency to bypass a blocked filter. This cannot happen without a deliberate action. They also have a water check valve that will cut the flow with water in the bowl. As far as I aware there is no internal bypass relief valve.

If I have this wrong, or if it different on the smaller spin on filters it is important for owners to know. Could you elaborate?

[DeepFrz]

Since it has been well over 5 years since our tank was cleaned, I think that there is the place to start.

Yes. I second this. Also be meticulous about the seals on your fill caps. These small o-rings are easily damaged and can let in a lot of water.

[noelex 77]

Originally Posted by DeepFrz

Yes. I second this. Also be meticulous about the seals on your fill caps. These small o-rings are easily damaged and can let in a lot of water.

Why do boat builders often fit diesel inlets flush on the deck close to the toe rail?

As a double protection I cover mine with waterproof tape. A nuisance to remove, but with a 1000 litre capacity we only fill rarely.

I am currently thinking about the specs for a new boat. One of the many requirements is a diesel tank fill that it not subject to any likelihood of water ingress.

[cabo_sailor]

Bravo gentlemen,

A well argued thread. When I bought my boat I neglected to have my fuel/tank cleaned. I paid for that mistake at about 3 am in moderate chop.

I now have dual Racors that seem to have more valves than a nuke reactor. I just had my tank cleaned and fuel polished but as a result of this thread I am now convinced to add the vacuum gage as well.

Again thanks to all for an excellent discussion.

Rich


Sent from my iPhone using Quantum Entagelment

[captain58sailin]

Hopefully you have the two hard piped together and 3 way valves between them, makes for a simple switch over on the fly. I am a believer in the vacuum gauge, gives me an early heads up on pending failure and I can address it prior to engine failure.

[Kenomac]

This subject comes up on the forum over and over again. Install something like this and the problem goes away forever. $1500-$2000 installed and will pay for itself the first time you get a bad tank of fuel. Dual Racors that feed the engine and generator with a switch lever in case one filter becomes clogged plus the fuel polishing system filter on the right. Fuel can be polished anytime with or without the engine running, it's completely independent. Polishes 150 gallons per hour using a Reverso polishing module/pump.

[captain58sailin]

Very nice indeed!

[DeepFrz]

Originally Posted by Kenomac

This subject comes up on the forum over and over again. Install something like this and the problem goes away forever. $1500-$2000 installed and will pay for itself the first time you get a bad tank of fuel. Dual Racors that feed the engine and generator with a switch lever in case one filter becomes clogged plus the fuel polishing system filter on the right. Fuel can be polished anytime with or without the engine running, it's completely independent. Polishes 150 gallons per hour using a Reverso polishing module/pump.

That would have been nice to have before we had a clogged fuel line off the western tip of Cuba in the Yucatan Channel. The only time as an adult that I have been sea sick.

[Cheechako]

You need to solve your fuel problem. Then it wont matter which filters you use. If you go to a 10 micron it will just clog up sooner! Letting less fuel through and risking a complete engine stoppage.

[thinwater]

"A few grams"

If the fuel was very near saturation already, and the boater did not use the boat for 6 months (common in storage) a few grams can cause a haze. If the boater only uses the engine in and out of the slip, in fact, it is common for fuel to last for several years. This is not going to happen to a regular cruiser, but it certainly does happen, and that is what I had been asked to model; long tern storage.

Corrosion and biogrowth. IS it required to have free water? NO it is not. I did a series of tests on both subjects and the bottom line is that free water is NOT required. It certainly speeds things along, and severe growth requires free water, but no free water does not equal zero growth. The same is true with corrosion. Every ppm accelerates corrosion; in fact, all of the corrosion testing I did was with zero free water. But it is slower, no question. In both cases, contamination with ethanol seems to be problem (very low levels), and that should not be a surprise, since equipment is shared with e-10.

The point is that a vent filter is a significant help for boaters that leave fuel in a tank for 6 months or more. It costs very little for the DIY (easy to make) and is cheap insurance. For the year-round cruiser there is no benefit at all, regardless what the manufacturers say. It is that simple.

Gasoline is a very different case, with much higher breathing rates; the vent filter will pay for itself in saved evaporation alone (remember, they last ~ 10 years in this application--they self regenerate), before we even talk corrosion, gum formation, and easier starting, so it's a no brainer. However, DIY is a little more difficult since PVC pipe won't work.

I fabricated this one from a Vetus housing (internal screens to support the resin) 3 1/2 years ago and it is still performing like day 1. I used a Vetus housing because I was experimenting with resins and it was easy to service.

[Dockhead]

Originally Posted by noelex 77

Why do boat builders often fit diesel inlets flush on the deck close to the toe rail?

As a double protection I cover mine with waterproof tape. A nuisance to remove, but with a 1000 litre capacity we only fill rarely.

I am currently thinking about the specs for a new boat. One of the many requirements is a diesel tank fill that it not subject to any likelihood of water ingress.

Moodys have the fuel fill led up through the side of the doghouse, with the filler inside a cavity in the doghouse side, closed with a door, about a meter above deck level. I believe this is a common arrangement on motor yachts. The fuel tank vent is inside the center cockpit with a raised loop. I recommend an arrangement like this if you're having a new boat built. Fuel fills flush with the deck are madness. One crappy little o-ring between green seawater and your fuel -- madness.

[DeepFrz]

Originally Posted by Dockhead

Moodys have the fuel fill led up through the side of the doghouse, with the filler inside a cavity in the doghouse side, closed with a door, about a meter above deck level. I believe this is a common arrangement on motor yachts. The fuel tank vent is inside the center cockpit with a raised loop. I recommend an arrangement like this if you're having a new boat built. Fuel fills flush with the deck are madness. One crappy little o-ring between green seawater and your fuel -- madness.

Off topic but I would recommend the same for your water fill.

[zboss]

Originally Posted by Kenomac

This subject comes up on the forum over and over again. Install something like this and the problem goes away forever. $1500-$2000 installed and will pay for itself the first time you get a bad tank of fuel. Dual Racors that feed the engine and generator with a switch lever in case one filter becomes clogged plus the fuel polishing system filter on the right. Fuel can be polished anytime with or without the engine running, it's completely independent. Polishes 150 gallons per hour using a Reverso polishing module/pump.

I wish they made one that was 1/4 the price at 1/4 the hourly capacity! We only have 50 gallons of tankage.

[noelex 77]

Originally Posted by Dockhead

Moodys have the fuel fill led up through the side of the doghouse, with the filler inside a cavity in the doghouse side, closed with a door, about a meter above deck level.

Thanks. I will take a look at it. So many decisions, each with some compromise involved.

I was going to request a fuel fill in the cockpit combing, but as it happens the boat is normally built with standpipes for fuel and water topped with an overlapping and very waterproof looking cap.

A simple system, not quite foolproof, but much better than the normal flush inlets.