Water and Racor Question

[diver dave]

Racor's demo video shows their Aquabloc filter media that will "run-off" applied water. This is not accomplished with tiny pore sizes. If you pay attention to the video, they will claim that modern low sulphur diesel is now formulated with surfactants that improve the lubricity of the fuel. This has the unwanted property of surrounding water molecules, and tending to fool the media that depends on surface tension separation. They now depend on very high amounts of surface area to reduce the applied differential pressure across the media. So, it is VERY LIKELY that water, with sufficient differential pressure will cross that media. In fact, a water logged "hydrophobic" media will pass water very easily.
I have not done this exact test, but I'll suppose that if you present a virgin Racor with nothing but water, using typical fuel pumping pressures, that water will pass quite easily.

http://https://www.membrane-solutions.com/News_1336.htm

http://www.racornews.com/single-post/2014/09/11/Racors-Aquabloc-Filtration-Media-Its-Complicated

 

[janice142]

True, but wish Racor spin on filters were $10. Retail just under $80 here. I import them from USA, much cheaper, even with freight.

On Seaweed I initially had a spin on Racor, at $22 per filter that was expensive. I bit the bullet and bought a "real" Racor with the drop in filters. Doing the math it took six filter changes to break even. Every filter after six and I win. I am glad I made the change.

Because in times of stress I do not always function at 100% I labeled the top of my new Racor:

I do still have my old Racor with the spin on filter bolted to the bulkhead in the bilge.

 

[Arch]

Lepke, I don't know how this much water got into my tanks either
I certainly agree with others that a funnel filter or visible check before filling makes sense.

After four years aboard and going through over 5,000 gallons I will admit that I started taking clean fuel for granted.

The current situation is; ran for two days and thought I was through the problem. So filled tanks at a known good fuel dock that pumps thousands of gallons a week. Took off on a very rough crossing and had no problems. Then sat in a marina for a week before starting North.

Yesterday after leaving the marina yesterday the engine stopped after 20 minutes. I ran the rest of the day and well into the night at just above idle. The reduced fuel flow allowed me to almost keep up. I drained the filters every 15 minutes and only had the engine stop a few times.

I am running on one tank and hope to either filter the remaining fuel or eventually run out. This is the part of cruising you don't read about in the magazines ?

The good news is the weather is improving and I really am working on the boat in one of the most beautiful cruising areas on the planet!

Arch

 

[O C Diver]

Are you sure the water is coming in with the fuel as opposed to the tank vent, fill cap oring, or a leak?

Ted

 

[Portage_Bay]

Here's a very good article on fuel filtration. The information is particularly relevant to common rail engines but I think the information will be useful to anyone running in areas where dirty or water contaminated fuel is a common problem.

Warning, the author is not a fan of Racor.

Marine Fuel Filtration "The Seaboard Way"

 

[sdowney717]

Racor's demo video shows their Aquabloc filter media that will "run-off" applied water. This is not accomplished with tiny pore sizes. If you pay attention to the video, they will claim that modern low sulphur diesel is now formulated with surfactants that improve the lubricity of the fuel. This has the unwanted property of surrounding water molecules, and tending to fool the media that depends on surface tension separation. They now depend on very high amounts of surface area to reduce the applied differential pressure across the media. So, it is VERY LIKELY that water, with sufficient differential pressure will cross that media. In fact, a water logged "hydrophobic" media will pass water very easily.
I have not done this exact test, but I'll suppose that if you present a virgin Racor with nothing but water, using typical fuel pumping pressures, that water will pass quite easily.

http://https://www.membrane-solutions.com/News_1336.htm

Racor News

Watching the Racor video
Surfactants added to diesel to improve lubricity due to dropping sulphur from 500 to 10 ppm, are mixing so well with the water so that it has become hard to separate the water from the fuel.
So does the filter then must be shedding water mixed with some surfactants from the diesel thus the diesel is losing some lubricity?
It seems the water suspended in the fuel is causing rust, so I wonder if the metal fuel system components could be made from SS, or metals which do not corrode so easily.

The video makes me think diesel as a fuel is becoming more of a pain than it ever was before due to EPA regulations.

I have also read European cities are banning or will ban diesel engines because even with all the improvements they still pollute the air too much. They now prefer gasoline engines over diesel due to air pollution.

https://www.theguardian.com/environ...-cities-to-ban-diesel-cars-from-their-centres

This concern is increasing, so I expect more bans. China's air quality is also disastrous.

https://www.theguardian.com/world/2...s-for-second-day-running-as-pollution-strikes
Tons more people drive diesel cars in Europe due to it being you go further per gallon and the Europeans price their fuel out of sight so high, can not imagine paying those prices.

Paris smog looks real bad

 

[diver dave]

As an engineer, whenever I hear "it's complicated" from a design group, I translate that to "we don't have a great solution to the problem".
So, with newer diesel formulations, removing water is problematic. And, even if you do remove all of it, your left with hostile fuel for your closely machined injection system.
Similar to the issue of the SR71 engine fuel in the 50's. They had to make it so it would work in near space conditions, but then it lost its lubricity. I believe they ended up adding some polyethylene to the fuel for that fix.

 

[Larry M]

We went to the fuel dock/gas station in Great Harbour (Bahamas) this morning for dinghy gas and it was closed. When we filled up a little while ago I asked why. They had a delivery this morning from the fuel ship (all gas/diesel is delivered in bulk). After a deliver, they always close for a minimum of 2 hours to let the water settle out.

 

[O C Diver]

We went to the fuel dock/gas station in Great Harbour (Bahamas) this morning for dinghy gas and it was closed. When we filled up a little while ago I asked why. They had a delivery this morning from the fuel ship (all gas/diesel is delivered in bulk). After a deliver, they always close for a minimum of 2 hours to let the water settle out.

I never buy diesel for my pickup where a tank truck is dropping fuel. Dropping fuel often stirs up some of the crud in the bottom of the tank.

Ted

 

[DavidM]

After viewing that Racor video, I will never again complain about the cost of a Racor filter. I also am in love, lust, whatever.

David

Racor's demo video shows their Aquabloc filter media that will "run-off" applied water. This is not accomplished with tiny pore sizes. If you pay attention to the video, they will claim that modern low sulphur diesel is now formulated with surfactants that improve the lubricity of the fuel. This has the unwanted property of surrounding water molecules, and tending to fool the media that depends on surface tension separation. They now depend on very high amounts of surface area to reduce the applied differential pressure across the media. So, it is VERY LIKELY that water, with sufficient differential pressure will cross that media. In fact, a water logged "hydrophobic" media will pass water very easily.
I have not done this exact test, but I'll suppose that if you present a virgin Racor with nothing but water, using typical fuel pumping pressures, that water will pass quite easily.

http://https://www.membrane-solutions.com/News_1336.htm

Racor News

 

[O C Diver]

After viewing that Racor video, I will never again complain about the cost of a Racor filter. I also am in love, lust, whatever.

David

She held my attention!

Ted

 

[Capt.Bill11]

Racor water separation based on gravity, water heavier than diesel and settle to the bottom of the glass jar where you put it away. and the filter element is a network which catch in particulate larger than its rating for example. 10my

I don't believe that to be totally true.


The water separation is based on more than just gravity and the elements will not stop 100% of the particles larger than their ratings the way I understand it.

 

[Bacchus]

I don't believe that to be totally true.


The water separation is based on more than just gravity and the elements will not stop 100% of the particles larger than their ratings the way I understand it.

My understanding...
Racors spin incoming flow which is downward...water droplets coalesce and remain at the bottom.
The surface tension of water makes it harder to break apart into small droplets once they coalesce into a larger mass.
Gravity - and density of water - keep it below the diesel fuel to allow draining off at bottom.

 

[Capt.Bill11]

My understanding...
Racors spin incoming flow which is downward...water droplets coalesce and remain at the bottom.
The surface tension of water makes it harder to break apart into small droplets once they coalesce into a larger mass.
Gravity - and density of water - keep it below the diesel fuel to allow draining off at bottom.

If you check with Racor I think you'll find that unless the fuel flow rate is very high, most of the water trapping action takes place at the element.

Most engines don't draw enough fuel through the filter to create much spinning action. Especially if you use larger size filter bodies to get more element surface area.

 

[diver dave]

If you google "water molecule size", the following appears. "2.75 Anstroms", and "it is one of the smallest of all molecules".
OK, so any media that we have been buying and talking about cannot filter out a single molecule of water in diesel. So; how do these work? Well, in the chemical field of separation, you have to exploit the differences between what we want to strip out (water and junk) and what we want to keep (fuel). Water is a polar molecule, fuel is not. Meaning, water wants to attract to other water molecules (let's call that coalescing). Water is also more dense than fuel. So, we have already two possible methods of separation. Centrifugal methods will spin the solution and the mix will separate. Or, “let” the water find other like-minded molecules to lightly bond with. Surface tension, capillary attraction, etc are examples. Note the “lightly” part of the bonding. If we can let the water bond and get to be a larger body of water, then it won’t get through our relatively huge holey filter media. This is why a drop, or a dribble of water won’t just shoot though your Racor filter media. However, if you push hard enough, that body of water will break up and now its smaller than the holes, and it shoots right through, along with your fuel. BAD. That’s why flow rate is important. That’s why media surface area is important. DO NOT ALLOW the water to break apart.
But, the EPA has forced us to low Sulphur fuel. They didn’t force the fuel suppliers to use surfactants, but they had to do something to reduce injector wear. It’s a cheap, easy way to get back the lubricity that Sulphur fuel had provided.

Surfactants: chemical to inhibit coalescing. It’s in soap to allow water to get in small places and wash your laundry. Actually, it IS soap, just add perfume. Hmmm, now we have a large, fuel/water separation problem. We have added a chemical that makes water appear more like fuel. It is now much less polar. It doesn’t want to attract other, like-minded water molecules. It won’t coalesce. I can’t be blocked by a filter with large holes. It even wants to stay in suspension. HELP.
OK, so it’s even more important to keep fuel dry than ever before. It’s harder to get the water out, since 2006.

If faced with large quantities of highly suspended water molecules, you can still rely on water weight. Spin baby spin. Mechanically, run the mix in circles until the mix separates. Drain off the water. Sounds pretty manual, but there are machines made to do this. Many more boats will have these in the future.
Now what about those surfactants that we need for injector pump life that we just removed? GOOD question. I don’t know. Depends no doubt on how many surfactant surrounded water molecules you have separated and how many are left, and how many you need. But, this much is clear. The more water you are removing from low Sulphur fuel, the less injector protection you are getting. Can you add more surfactants? Probably.

 

[FF]

For any filtering operation it is far better to suck the fuel thru the filter rather than push it thru .

All pumps will mix the water with the fuel as it passes thru the pump.

Since you hope to remove the water, better mixing doesn't help..

For gravity to work, , overnight would be a minimum .

 

[Knot Salted]

Water blocking filters often use 'cornstarch' as the blocking activator. It stays untouched by fuel, but swells with water contact, plugging the filter. They will also shut down if you use jet fuel type moisture control - which I do, and therefore I use only particulate filters.

---always looking at the bowls for excess though.

 

[psneeld]

If you check with Racor I think you'll find that unless the fuel flow rate is very high, most of the water trapping action takes place at the element.

Most engines don't draw enough fuel through the filter to create much spinning action. Especially if you use larger size filter bodies to get more element surface area.

agree as that is what the literature and street says....

 

[Rogerh]

Could your problem be a bad fuel cooler contaminating the fuel with coolant or water?

 

[psneeld]

If you check with Racor I think you'll find that unless the fuel flow rate is very high, most of the water trapping action takes place at the element.

Most engines don't draw enough fuel through the filter to create much spinning action. Especially if you use larger size filter bodies to get more element surface area.

agree as that is what the literature and street says....

 

[FF]

IF you could find one ,to uses a pre filter ,, older water filtering was done with a custom glass jar containing a "sock".

The sock material was very fine mesh and did an excellent job for 1960 era diesels.

With a gravity feed it was only seconds to turn off the fuel, empty the jar , and restore the fuel feed.

 

[Ski in NC]

You don't need the spinning action to separate water to the bowl. The fuel enters near the bottom of the bowl and simple gravity is sufficient to keep it there.

Emulsified water is a different thing. Treated elements may coalesce this water, or may not, depending on highly variable chemistry.

In my experience, fuel injection equipment generally is not harmed by small amounts of emulsified water. As in if fuel is visibly clear, should be ok. I have seen where an emulsifying agent had been added and that fuel was cloudy, we got rid of it.

I have seen tank hardware damaged from moisture, but this was generally from condensation above the fuel level. But injection hardware was still ok.

I have many times encountered clogged filters that visually looked ok. But clogged they were. I suspect they had the aqua-bloc or whatever treatment and had seen too much emulsified water. Changed elements and all again was well.

Also important to know the difference between fuel lubed and oil lubed injection pumps. Many pumps the spinning parts are in lube oil and thus only the pumping elements themselves see fuel. Much more tolerant of various fuel quality problems.

It may sound pedestrian, but if I see bright clear fuel in the bowl, I don't worry.

If free water in bottom of the bowl, drain it and monitor closely as there could be a bunch in the tank.

 

[DavidM]

Since this thread has continued for some time, maybe you guys have the patience to read about how I got significant water in my fuel and how I got (most of) it out.

After laying up in the winter last year, I launched the boat and took her 20 miles downstream in the Connecticut River to our mooring in Essex. An hour into the trip we hit a straight stretch so I goosed it up to wot to see what she would do. After less than a minute the engine (a Yanmar 370 hp) lost power and I immediately throttled back to idle. It didn't die, but came close.

My buddy took the helm and I opened the engine hatch and immediately noticed that the Racor was full of water. I drained it 7-8 times and got 3-4 quarts out. Throttled up to slow cruise and all was fine.

I kept an eye on the Racor and as we approached Essex (where we could get some help if necessary) I opened the throttle to see what would happen, and again lost power, but quickly recovered. I dumped about a quart or so this time. Now I know that I have a significant water problem, if I didn't know it before.

So we throttled up 3-4 more times keeping the power at the hump point so that the bow would stay high and raise the water level in the back of the tank where the pickup is. I dumped another pint or two of water until it stabilized and I could open the throttle to wot with no problems.

I described the incident on boatdiesel and Ski advised dumping the on engine filter, which I did (and got no water) and change both filters which I didn't. The vacuum gauge on the Racor has stayed good throughout this whole process.

I have since greased and changed the fill cap o-rings and put clamshell covers over the tank vents- the plastic vent fitting has crumbled to pieces but it will take a gorilla kid to reach in to replace them so I covered up the problem .

I will go through the same process this year when I launch, but I am pretty sure I fixed the problem. No fuel cooler on this engine.

David

 

[diver dave]

I had a very similar story many years ago. Was crossing to the islands in heavy seas. Loaded up the seperator numerous times, requiring manual emptying. Root cause was the overboard vent, getting in the waves. It didn't have the required high hose routing and the applied clamshell cover was not sealed to the hull.

One more point on water in diesel. There is such a thing as relative humidity in fuel, just like in the air. It is possible to take on warm fuel, with fully suspended water, and then, as it cools in the vessel tank, the fuel will release free water to the bottom.

Since removal of suspended water in low sulphur fuel is so problematic, there are recommendations to use water absorbant "snakes" placed in the tank. Although, that too is only acting on the already free water at the bottom.

 

[Arch]

This discussion has been very helpful.

I have had two incidents of water in fuel since leaving Miami. 1st one was after a spirited Gulf Steam crossing and then sitting at a marina in Nassau for five days waiting on weather. Plenty of time for water to settle. Since I had taken on fuel in Miami, I assumed "bad fuel". After struggling for a couple of days and changing filters several times things cleared up.

I fueled again in Clarencetown and headed on. Had a full day of bashing into large waves. No fuel related issues. Spent the night in an anchorage on Crooked Island, decided to turn around as Weather was not improving. Still no issue getting back to Clarencetown. Sat for 6 nights again waiting for weather.

Headed North and within 20 minutes water in fuel. Struggled for two days before finally cutting the fuel feed line at its lowest point and draining several gallons of water before getting to clean fuel. Repaired the cut line and ran fine for 5 hours into Georgetown.

Based on your comments, I'm now betting on vent lines that comes into play in high / rough seas. I will spend some time tomorrow seeing what I can see.

Thanks again, it is good to not be out here alone,
Arch

 

[Ski in NC]

I went against convention and do not have my tank vents on hull side. And fuel fill caps are right on top of tanks with no deck fills, have to open a hatch.

Amazingly, never had any water in the tanks.

Hull side vents and deck fills are evil.

 

[diver dave]

Hull side vents and deck fills are evil.

and popular.