Ultra low sulphur diesel and water traps

Eagle
Don’t you want the Water Watch as first item in the fuel flow, then a pre filter, then the OE filter, then the engine. I agree a 2 micron is good but if after the OE filter it can restrict flow if blocking and the restriction sensor if in the EO filer won’t then detect restriction. That isn’t good.

If the WW is after the OE filter then the OE filter already has water in it/ through it before The WW does any warning. That is not the way I would want it to happen.

To my way of thinking the name of the game is to be alerted to/ stop water ingress to the injection system, any additional filtration is just a bonus but not a necessity as the OEM units are satisfactory for the task

Ally
Often trucks, not all, use a pump and filter which draws from tank and returns it to the tank to clean the fuel in the tank so the OE fuel is relieved of as much water and fuel contaminants as is possible. The cleaner the fuel the better the CRD high pressure pump and injectors will last. So is the OE filter suitable for general purposes or is better filtering of emulsified water and fine contaminants a good idea. You decide.

RMD, no I am happy with what I have as the stanadyne fuel manager has a water alarm when the bowl has trapped a certain amount of water. If anything gets through it undetected the fuel manger which is very sensitive hopefully picks it up.

As for the 30 microns I am happy with that as well, being a primary filter I only want to catch the rocks. I only change the factory filter at 30000K. The least I disturb the filter the less likely to introduce contamination into the high pressure pump and injectors.

It all works for me.

"Often trucks, not all, use a pump and filter which draws from tank and returns it to the tank to clean the fuel in the tank so the OE fuel is relieved of as much water and fuel contaminants as is possible. The cleaner the fuel the better the CRD high pressure pump and injectors will last"

This is not correct. All CRD systems circulate fuel between the high pressure pump and the fuel tank, at a high (litres per hr) rate - simply because a very substantial amount of heat is generated by the high pressure pump, when it compresses the fuel to the high pressure needed for the common rail.

This heat needs to be dissipated, or the fuel would start to boil in the pump and common rail, leading to major problems.

So the heat is dissipated by circulating the fuel at a high litre per hour rate, between the pump and the tank.
On the Isuzu D-Max for example, the fuel circulation rate between pump and tank is well over 80 litres an hour.

In fact, the heat generated by the high pressure pressurising of the common rail often can't be removed even by constant fuel circulation - and to this end, you will also find fuel coolers (an aluminium block with lots of fins) mounted in the return fuel line of most CRD diesels today.

Cheers, Ron.

Ron N
Why do you say it is wrong that trucks have a circulatory system to "polish" fuel. They DO.
That system is separate from the CRD system which does circulate fuel for cooling reasons.
Early Dmax has a fuel cooler, later ones don't as far as I have noticed. Not a finned one as mentioned.
The fuel circulation rate of 80litres/hr is well above what IUA mentinioned when asked that question.
If you listen to a 2011 Dmax you can hear the pump slow as it develops pressure against the regulator valve. Mine is around 40L/Hr at a pressure of 6psi.
My cooler isn't an aluminium block with fins but similar to an auto trans cooler. So quite different.
BT50 don't have a fuel cooler but have a tin tank on early models.

Donaldson filter compny sell kits for auxilliary filtering and match the filter size, ie, flow rate well above ie, 3 times more than the actual flow rate of circulation. The filters are, mine is, 114L/hr. After conferring with them I used their product, they seem to know what they are on about.

The heat you mention may not be so severe as you say because many CRD units have filters in the engine bay which makes the fuel hotter and some folk even place their aux filter in there too, that will make sure the fuel is heated twice by the engine bay. What a good idea, either it isn't such a problem or the motor comanies who make these things think it is ok. They do test such systems, it is called R&D.

RMD - The PRIMARY reason the fuel is recirculated at a high rate in CRD fuel systems, is to remove HEAT.

It is not recirculated to "polish" or filter the fuel, by a vastly increased amount.

That is only a "side effect" of the fuel recirculation system in CRD diesels.

Ron N
The fuel is recirculated in a CRD system but nowhere near the rate you mention. The other fuel filtering I mentioned has nothing to do with any CRD system at all. Not sure why you are confusing the two.

Does it matter - you lot do carry on.
Not all that relevant to how Ultra low Sulphur holds water.

garrycol,
who died and made you god, for pete's sake it's a forum. You know if you don't want to read it, then it is only the click of a button away sunshine.

If the op or moderators ask someone to stop adding to the thread, then and only then should they stop adding to the thread.

Just like you I am allowed to put my view and on this forum there are a couple of people with good internet access who just prattle on and on and on and on and on with information that is just plain irrelevant - and I will continue to do so - if you dont like it - tuff - dont read it

garrycol, your probably right, best for everyone to ignore you.

Thats your right :-)

There are raging arguments about whether the latest Ultra Low Sulphur diesel is more prone to water emulsification, or not.

I have seen some Steel Tank Industry experts argue it is a load of BS - but the majority of fuel and filtration experts, claim otherwise.

Even amongst the experts, there is still a lot of poor understanding about fuel and water emulsion, combustion, and the ingredients of diesel fuel.

The change in chemistry of the ULS diesel also resulted in a reduction in Interfacial Tension (the ability of two liquids to repel each other).
A lower Interfacial Tension allows the fuel and water molecules to bind together more tightly.
This results in a diesel/water emulsion with much smaller molecules of water held in the emulsion.

In addition - to counter the severe reduction in fuel lubricity caused by the removal of the sulphur, Lubricity Improvers are added to diesel today - along with detergents, rust preventatives, anti-wear additives, and combustion-improvement additives.

All these additives ASSIST in creating a better diesel/water emulsion, as well!
This is because ALL of these ADDITIVES are SURFACTANTS.

Surfactants have one major property - they reduce the surface tension of water molecules, thus allowing the molecules to be absorbed better.

You see the surfactant properties of detergents in action, when you have a greasy surface with water droplets sitting on it.
The water droplets are large, because they have high surface tension, due to the grease.

Once you add detergent to the greasy surface, this reduces the surface tension of the water molecules, and they then form very much smaller droplets, and are totally absorbed into the EMULSION of the water, the detergent and the grease.

Not one of the current fuel filters on the market - despite their claims - will extract the water from the emulsion in ULS diesel - simply because the water molecules are too tiny to be filtered, and too tightly held in the emulsion.

There is only one filtering process that removes these tiny water particles from the ULS emulsion - and that process is called "coalescing filtration".

A coalescing filter utilises glass fibre or poly meltspun fibres to produce filtering surfaces that effectively alter and lower the angle that the tiny water droplets approach the filtering media.

The physics of this process are complex - but essentially, the reduced angle of approach by the tiny water particles results in much better water removal from diesel/water emulsions.

Coalescing filtration involves bulky filtration units that are generally unable to be fitted to smaller road vehicles, because of their physical size.

There are units available for trucks, but I have not seen any available for 4WD's.
They may be available, but I haven't come across them.

By far the finest and most accurate "write-up" about the emulsion problem of ULS diesel, is in the link below.
This very detailed and lengthy explanation is courtesy of a filter manufacturer.

Fuel filtration - protecting the diesel engine.

Cheers, Ron.

Further to the above (to avoid too much in one post), the problems associated with diesel fuel emulsion are outlined thus;

1. The major problem with a strong diesel/water emulsion is CORROSION.

Water in the strong emulsion, that is not removed, causes corrosion of any unprotected steel component in the fuel system, when the vehicle is stopped and cools down.

The water droplet size is irrelevant when it comes to the corrosion factor.
Some people think you need large droplets of water, or a pool of water, to cause corrosion.
You don't, you only need water in any droplet size, for corrosion of steel components in the fuel system, to take place

To this end, rust inhibitors are added to the diesel to counteract the corrosion-causing ability of the water in the diesel/water emulsion.

You never get rid of water in fuel. It gathers just from condensation in the fuel tank when moist air is admitted to the tank.
All you can do is CONTROL the amount of water in the fuel via filtration and draining and by adding additives to keep it under control.

2. I have seen much misunderstanding, and simply wrong articles, written about the presence of water in the combustion process of diesels.

Simply put, very small molecules of water added to diesel in the combustion process does NOT cause engine damage - as I have seen written in numerous incorrect articles.

In fact, a diesel/water emulsion that is stable, with small water molecules held firmly in the emulsion, actually IMPROVES fuel combustion, reduces Nitrous Oxides, reduces SOOT buildup, and improves fuel economy.

It is only when LARGE molecules of water, that are NOT IN EMULSION, appears in the fuel - when it is in the injection pump, common rail or injectors - that damage can be incurred to the engine components.

Thus, the very tiny amount of diesel/water emulsion that gets through filters is not a problem in the combustion process - it is only a problem on the CORROSION angle.

Regardless, it is desirable to reduce the amount of water in the diesel at all times, to prevent problems occuring on more than one level.

With tight emulsions containing excessive amounts of water, the problem simply is, that the tiny water molecules can coelesce into larger molecules - then visible droplets - and you then have major problems commencing, as the steel fuel injection components that have very close tolerances (less than half a thou today), lose any fuel lubricant protection, and gall or seize.

If you want some extensive reading on diesel emulsion fuel burn, there is a large scholarly article below that is quite interesting.

Science Direct - water-in-diesel emulsion fuels

Cheers, Ron.

Nah, I can get intensive reading from the internet right here.

Dozer.
The reference didn’t work for me. Got fmse electronic company.

I looked at Diesel dog filters and many appear as 30micron which are useless for your purpose. The 2 or 5 is better BUT any which are specifically, made for a vehicle with it’s own special bracket are more than twice the price of what they should be. Twice the price pays for a few replacement filters don’t you think? They should mention a dewatering feature and give a % of emulsified water which they can remove.

DOZER
A Water Watch unit is worth having and it does work and does catch large gobs of water and alert you to water in the fuel. If I had one I would fit it for that reason. Because it doesn't actually try and prevent water continuing on it's way means something else should also be employed. ie, for emulsified water a filter which attracts, collects and precipitates the emulsified water into the bowl.
The actual particulate filtering employed is also needed.

I know of one V8 cruiser which had a filter light illuminate, rang dealer and was told to drive to nearest dealer for attention. Too late mate, the fuel system suffered failure before getting to dealer. So just one filter may not do the job. Ok normally, but since Toyota service doesn't change filters very often and only when a light come on isn't much of a way to ensure longlife.

I know folk use a 30 micron pre filter, but that is suited to old diesel units and not CRD systems at all. Not worth having as all the garbage it lets through still accumulates on the OE filter which is probably around 5 micron. Hardly a graduated approach to filtering.

Allan, this following statement from the article you linked to, is a load of rubbish, and makes one wonder at the writers understanding of the combustion process.

" As emulsified water reduces the diesel’s ability to completely combust, plus reduces lubricity, it will eventually cause damage to engine components whilst also reducing engine efficiency."

A diesel/water emulsion makes for a substantially-improved combustion process, with lower levels of Nitrous Oxides in the exhaust, an improved fuel burn, and improved fuel economy.

However, the emulsion is required to be stable and the amount of water in the emulsion has to be controlled to not become excessive.

It is only when the water in the emulsion becomes excessive, and coalesces into larger droplets, that it starts to interfere with the injection and combustion processes.

A good scholarly article on diesel emulsion fuel, is in the link below.

Science Direct - water-in-diesel emulsion fuels

Cheers, Ron.

.
Ron.

How are we, all presumably laymen, able to make a considered judgement when, as you say above.... "Even amongst the experts, there is still a lot of poor understanding about fuel and water emulsion, combustion, and the ingredients of diesel fuel."?

How do we appraise the paper by Vellaiyan et al that you linked to. Are they the Right Experts or the Wrong Experts? Do we applaud one or the other based on whether we like the sound of their assertions? Personally, I thought the website that I linked to looked very nice.

Fortunately, I can avoid all these difficult decisions by driving a Troopy with a simple 1HZ engine. And I expect that it will outlast me, after all, it is somewhat younger. lol

Allan, there's a lot of articles written by "experts", and posted on the 'net, that contain untruths, or show a glaring lack of knowledge.

It certainly is a struggle to try and determine who is correct, and who is lacking knowledge, and who is pushing an "agenda".

As the old saying goes, the definition of an "expert" is that the word is made up of two conjoined words - "X" and "spurt" - with "X" being scientifically defined as the "unknown value", and "spurt" scientifically defined, as a drip under pressure! LOL

You know, you stand to become a real old dinosaur, running on dinosaur juice, if you continue to own and run that old 1HZ! - particularly when one of those "new-fangled" electric 4WD's, or SUV's zips past you! LOL

Cheers, Ron.

If people fitted a water alarm and suitable micron sized large capacity pre filter which dewaters as well, the fuel rate through that large filter will be slower and more efficient than many of the popular filters "pushed by diesel expert places" (there are good ones and bad ones) some of which are too big in micron to do anything much. That way most people will have motoring success without undue cost and don't have to be a diesel scientists or glued to the internet and google to drive out of town.

SImple.

.
Ron, I already am an "old dinosaur".
And while those new-fangled vehicles zip past, I am smelling the wildflowers.

But me and The Troopy will possibly live beyond them and all their drivers!
If I can survive an 'electrical thread', I can survive anything.

If I DID have to worry about diesel fuel matters, then I would place my money on your opinion.
For one thing, you know how to spell. lol

Ron, I seem to recall there was a great deal of testing carried out on diesel engines with a water injection system to aid combustion and reduce emissions. I can't remember where I read this (old timers decease LOL), and it was a while ago.

Macca.

Excellent article by blokes in "the know", and who see and have to fix the problems associated with todays high-tech fuel systems - that are very susceptible to damage from the tiniest amounts of contaminants, that didn't affect the old mechanical fuel injection systems.

Cheers, Ron.