I have an old and out of use Smiths CAV secondary double filter and water separator unit.
Would this be a suitable basis for a fuel polishing system ?
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Thread: Fuel Polishing
02-05-12, 14:34 #41Registered User
- Join Date
- Jun 2011
02-05-12, 22:55 #42Jeanneau Merry Fisher 805 For Sale. www.gooch.co.uk
07-05-12, 15:50 #43
Paul, I think we will have to agree to differ on this.
08-05-12, 06:37 #44Registered User
Location : Somerset
- Join Date
- Feb 2008
The filters you quoted as using are simply inadequate for the job. I looked at the applications, little Yanmar 3TNE up to Land Rover 2.5 and VM 2.5. These are widdy tractor and automotive applications.
Please please read up on filteration. The stuff you are using is not Beta rated, neither is Racor stuff for that matter which is my beef with them.
OK micron ratings are how oil, fuel, hydraulic and other liquid filters efficiency are measured. A human hair for instance is 40-80 microns, or more relevant mould spores 10-30 microns.
When talking about micron ratings there are two different ratings commonly referred to or given to a filter.
The nominal rating which is the smallest size particle the filter will catch 50% of the time on a consistent basis. The nominal rating is just a way to get a lower number in the marketing and really doesn’t mean anything to you and I.
Your preferred filter CLAIMS to filter down to 5-7 microns. That means that 5-7 microns is the smallest particle it will catch 50% of the time.
The next and most important rating is the absolute rating. The absolute rating is the smallest particle the filter will catch 98.7% of the time. This is the rating you should be asking for when you are researching your filters.
However my explanation of the absolute ratings needs to be broken down a little more. Beta ratios and how they work as they are critical to really knowing how the filter can actually perform and are not as easily manipulated as a nominal or absolute number can be the unknowing consumer.
“Nominal” ratings are ok when nothing else is known; as some info is always better than no info. And “nominal” ratings can help compare one filter to another, but only at 50% efficiency.
There is a much better way to compare filters, though. Beta ratios are a multi-level rating of the efficiency of a filter. Some filters can be very good at one particle size, but poor at another. Beta ratings allow us to understand how a filter performs overall. While it is not an exact correlation, it can be presumed to reasonably represent both the “nominal” and near-absolute ratings.
Beta ratings are read in a particular way, and some basic math must be applied. Betas are stated as two fractions, each representing a ratio. Please understand that it is NOT the actual fraction you are using, but rather the numbers as individual values. They are merely stated as a “fraction” for the purpose of easy notation.
You must take the first number (upper number) as an inverse to the number “1” (one), and then subtract that resultant percentage from a whole of 100%. This applies for the upper and lower numbers individually. Then you use the second fractional value as individual number to know what micro size the rating is stated at.
Beta rating of: “2 / 20 = 13 / 23”
The “2” is taken as a percentage, when divided into “1”; i.e. 1 / 2 (one-half), or 50% missed. So 100% particles minus 50% missed = 50% caught.
The “20” is taken as a percentage, when also divided into “1”; 1/20 (one-twentieth) or 5%. So 100% particles minus 5% missed = 95% caught.
The “13” is the particle size at the 50% rating. In other words, 50% of the time the filter catches particles that are at, or larger than, 13 microns in size.
The “23” is the particle size at the 95% rating. In other words, 95% of the time the filter catches particles that are at, or larger than, 23 microns in size.
Using this formula allows you to understand how a filter does its job with both large and small particles, and how efficient it is at those particular ratings. It is a much better view of the filter’s abilities as a whole.
Cat and Cummins focus on the Beta ratio not just measurement of microns, take a look at this Cat publication. http://www.pon-cat.com/Global/Pon%20...epslanguage=en
Used to share a beer or two in Africa with local Cat guy. Most of large power generation on mine sites was pretty equal split of Cat 3512 or Cummins KV60 with few interlopers from Deutz, Mitsubishi or MTU. Interlopers were always in trouble, mainly with injectors.
If Cat or Cummins hit injector problems we could be over 90% confidant operators playing silly games cutting corners with filteration. Mine site would say we only get this problem with your engine. Quick call to Cat guy would confirm that they were also having injector issues. Kevin the Cat guy always drawled no such thing as too much filteration.
If Trundlebug makes his fuel polisher into a properly installed system it will be totally effective AND cost less to maintain and not grind to a halt if he is hit with a bout of microbial contamination.
Just remember the Cat guy......No such thing as too much filteration. And boats requre totally different approach to filteration.
Last edited by Latestarter1; 08-05-12 at 06:41.
08-05-12, 10:34 #45
Thanks for the info Paul very interesting.....
However I stand by what I know works and at an economical expense. Most of the guys on here are running quite small engines compared to what you have delt with and need a cost effective way of reducing the risk of contamination, the set up I fitted/use delivers that remedy by continually filtering the fuel and hopefully catching the contaminates befor it goes into the fuel delivery side to the engine.
If I have problems I'll call you and you can say I told you so!
As I said...... I think we will have to agree to disagree.
Now what do you know about chemical treatments for fuel bug removal
Last edited by LittleShip; 08-05-12 at 10:36.
08-05-12, 10:53 #46
Your above post for example regarding engine filtration is lost in a polishing post.
Out of interest could little ship remove his cav filters and replace with a prefilter that is designed to remove emulsified water (FS1000 or similar) and then use his old cavs for fuel polishing, as far as I can tell littleship only has protection from free water and he is asking about treatments which will turn some of the water from free water to emulsified water which is free to pass through his current pre filters and engine filters.
The reason I ask is in particular to fuel polishing because I think most of us regard fuel polishing just as an exercise to reduce free water and sludge from the tank , we know the fuel will not be 100% clean, we leave the prefilter and engine filter to take care of that.
I have addressed my post to Paul , Tom as I am not at all sure on this but I think you currently run the risk of allowing water (emulsified) through your injectors, as we use older more stale fuel and more vegetable fuel into our tanks we will become more and more at risk of larger levels of water..
08-05-12, 11:16 #47
These are the filters I use before the small CAV mounted engine filters.
As you can see they do have water seperation.
I have one I use to continuously filter from the tanks (Polish) and one as a pre filter for the fuel line. I have two seperate fittings on each tank so the bottom ones draw fuel into the filter and return back to the tanks. The higher connection (about 1") draws fuel into the pre-filter and then on to the engine filters (small CAV on the engine).
I'm not sure Paul understands my set up, maybe he does and still dosent like it
I agree the info would be better as a seperate post and probably as a sticky at the top of the section.
Asking about chemical addatives was just to throw a spanner in
Last edited by LittleShip; 08-05-12 at 11:19.
08-05-12, 11:47 #48
I accept this is all so mixed up its difficult to follow who is talking about engine filters/pre filters and fuel polishing.
Most water separators are only designed to remove free water.
Water becomes emulsified by the use of additives (some now added at source ) and by the actions of fuel pumps.
Depending on the type of filter you are using then the emulsified water is most likely free to pass through your filter.
Cellulose paper ..........are not designed to remove water, only the action/design of the filter case will remove free water.
Treated paper........... designed to remove emulsified water
Stratopore(as used in FS1000)............ I rely on this for my prefilter as being superior to my engine filter.
Last edited by DAKA; 08-05-12 at 11:52..
08-05-12, 21:12 #49It all started with a rowing boat......
08-05-12, 21:15 #50Jeanneau Merry Fisher 805 For Sale. www.gooch.co.uk