I have spent a good few years around diesel engine installations, automotive, industrial, power generation. Nothing compares with marine, requires a totally different mind set to build a fuel system which will ensure vessel is free of breakdown due to contamination.
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.
For example;
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.
Paul
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