Know Your Supply Tubes

BrianAtSmarty

BrianAtSmarty

SmartyResource
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Aug 13, 2012
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432
Know your supply tubes



Internally contained in the Supply tube is the Edge Filter. The Edge Filter is a safety feature, built into the supply tube. It is designed to break particles larger than 50 µm into smaller pieces to avoid major malfunctions like continuous injection, blocked nozzle holes, amongst other things that can cause catastrophic engine failure. Contamination smaller than 50 µm will still cause damage to your injectors and reduce their lifetime. Careful inspection of the edge filters will tell you about your fuel quality and filtration system.

If your supply tubes look like new:

edgefilternew.png


Indicates the good quality of fuel that you use, with a proper fuel filter and proper filter interval changes.






If you have slight wear traces on it:

edgefiltertraces.png


This tells you that you get a lot of particles in your injectors and you should change your fuel filter more often.





Flow channels built on the edge filter:

edgefilterchannel.png




You have serious problems with your fuel quality. You should change the location where you buy your fuel. Often times the dirt gets into the fuel at the petrol station, by having leakage allowing dust into their fuel tanks. Or you do not use the correct filter for your application or change your fuel filter often enough.

Many people think that an older fuel filter will filter more than a new one, because the orifices on the filter material are getting closed or smaller, but that is simply wrong. An older filter will reduce the flow through it, which causes a bigger pressure resistance of the filter and a bigger delta pressure between the inlet and the outlet of the filter. This leads to the fact that bigger particles are getting pressed through the filter material and the effectiveness of filter is getting lower and lower and the number of particles getting to your injectors is increased.

In order to inspect your edge filter, it must be pressed out of the inlet end. Once removed, both the supply tube & edge filter are NOT reuseable !
 
Nice write up.....the pics really show the truth. Thanks for that.

Sent from my XT1080 using Tapatalk
 
So how do you get them out? Cut in half? Got any more pictures with the whole tube?
 
Yeah and if you remove them and have Dual 2 micron filters can you run them with out?
 
They are in there pretty tight. If you press them out that makes the tube unusable. I would not take the risk.

What is recommended by the top man at BBi is to choose one tube at the time of your injector R&R and press out and inspect. If that one is in excellent shape simply use another new one to replace, then replace the other 5 used ones. If it is damaged then replace all 6.
 
dangerous06 said:
Yeah and if you remove them and have Dual 2 micron filters can you run them with out?
Click to expand...

Cp3's like to puke metal crap every once in a while and they are the last defense for that. New injectors should just get new tubes period. You can't check one and assume the rest are good.

We had a pump $hit the bed on the dyno, and put steel through the hole system, I checked every cross tube and two did not have a single flake in them, the other 4 were just full of it. Surprisingly injectors survived.
 
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great pics brian. ive never seen it like that before!

i change my 2 micron's out of bordem, better safe than sorry
 
I'm just curious about how with industry standard training from many, many manufacturers, this is the first time EVER that I (or any of the other technicians I have access to) have heard claimed that differential pressure across a filter will cause particles larger that the filter is rated for to migrate through the filtration media. (without a catastrophic failure of the element)

It is far, far, far infinitely farther more likely that contamination is occurring at the time of a (frequent?) Filter change.

So, to that, I would ask that you substantiate you claim of filtration failure of the media.

Keep in mind that I'm not contending the information you have provided. Simply the mode in which it occurs.

Monkey Fist Rage
 
Well here is some useful information I have from one “in the know”. A 2 micron filter never filters %100 of all particles bigger than 2 micron out of your fuel. Whether new or a filter with miles on it, much bigger particles will be able to pass thru the filter.

A filter has always had a defined filtration efficiency. For example 97% of all particles between 2 and 2 microns stay in the filter, 3% will pass thru, 98% of all particles between 3 and 4 micron will be caught in the filter, 1% will go on thru and so on. (This is just an example)

The longer the filter stays in the truck, the more particles get filtered out of the fuel and stay in the filter. The filter material will get filled up with material and the resistance of the filter will rise and the pressure delta between inlet and outlet and outlet gets higher. This leads to the fact that the efficiency of the filter will decrease. For example, instead of collecting 97% of particles between 2 and 3 micron it will only collect 85% of these particles so more particles do pass thru the filter.

It has been found that filters with much too high flow resistance, which lead to cracked filter material, the filter does not filter any more. You will have 100% of the debris passing thru your filter.

One risk changing your filter is the possibility of debris being introduced into your fuel system so one can not do a filter change carelessly. Lets say you get 100 particles into your fuel system accidently while doing a filter R&R! Not what you want to do, however that is nothing when you compare that to getting 100 particles an hour into your system thru a fuel filter which is not filtering correctly.

Here is a link for you gentlemen which you may find useful.
http://www.machinerylubrication.com/Read/1289/oil-filter-efficiency
 
The filter material will get filled up with material and the resistance of the filter will rise and the pressure delta between inlet and outlet and outlet gets higher. This leads to the fact that the efficiency of the filter will decrease. For example, instead of collecting 97% of particles between 2 and 3 micron it will only collect 85% of these particles so more particles do pass thru the filter.
Click to expand...

The pictures you posted are great. Did you cut a cross section to be able to photograph? Or did you use a non-destructive method to image?

I think there is a misunderstanding concerning how most of our fuel systems are setup. I think I could generalize that most trucks of people on this board have a regulated low-pressure lift pump fuel supply. The main fuel filter (2 micron or whatever) is installed between the lift pump and the high pressure pump. The lift pump delivers a maximum pressure based on what it's regulated to. The filter state (clogged, not clogged, partially clogged) doesn't have much effect on the pressure the lift pump puts out.

Sure, as the filter becomes plugged, the pressure drop across the filter increases. But it doesn't increase because the pressure going into it increases. The delta increases because the pressure coming out drops. I don't think there's ever a case where the pressure into the filter would just keep climbing until it forced particles through a clogged filter or burst the media. On the contrary, I've witnessed a good number of clogged filters starve the engine of fuel to the point that it doesn't run. This obviously is a good thing, as the filter protected the engine...instead of allowing agglomerated particles which burst through the filter media to be sent downstream.
 
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ENafziger said:
The pictures you posted are great. Did you cut a cross section to be able to photograph? Or did you use a non-destructive method to image?

I think there is a misunderstanding concerning how most of our fuel systems are setup. I think I could generalize that most trucks of people on this board have a regulated low-pressure lift pump fuel supply. The main fuel filter (2 micron or whatever) is installed between the lift pump and the high pressure pump. The lift pump delivers a maximum pressure based on what it's regulated to. The filter state (clogged, not clogged, partially clogged) doesn't have much effect on the pressure the lift pump puts out.

Sure, as the filter becomes plugged, the pressure drop across the filter increases. But it doesn't increase because the pressure going into it increases. The delta increases because the pressure coming out drops. I don't think there's ever a case where the pressure into the filter would just keep climbing until it forced particles through a clogged filter or burst the media. On the contrary, I've witnessed a good number of clogged filters starve the engine of fuel to the point that it doesn't run. This obviously is a good thing, as the filter protected the engine...instead of allowing agglomerated particles which burst through the filter media to be sent downstream.
Click to expand...

Thank you someone who is ACTUALLY in the "know".

To elaborate even further, what is the possibility of fuel starvation from an "overdue" filter causing fuel starvation, then the injection pump starts to spall due to lack of lubricity, and damn if you don't end up with particles where they don't belong.


Let me ask this. Why would you spontaneously post this information?

Are you suffering an unacceptable failure rate and NEED this information to be true? Because you certainly aren't the first individuals to suffer the reality that fuel supplies just aren't up to the task of sustaining modern fuel injection systems (diesel or otherwise).

Yes, your filtration efficiencies are accurate if memory serves. It is a diminishing return.

Discuss.....


Monkey Fist Rage
 
as to why he posted, he was told to do so, and supplied the cut and paste article........ as usual.
 
ENafziger said:
The pictures you posted are great. Did you cut a cross section to be able to photograph? Or did you use a non-destructive method to image?

I think there is a misunderstanding concerning how most of our fuel systems are setup. I think I could generalize that most trucks of people on this board have a regulated low-pressure lift pump fuel supply. The main fuel filter (2 micron or whatever) is installed between the lift pump and the high pressure pump. The lift pump delivers a maximum pressure based on what it's regulated to. The filter state (clogged, not clogged, partially clogged) doesn't have much effect on the pressure the lift pump puts out.

Sure, as the filter becomes plugged, the pressure drop across the filter increases. But it doesn't increase because the pressure going into it increases. The delta increases because the pressure coming out drops. I don't think there's ever a case where the pressure into the filter would just keep climbing until it forced particles through a clogged filter or burst the media. On the contrary, I've witnessed a good number of clogged filters starve the engine of fuel to the point that it doesn't run. This obviously is a good thing, as the filter protected the engine...instead of allowing agglomerated particles which burst through the filter media to be sent downstream.
Click to expand...

^^this guy gets it. :thankyou2:
 
ENafziger said:
The pictures you posted are great. Did you cut a cross section to be able to photograph? Or did you use a non-destructive method to image?

I think there is a misunderstanding concerning how most of our fuel systems are setup. I think I could generalize that most trucks of people on this board have a regulated low-pressure lift pump fuel supply. The main fuel filter (2 micron or whatever) is installed between the lift pump and the high pressure pump. The lift pump delivers a maximum pressure based on what it's regulated to. The filter state (clogged, not clogged, partially clogged) doesn't have much effect on the pressure the lift pump puts out.

Sure, as the filter becomes plugged, the pressure drop across the filter increases. But it doesn't increase because the pressure going into it increases. The delta increases because the pressure coming out drops. I don't think there's ever a case where the pressure into the filter would just keep climbing until it forced particles through a clogged filter or burst the media. On the contrary, I've witnessed a good number of clogged filters starve the engine of fuel to the point that it doesn't run. This obviously is a good thing, as the filter protected the engine...instead of allowing agglomerated particles which burst through the filter media to be sent downstream.
Click to expand...

The fuel filters in a common rail truck are in a low pressure line. But while the lift pump is building up pressure, the high pressure CP-3 pump is reducing pressure on the downstream side of the fuel filter.



The delta pressure discussed is very little, and although in a low pressure line, it is enough to reduce filter efficiency.
 
BrianAtSmarty said:
The fuel filters in a common rail truck are in a low pressure line. But while the lift pump is building up pressure, the high pressure CP-3 pump is reducing pressure on the downstream side of the fuel filter.



The delta pressure discussed is very little, and although in a low pressure line, it is enough to reduce filter efficiency.
Click to expand...



How? Does the filter move out of the way?
 
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