Racor 1000 filter change interval?

O C Diver said:

You put an awful lot of faith in a cheap vacuum gauge.

The other part about changing them annually is that even though the engine hasn't quit, you can see how close you are to a plugged filter. Maybe you got a bad load of fuel and it's time to decide if you're going to be going through some filters before the crud is out of the tank.

Now I fully realize that you could pull the filter, check it, and put it back in. If I'm going to the trouble of pulling the filter, for $10 or less in bulk, I'm putting a new one in. When it comes to filters, I'm happy to spend money.

Ted

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"You put an awful lot of faith in a cheap vacuum gauge"
FWIW - the vacuum gages in our past 3 boat have been very accurate for diagnostics and well as filter changes.
On one occasion with a new filter installed the gage 'told' us that ridiculous check ball was stuck in the filter track.
In another case just after a new filter was installed we saw high pressure and tracked down a pinched fuel line.
They work and are very valuable for not much expense....

Thanks Delfin...

Delfin said:

You appear to be the only one who thinks the OP's reading of the vacuum gauge took place under no load. He doesn't appear to say that, but perhaps I missed it. The gauges work just fine when used as directed, like most equipment in widespread use does.

From Racor:

Monitoring the black needle to ensure it does not reach this setting has been difficult as the operator must observe the needle while the engine is running at service speed (the gauge is not always mounted in a location that is easy to monitor).

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Thank you for confirming that Racor confirms that the vacuum gauge is useless when the engine is running under no load.


Still, Racor's dumb language adds to the confusion.


When I say "the vacuum gauge is useless when the engine is running under no load" and Racor says "...the operator must observe the needle while the engine is running at service speed", how are those different?


Here's how they are different.


For someone who normally runs at 1,800 rpm, they >>might<< think that running at 1,800rpm in neutral this is the same as "running at service speed". This is not true. When the engine is running at 1,800 rpm under no load, it is barely drawing more fuel than it would running at idle under no load.


This is a common misconception I have wittnessed dozens of times here on trawlerforum and pretty much everywhere else I go. Folks just can't seem to grasp the idea that engines draw fuel in proportion to the load presented -- not the rpm spinning. The load on a diesel engine determines how many GPH it is pulling, not the RPM!

Re: "You appear to be the only one who thinks the OP's reading of the vacuum gauge took place under no load."


All I had to do was look at his filter photos to know. That, and seeing dozens of people make the same mistake over the last 30 years or so (including me, once upon a time).

Riverguy said:

Thank you for confirming that Racor confirms that the vacuum gauge is useless when the engine is running under no load.


Still, Racor's dumb language adds to the confusion.


When I say "the vacuum gauge is useless when the engine is running under no load" and Racor says "...the operator must observe the needle while the engine is running at service speed", how are those different?


Here's how they are different.


For someone who normally runs at 1,800 rpm, they >>might<< think that running at 1,800rpm in neutral this is the same as "running at service speed". This is not true. When the engine is running at 1,800 rpm under no load, it is barely drawing more fuel than it would running at idle under no load.


This is a common misconception I have wittnessed dozens of times here on trawlerforum and pretty much everywhere else I go. Folks just can't seem to grasp the idea that engines draw fuel in proportion to the load presented -- not the rpm spinning. The load on a diesel engine determines how many GPH it is pulling, not the RPM!

Re: "You appear to be the only one who thinks the OP's reading of the vacuum gauge took place under no load."


All I had to do was look at his filter photos to know. That, and seeing dozens of people make the same mistake over the last 30 years or so (including me, once upon a time).

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That's impressive. Although the OP never says he reads his gauge under no load (who does, anyway?), you can divine he is and when telepathy fails, you can also do so just by looking at a dirty filter. Wow.

smitty477 said:

"You put an awful lot of faith in a cheap vacuum gauge"
FWIW - the vacuum gages in our past 3 boat have been very accurate for diagnostics and well as filter changes.
On one occasion with a new filter installed the gage 'told' us that ridiculous check ball was stuck in the filter track.
In another case just after a new filter was installed we saw high pressure and tracked down a pinched fuel line.
They work and are very valuable for not much expense....

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To be clear, I have them and watch them, but it's still a pretty low quality gauge. Have seen more than one fail to read at all with a plugged filter. See Ski's comments below.

Ski in NC said:

I think most are cheaply made and seen several that did not work. Either gauge in hand showed high vac (impossible) or close off supply valve and gauge did not rise even though suction flow blocked (note this trick does not work on dual racors with single selector valve). Also found one gauge that leaked under suction and caused an engine stall and related "cap'n crunch".

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Ted

Riverguy said:

Well, yes. Whether the OP's filter is clean or dirty, that vacuum gauge is useless when the engine is under no-load.

Think it through. A Racor 1000 is a 180gph filter. At idle or no-load off idle, the engine in question will be drawing less than 1gph (about 0.5% of the Racor's flow capacity).

I said that any time this engine is running under no-load, the vacuum gauge will be useless. This is because, under no-load, if the vacuum gauge starts increasing, it means you should have changed the filter a loooonnnngggg time ago.

I know this seems counter-intuitive. Maybe it will help if I say it differently.

If you begin showing increasing vacuum on a 180gph filter, when you are only pulling 0.8gph through the filter, it means the filter is TOTALLY plugged. It means the filter was WAY overdue for changing.

That is why the vacuum gauge is useless when there is no load on the engine. If you wait until you see vacuum increasing at no-load, it is long past time that you should have changed the filter.

If you read the thread from the beginning, you will see this is exactly what happened here.

The whole gist of OP's question is:

Q. "why didn't my vacuum gauge tell me that my filter was totally plugged?"

A. Because your vacuum gauge readings were taken when the engine was not sufficiently loaded, and under these conditions, your vacuum gauge is useless.

Yes, I am belaboring the point, because this is yet another very common misconception that causes significant safety concerns. It is a misconception that is common even among very experienced boaters!

Why is it a safety concern? If one is only looking at their filter's vacuum gauge when the engine is under no load, they will have no idea when the filter becomes significantly plugged. They will then be surprised when they need power from the engine (outrunning a storm or navigating a tricky pass) and it's not there.

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I do something I am certain is very uncommon but simple and foolproof. My boat has Davco filter housings. These are very common to the trucking industry. The time to change the filter is when the fuel reaches the top of the clear housing. No need for a vacuum gauge. No need for guessing. No need for prematurely changing out a perfectly good filter. Bonus - changing filters is a simple, no-mess task.

catalinajack said:

I do something I am certain is very uncommon but simple and foolproof. My boat has Davco filter housings. These are very common to the trucking industry. The time to change the filter is when the fuel reaches the top of the clear housing. No need for a vacuum gauge. No need for guessing. No need for prematurely changing out a perfectly good filter. Bonus - changing filters is a simple, no-mess task.

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Those are very cool.

IF in doubt, change the filter. You dont want the engine to stall at a 'most inconvenient' time such as riding a wave through a cut. You might turn side ways if the engine stalls and sideways is not a good thing.

Filters are cheap insurance.

AND, when was the last time you had your vacuum gauge calibrated?

Riverguy said:

2) I think you are probably wasting time and effort by running new fuel through the 2 micron 'polishing' before adding to your tanks. Most of what you are seeing is microbial biofouling, and this is growing inside your tanks, not as a result of contaminated fuel. This is a common problem that is particularly prevalent in high-humidity climates and where tanks are not normally kept full. Humidity in the air condenses on the inside surfaces of the tanks and the condensate water feeds the growth of the microbes. There is a good white paper on this at http://www.hpcdfuel.com/pdf/DOWfuel_training.pdf

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This is often proposed in theory and seldom tested. But Maine Sail (CMS) has tested it. It does not happen, at least in his tests.

IF you are blessed with a polishing system, you can put the polisher on and let it run to your hearts content. SMILE

"(the gauge is not always mounted in a location that is easy to monitor)."

If the gauge is located in the Hell Hole on top of the filter , it might be dangerous to change out the plugged filter with the engine operating.

At best it will be loud and over 100F , moving the filter bank to a location out of the HH only requires some hose.

O C Diver said:

To be clear, I have them and watch them, but it's still a pretty low quality gauge. Have seen more than one fail to read at all with a plugged filter. See Ski's comments below.



Ted

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I have found fairly robust gages pretty easy to find and install - similar to any engine gages that you will want to utilize it is best to have good indicators - rpm, boost, pyro, oil pressure etc. If they seem weak or are failing they need to be replaced with a suitable replacement.
The last 10 or so vac gages I bought were very good and not too expensive at all - 2" Stainless steel case, + or -2% accuracy, and I added snubbers and glycerin filled them for better use and protection - I think they were less than $30 each at the time. Would not want to cruise without any of the gages in good working order as they are a big plus when you need them.

FF said:

"(the gauge is not always mounted in a location that is easy to monitor)."

If the gauge is located in the Hell Hole on top of the filter , it might be dangerous to change out the plugged filter with the engine operating.

At best it will be loud and over 100F , moving the filter bank to a location out of the HH only requires some hose.

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IMO, never do anything to a running engine unless you want to lose a body part.

You guys are way over-thinking this filter thing. Unless you have taken on a load of bad fuel, you can see the level of crud in a Racor in the bowl. If the engine slows uncommanded under load, flip the lever. If you haven’t changed that filter, for a while, change it in a safe place later but that gauge is adequate. ANY reading not zero and it’s time to change. Has anybody ever seen a “deteriorated” filter? Of course not; crap in an engine from a failed filter would bankrupt Racor, they don’t use any filter compound that “fails.” How else to sell filters to boat owners that only do 100 hours a year? Tell them they fail over time. Codswallop.

Xsbank said:

You guys are way over-thinking this filter thing. Unless you have taken on a load of bad fuel, you can see the level of crud in a Racor in the bowl. If the engine slows uncommanded under load, flip the lever. If you haven’t changed that filter, for a while, change it in a safe place later but that gauge is adequate. ANY reading not zero and it’s time to change. Has anybody ever seen a “deteriorated” filter? Of course not; crap in an engine from a failed filter would bankrupt Racor, they don’t use any filter compound that “fails.” How else to sell filters to boat owners that only do 100 hours a year? Tell them they fail over time. Codswallop.

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"ANY reading not zero and it’s time to change."
I am confused by this....
- most all vac gages I have used and installed have a 'new' reading of 2-3" , so there is no zero ever.
- a 'good' filter in use will trend thru 3-8" over use and not be near a point requiring replacement.
- at about 8" I typically plan on when to change for convenience sake and make life easier, filters reading 11-12" still do not stop my engines.

smitty477 said:

"ANY reading not zero and it’s time to change."
I am confused by this....
- most all vac gages I have used and installed have a 'new' reading of 2-3" , so there is no zero ever.
- a 'good' filter in use will trend thru 3-8" over use and not be near a point requiring replacement.
- at about 8" I typically plan on when to change for convenience sake and make life easier, filters reading 11-12" still do not stop my engines.

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You're correct. There will always be a baseline vacuum, usually around 7 - 10 inches of Hg when running at the operating rpm. I believe Racor says to change the filter when it gets 5 or so inches above that range.

All this change or not to change IMO over looks one point. How much water is in the bowl.

OldDan1943 said:

All this change or not to change IMO over looks one point. How much water is in the bowl.

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I have never seen any water in the filter bowls - but we always had separate inline water separators for water - which were always empty as well.

Delfin said:

You're correct. There will always be a baseline vacuum, usually around 7 - 10 inches of Hg when running at the operating rpm. I believe Racor says to change the filter when it gets 5 or so inches above that range.

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Always best to check the engine manufacturer's spec on maximum fuel pump lift or vacuum. An odd one is the C series Cummins which have a surprisingly low vacuum limit. Exceeding that pumps limit can damage the pump.

Ted

Codswallop.

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Xs you gotta explain what this means.

Definition of codswallop



British
: nonsense


Mr. X is from BRITISH Columbia, after all...

DDW said:

This is often proposed in theory and seldom tested. But Maine Sail (CMS) has tested it. It does not happen, at least in his tests.

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I'd seen this test a few years ago, is this the one you are talking about?

https://www.pbase.com/mainecruising/fuel_tankt_condensation


Condensation and dew-points are not theories, they are laws of nature. This test is nonsense.


In the same way that an empty, open beer can will never generate condensate inside, this test was guaranteed to never generate condensate inside the aluminum fuel tank. Also, the author appears to not understand the concept of a "dew point".

Missing elements:

No thermal ballast: His tank was empty so there was nothing inside it to keep the aluminum surfaces cool as temperatures rise above and below the dew point. Next time you see condensate on a cold beer can, note how it does not immediately stop forming immediately above the liquid level. Aluminum conducts heat (and cold) pretty well.

Environment/Ambient temperature: Marine fuel tanks sit in a bilge, close to the waterline, where water temps usually keep them cooler (or warmer) than the outside air coming in through the fuel vent. All of that sound insulation under your cabin sole is also good thermal insulation. I keep a temp/humidity sensor in my bilge -- temps down there are always close to the ambient water temps and in some cases 20 degrees lower than outside ambient. Here in Florida, this means that the dew-point will coincide with the temperature of the aluminum gas tanks almost every morning, and water will condense on them because it simply must do so.

Any time a cold surface comes in contact with moisture laden air, assuming that the "cold" surface is below the dew point of the air, condensate will form. No need to waste time 'testing' this, it just IS.

Read that test again and think this through...it's quickly obvious why this test was guaranteed to generate a negative result. He just doesn't 'get' the physics here.

Now...forget about condensation for a moment. In many environments (in less humid areas), the primary way that moisture gets into fuel is by direct absorbtion of moisture from the air. The more "wet air" that your tank is breathing in, the more moisture the fuel will absorb. The more air that is in your tanks, the more the tank will breath as air expands and contracts with temperature. For me, the main reason for keeping tanks full is to make their "lungs" smaller. Less air in the tank, less expansion and contraction of air and less 'breathing'.

Condensation in the tank is a problem in some environments, moisture in the fuel is potentially a problem in all environments.

My main point is that everyone who is storing more fuel than they are burning in a month (and I think that's all of us at some point) needs to add a biocide agent, because there WILL be water in that fuel, and the bugs WILL find it.

Keeping tanks full will help slow down the absorbtion of moisture, but won't prevent it. Also, keeping tanks full will increase the total amount of moisture the fuel can hold in suspension before it begins to precipitate out and build up at the bottom of your tanks. I think it's still a good idea.

I believe 90% of the water problems in diesel tanks comes not from condensation, but leaky deck fill caps or bad vent plumbing.

I have two 150gal tanks below the cockpit deck, the fills are on the tanks themselves and looking through the cap you can see the tank bottom at the low point. The vents go to a separator tank that has a low point drain. I usually keep tanks only 1/4 full most of the time to reduce weight (planing hull), only fill further as needed for trips.

In 12yrs since the build, I have had absolutely zero water in the tanks or the Racor.

If condensation was an issue, I would have seen water and I have not.

My biggest issue is condensation on the outside of the tanks when we get a warm front.

Ski is correct ( you beat me to it!) internal tank condensation is immaterial. The volume of moisture in the air and the volume of air in the tank cannot support enough condensation to lose sleep over - that is also physics. Measure how much air migrates in and out with temperature change and measure how little that small amount of air can hold. Besides, the tanks are more effected by water temperature which does not fluctuate as much as air temperature. Fuel from the refinery contains water, look up the msds for the fuel; not significant unless you take the fuel high in the air to -65 degrees, then you need fuel heaters etc. Racor, if sized properly, will spin out excess water and they also have some sort of membrane/coating that works like goretex as a barrier to water. As has been stated, water gets in the tank from faulty fittings or from the marina’s tanks.

Sorry you didn’t like codswallop. How about poppycock? Horsefeathers? Truck; that’s probably Mark Twain?

RT, “...nations divided by a common language...” Thanks for translating.

I've two thread related questions. What micron rating is OP's filter in the picture with the first post? He says both 2u and 10u are used. Secondly, is the filter pictured before or after the onboard day tank?

Two likely irrelevant comments. I've first hand knowledge of a Nordhavn 55 that had all it's fuel tanks, including the day tank, completely "bug" fouled due to old fuel loaded on from a South of the border location. Secondly, spin on 30u filters, from a shore location I'm familiar with, routinely pass 20,000 to 30,000 gallons before they are changed on an approximate monthly timed, not loaded, basis.

Lastly, can a tank and filters grow cultures by merely sitting if tanks and fuel are "bad" due to water, age or bad shore fuel to begin with.

sunchaser said:

I've two thread related questions. What micron rating is OP's filter in the picture with the first post? He says both 2u and 10u are used. Secondly, is the filter pictured before or after the onboard day tank?

Two likely irrelevant comments. I've first hand knowledge of a Nordhavn 55 that had all it's fuel tanks, including the day tank, completely "bug" fouled due to old fuel loaded on from a South of the border location. Secondly, spin on 30u filters, from a shore location I'm familiar with, routinely pass 20,000 to 30,000 gallons before they are changed on an approximate monthly timed, not loaded, basis.

Lastly, can a tank and filters grow cultures by merely sitting if tanks and fuel are "bad" due to water, age or bad shore fuel to begin with.

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"Lastly, can a tank and filters grow cultures by merely sitting if tanks and fuel are "bad" due to water, age or bad shore fuel to begin with."
Fuel can degrade over time with no microbial action and form long chain hydrocarbons as a result - it takes years,
Fuel can support microbial action if there is a fuel/water interface in the storage area of the fuel - that can develop much quicker.

Xsbank said:

Ski is correct ( you beat me to it!) internal tank condensation is immaterial. The volume of moisture in the air and the volume of air in the tank cannot support enough condensation to lose sleep over - that is also physics. Measure how much air migrates in and out with temperature change and measure how little that small amount of air can hold.

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A shore based tank farm or large yacht tanks can indeed grow water. Once into multi ten thousand or larger sized tanks condensation protocols and equipment are in place. For those of us that have purchased large volumes of fuel it is real world monitoring issue. BTW, physics doesn't apply - try chemical thermodynamics instead

Water in Diesel - Clean Diesel Solutions - Donaldson

Diesel fuel absorbs a LOT of water before you ever see it...

Ski in NC said:

...If condensation was an issue, I would have seen water and I have not.

My biggest issue is condensation on the outside of the tanks when we get a warm front.

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Hmmm...how is it that you think water can be condensing on the outside of the tanks, but not on the inside? Wet air meeting cold metal = condensation, period.



The reason you are not actually be seeing the water is because it has not precipitated out yet. Just like air, diesel fuel will "absorb" water, up to it's saturation point. Like in air, the amount of water the fuel can hold is temperature dependent. Diesel fuel can absorb a LOT of water before it 'condenses' (the more accurate term is 'precipitate') in the bottom of your tank, which will happen at the 'dew point' of the fuel-water mix.



The best write-up I've seen on this is here:


==============================================



"Diesel can hold water in solution but it doesn't condense out of solution due to gravity, it condenses out due to a drop in temperature, just like water condenses out of air. Diesel #2 holds about 120 parts per million of water at body temperature but can only hold about 40 ppm at 4 degrees Celsius. If you fill up your tank on a warm summer day, even if the diesel is dry, it'll start absorbing water from the air (via the tank vent) until it reaches its saturation point around 120 ppm.

Let that fuel sit in your tank until it gets close to freezing outside and the diesel will be able to hold only about a third of the water it could when warm so the water will condense out as a separate liquid phase. It's only after condensation that it drops to the bottom of the tank due to gravity and the difference in density between water and diesel. The 80 ppm difference between diesel's water saturation at body temp and its saturation close to freezing equates to about 0.3 ml of water per gallon of diesel. If your tank is 100 gallons, you're talking about 30 ml of water, which is about an ounce. If you're on a trawler with 1600 gallons of diesel, you're talking about one beer can worth of water in your tanks.

If the tank were sealed and you brought the temp back up, the water would dissolve back into the fuel. However, the tank is vented so it has access to relatively moist air, which will supply water to the fuel at the same time the water at the bottom of the tank is dissolving back into the fuel, so you'll never get it all back into solution and you'll end up with residual water at the bottom of the tank.

By the same reasoning, you absolutely can get condensation on the tank walls from the water in the air. All it takes is warm, moist air coming in contact with the cold walls of the tank. When that happens, the air will cool near the tank wall, lose its ability to hold as much moisture, and it'll condense out on the surface. This can happen if you're out on a hot, humid day and your tank is colder than the surrounding atmosphere due to its close proximity to cold water on the other side of the hull.

Bottom line, if you can arrange to use all your fuel up without giving it a chance to cycle from warm to cold, you won't get much condensation due to water dropping out of the fuel but you're still vulnerable to water condensing out of the air if you can't keep the tank close to the same temp as the air at all times. In practice, it's virtually impossible to assure both conditions so you just have to live with water in your tanks via good water separators to handle emulsified water, filters that are designed to absorb dissolved water, and biocides that'll kill the bugs that want to grow at the water/fuel interface in the tank.


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Keeping diesel tanks full stops condensation T or F? - Fix It Anarchy - Sailing Anarchy Forums

Greetings,
Mr. X. You're quite welcome. I do have some facility in translating 'Merican to Canadian...
What REALLY burns my biscuits is foyer. It's NOT pronounced the same as lawyer it's pronounced foy-eh. Oh...saloon!

This topic comes up periodically. Here is what I’ve gathered over the years.

- Use a vacuum gauge with a drag needle. If it suddenly jumps up a few mmHg over the normal set point, maybe time to change your filter.

- Racor’s waterblock treatment on their filters will age out. While hard to find, I’ve seen the information from Racor that says that the filters should be changed yearly simply because they become less effective at blocking water.

- I don’t worry about condensation in my tanks. I live in a climate that has cool and very wet winters. I also live in an area that tends to have very clean fuel. I’ve never seen any water in the bowls of my Racors. When I change my filters, they aren’t as black as the OPs, but you can certainly see they are dirty.

- Despite the issue about the water block treatment above, I am currently changing one the two filters in my dual housing each year. I change the filter that was used during the year and then switch to the filter that was changed last year. I used to change both every year but decided that was probably overkill.

The “best” practice would be to change both every year as I did for years on my last three boats. FWIW, never in that time on any of those boats did I ever see a vacuum rise above the 1-3 mmHg present with a new filter. If I didn’t have a dual filter, I would still be changing it yearly regardless.

Ok, we are talking yachts here, or whatever we have that approximates a yacht: as your tank empties it draws in air from the breather. The air has an amount of water in it that may or may not condense out, depending upon temperatures. Your fuel, in your tanks, has pretty much a constant temperature because it is a large volume and it’s sitting in the ocean, which has very little temperature change. If it is possible for ambient air to circulate around the outside of your tank, you will probably get some condensation right after fuelling unless it runs a long way in a hot pipe! Inside the tank, only the water that came with the fuel is in there and if you agitate the fuel, which most of us don’t as we don’t use our boats much, the fuel stays in suspension. The air in the tank will be mostly affected by the temperature of the fuel, which varies little in practice, and so only a small amount of the air goes in or out of the vent, therefore the amount of saturated air being reintroduced is minimal. Ambient air temperature matters little.

The water that arrives from the refinery has enough moisture in it to support bacterial growth but only in perfect conditions for the bacteria, hence the biocides some add to their fuel. I never have had any growth in my location in 15 years and have Never used a biocide.

The answer to the question is technically true but also immaterial to a recreational boater.