Gravity-purification in your hydraulic tank (or perhaps better,... on the shelf)

[Sodo]

Why wouldn't you stick a whole bunch of neodymium magnets on the bottom of the hydraulic oil tank next time the lid's off?

All the steel goes down by gravity when it's still.
If eqpt gets parked for a month I'll bet the steel drops to the bottom 100%.
Now if there's a way to get it to stay there, and not circulate, it's better for the machine.

Magnets will probably hold the steel at the bottom.
A plastic mesh like a pot-scrubbie above the magnets would create a "still area" in the vicinity of the magnets.
The mesh could be cut in the shape of the hydraulic tank where it steadies itself against the tank walls and prevents sloshing below it.

It seems like a real simple method to reduce the steel circulating in the oil.
Stone might settle to the bottom too, but the magnets wouldn't hold stone.
But if the stone settled down into the mesh, it might remain there, and not circulate as much.

 

[Portuguese Farmer]

Why wouldn't you stick a whole bunch of neodymium magnets on the bottom of the hydraulic oil tank next time the lid's off?

All the steel goes down by gravity when it's still.
If eqpt gets parked for a month I'll bet the steel drops to the bottom 100%.
Now if there's a way to get it to stay there, and not circulate, it's better for the machine.

Magnets will probably hold the steel at the bottom.
A plastic mesh like a pot-scrubbie above the magnets would create a "still area" in the vicinity of the magnets.
The mesh could be cut in the shape of the hydraulic tank where it steadies itself against the tank walls and prevents sloshing below it.

It seems like a real simple method to reduce the steel circulating in the oil.
Stone might settle to the bottom too, but the magnets wouldn't hold stone.
But if the stone settled down into the mesh, it might remain there, and not circulate as much.

Magnetic drain plug

 

[thclimer]

I'm only guessing if there is that much "steel" in your hydraulic system you have bigger problems that need to be addressed or will be evident by operational problems. If there is a small amount I would think the filter would catch it preventing it from getting to critical parts like your pump.

 

[oldnslo]

Companies make magnet trees for use in reservoirs mostly designed for industrial use pumps and motors that have case drains that typically cannot be run through a return line filter. Like thclimbrr states a good return line filter is a better defense in keeping the reservoir clean on most systems especially mobile equipment since there reservoir volume is usually very low compared to pump volume.

 

[bdhsfz6]

Not a bad idea but many of those particles are stainless steel & brass which a magnet won't pick up.

 

[Sodo]

The thing is..... hydraulic filtration goes down to 10 microns "at best".
Oil film thickness can be 1/2 micron when a pump is "working hard".

So particles between ----> ~2 and 10 microns are flowing freely, getting mashed between your precision surfaces.
So there's a lot of steel dust that you cannot filter out, you just live with it.
There is a "normal component lifetime" associated with "normal levels of lubricant contamination".

If you can reduce contamination, longer component lifetime can be expected.
One way is to replace the hydraulic oil at shorter intervals.

=============================
It's cool when magnets catch and hold larger particles.

But on on very tiny particles, magnetic attraction is very weak. Like the fine dust on a magnet, it's just "barely held" by a magnet.
The magnets don't draw fine steel dust out of the oil. But they can "hold it" if it drops down onto the magnet by gravity (when the oil is "still").

That's why you'd want lots of magnets spread around rather than just one drainplug.

You want to catch and hold any very-hard steel wear-particles for sure.
Brass & aluminum can be considered a "cushion" - they are the best kind of dust to have.

Stone is bad though. Water is bad.

The concept of catching & holding oil contaminants "out of the flow" in a non-moving area on the bottom of the reservoir seems reasonable to get longer life from valve bodies and pumps.

Then the bulk of the hours, the machine is operating with the upper stratification (the more purified) oil.

The gravity method seems "real easy" too (good for the lazy person !!)

 

[Sodo]

Here's another way.
I think I like this way better.
It's straightforward and you can see the benefit.

If you put eqpt away for a few months in the winter, run the machine, get it warmed up, then drain the Hydr. oil reservoir.

In the spring all the metal and stone will be at the bottom of your pail.
You will see the layer. Pour the clear oil back in, being careful to stop, leaving the sediment behind. You're not purifying all of the oil, just the portion that's in the reservoir.

If you take the lid off and look at the oil, you'll know when it becomes clean again. It gets significantly clean in a month, and clear as honey in 2 months. It's useful to set the pail purifying at an angle so you can get more clear oil out without disturbing the sediment.

 

[rScotty]

Why wouldn't you stick a whole bunch of neodymium magnets on the bottom of the hydraulic oil tank next time the lid's off?

All the steel goes down by gravity when it's still.
If eqpt gets parked for a month I'll bet the steel drops to the bottom 100%.
Now if there's a way to get it to stay there, and not circulate, it's better for the machine.

Magnets will probably hold the steel at the bottom.
A plastic mesh like a pot-scrubbie above the magnets would create a "still area" in the vicinity of the magnets.
The mesh could be cut in the shape of the hydraulic tank where it steadies itself against the tank walls and prevents sloshing below it.

It seems like a real simple method to reduce the steel circulating in the oil.
Stone might settle to the bottom too, but the magnets wouldn't hold stone.
But if the stone settled down into the mesh, it might remain there, and not circulate as much.

You are right that filtration by settling is the very best type of filtration. It is widely used for removing things from solution that are too small for filters with pores to handle. Great for separating fine particles held in solution for everything from dyes to pharmaceuticals. Handy for analytics, too, since settlement mateiral naturally stratifies as it settles.
Centrifuging anything is the same as natural settlement, just faster.

The brewing industry uses natural settlement in vats and the siphoning to remove yeast from beer before bottling.

Downside to magnets used as you describe is that trapped ferromagnetic particles line up to follow the magnetic field which "short circuits" the magnetic field and makes its effect less far reaching. An old trick to get around that and also get rid of ferromagnetic particles is to put your neo magnets onto the outside of the disposable filter cannister. - which is made of thin steel. Win/win.

Another way to use pore filtration is to direct part of the flow through a by-pass fllter with a very small pore size. Hi performance pumps and engines often direct a few percent of the flow through a sub-micron filter. Over time, that really makes a difference.
Bypass filters have been around for 100 years. Was popular with planes in WWII. And with cars in the 1950s. There is no downside to them. You can buy a complete bypass filtration kit on Amazon for very reasonable.

Which reminds me that Kubotas with the "HSTplus" transmission have an additional replaceable bypass filter for superfiltration. That system not only super filters the HST oil 100%, over time it does the same for all the trans/hydraulic oil. That filter is specially built and about $75 to replace - maybe the high price is because sub 2 micron media is special, and also the filter body is a pressure type rather than a suction fllter.
Just me rambling,
rScotty

 

[ZiggyD]

Here's another way.
I think I like this way better.
It's straightforward and you can see the benefit.

If you put eqpt away for a few months in the winter, run the machine, get it warmed up, then drain the Hydr. oil reservoir.

In the spring all the metal and stone will be at the bottom of your pail.
You will see the layer. Pour the clear oil back in, being careful to stop, leaving the sediment behind. You're not purifying all of the oil, just the portion that's in the reservoir.

If you take the lid off and look at the oil, you'll know when it becomes clean again. It gets significantly clean in a month, and clear as honey in 2 months. It's useful to set the pail purifying at an angle so you can get more clear oil out without disturbing the sediment.

My dealer recommended doing something similar instead of replacing all the hydraulic fluid. Essentially replace the filter at the appropriate intervals, drain a quart or two and refill accordingly. They said the it didn’t make sense to replace all 12 gallons of fluid and to save my money

 

[rScotty]

Here's another way.
I think I like this way better.
It's straightforward and you can see the benefit.

If you put eqpt away for a few months in the winter, run the machine, get it warmed up, then drain the Hydr. oil reservoir.

In the spring all the metal and stone will be at the bottom of your pail.
You will see the layer. Pour the clear oil back in, being careful to stop, leaving the sediment behind. You're not purifying all of the oil, just the portion that's in the reservoir.

If you take the lid off and look at the oil, you'll know when it becomes clean again. It gets significantly clean in a month, and clear as honey in 2 months. It's useful to set the pail purifying at an angle so you can get more clear oil out without disturbing the sediment.

Gravity purification was once a common industrial process. Much cheaper than a centrifuge for large samples. I remember one text book even had typical equations for time vs materials and liquids - now long forgotten.
The process was ancient & sometimes used to purify a liquid, but usually for collecting and concentrating precipitates.
The standard way to remove the liquid is to use a siphon rather than pour. Much better results.

 

[Too many Kubotas]

An old trick to get around that and also get rid of ferromagnetic particles is to put your neo magnets onto the outside of the disposable filter cannister. - which is made of thin steel. Win/win.
rScotty

I've used those external magnet setups for years.

Why do I believe in using magnets? Because if filters really worked well I'd never find anything on the magnetic drain and level plugs. But I always do.

 

[Sodo]

if filters really worked well I'd never find anything on the magnetic drain and level plugs. But I always do.

Filters are limited to about 10 microns. Oil film of hydr oil (AW46 20w?) could be less than 1/2 micron. So particles that affect the life of your machine smaller than 10 microns go right thru the filter. A magnet will catch some of them and that's a good thing. Keep in mind the magnet does not reach across the reservoir and draw steel. Nor does it pull (tiny) steel out of moving fluid. The black dust you see is what falls onto the magnet (by gravity) when the oil is still. It's a small "purification cone".

===========

I think a good way is to have some spare Hydr oil on hand, You suck out some oil that has been there awhile and set it on a shelf. Perhaps in a water-clear gallon bottle so you can see when it becomes clear as honey. Let the metal & stone settle to the bottom (on the shelf).

Then when you have a few minutes, you just suck out a used gallon, and pour in a clean gallon. Or 2gal, or 5 gal.
Like an "exchange". But you have to label your oil jugs and stuff. It takes a little bit of organization but it could pay for itself in oil savings, and keeping a clean machine. Here, 5 gal is ~$90 with tax. The best way is to have different shelves for "settling" and "purified".

The oil you sucked out goes on the shelf, self-purifying for the next round. It's not a lot of effort, just takes organization.

I don't know how many rounds you can purify oil, topping up with some fresh oil as needed. Probably 3 or 4 times is reasonable.

The standard way to remove the liquid is to use a siphon rather than pour. Much better results.

[YouTube]

I will do it like this. In the past I used the shop-vac but the 18v blower is easier to carry out to the machine. This blower was about $60 and uses my Makita batteries.

 

[jigs_n_fixtures]

Last I read, is that magnets actually cause the really fine metal particles, the ones too small for the filter to catch, to spin like little motors, and stay in suspension. This would idicate that magnets are actually a bad idea.

 

[rScotty]

I've used those external magnet setups for years.

Why do I believe in using magnets? Because if filters really worked well I'd never find anything on the magnetic drain and level plugs. But I always do.

Maybe so, though it makes me wonder....It depends on where the magnets are. Either pre or post filtered oil.

Hydraulic system standard suction type filters are limited to about 10 microns when new in order to have a large enough pore size to keep the flow rate up. Pressure and bypass type filters can filter as small as wanted. They start at about 4 microns and go down to tiny fraction of a micron depending on the media chosen. .... but the flow rate goes down unless the filter is very large.

Any home mechanic can easily add bypass filtration to an engine or trans/hydraulic system.
Amsoil and Frantz offer bypass kits and sell the special filters.

BTW, some tractors already have bypass super filtration for the HST.

 

[Sodo]

Last I read, is that magnets actually cause the really fine metal particles, the ones too small for the filter to catch, to spin like little motors, and stay in suspension. This would idicate that magnets are actually a bad idea.

That doesn't sound feasible. I highly doubt a magnet has any effect on a tiny particle until it's within a few mm.
I'd be interested to read the article though, if you can remember where you saw it or a link.

=================
Pre-filter is interesting if the magnetic filter is "inspectable" it tells you if something is generating "steel". In that case the filter would take longer to plug up too.

However, note that as a filter plugs up it filters "finer".
Unless it goes into "bypass".
If the filter catches it.....and is able to hold onto it.... that's good for the machine.

super-bypass filtration - that is on-going and does not require effort to extract, label & manage jugs of oil.....
is a better method.
Especially if you have several items of hydraulic eqpt.

 

[m5040]

I'm only guessing if there is that much "steel" in your hydraulic system you have bigger problems that need to be addressed or will be evident by operational problems. If there is a small amount I would think the filter would catch it preventing it from getting to critical parts like your pump

ANY steel is not good. Before you disregard the idea, hang a good magnet in the hyd tank (it doesn't have to be at the bottom, the flow will bring steel to it) and check it after 50 hours. If when you wipe it off on a paper towel, it doesn't leave a black residue, you have a fantastic filter/machine.

 

[Lavender Valley]

The thing is..... hydraulic filtration goes down to 10 microns "at best".
Oil film thickness can be 1/2 micron when a pump is "working hard".

So particles between ----> ~2 and 10 microns are flowing freely, getting mashed between your precision surfaces.
So there's a lot of steel dust that you cannot filter out, you just live with it.
There is a "normal component lifetime" associated with "normal levels of lubricant contamination".

If you can reduce contamination, longer component lifetime can be expected.
One way is to replace the hydraulic oil at shorter intervals.

=============================
It's cool when magnets catch and hold larger particles.

But on on very tiny particles, magnetic attraction is very weak. Like the fine dust on a magnet, it's just "barely held" by a magnet.
The magnets don't draw fine steel dust out of the oil. But they can "hold it" if it drops down onto the magnet by gravity (when the oil is "still").

That's why you'd want lots of magnets spread around rather than just one drainplug.

You want to catch and hold any very-hard steel wear-particles for sure.
Brass & aluminum can be considered a "cushion" - they are the best kind of dust to have.

Stone is bad though. Water is bad.

The concept of catching & holding oil contaminants "out of the flow" in a non-moving area on the bottom of the reservoir seems reasonable to get longer life from valve bodies and pumps.

Then the bulk of the hours, the machine is operating with the upper stratification (the more purified) oil.

The gravity method seems "real easy" too (good for the lazy person !!)

Years ago, I was opening a Quarry, and people objected by putting Ajax, an abrasive cleaner, into the big excavator hydraulic tank (200 gals). That went through the system, pealing and hardening off pump gears. The same was true for hydraulic motors and rams. Then, all the bits were found in the filters. Hydraulic oil is filtered when returning to the tank, too late. Most drain plugs are magnetised, as this one was, again, too late.

 

[Dennis Mohn]

Was this posted on April 1? If you have so much dirt and metal in your hyd tank you need to either start practicing better housecleaning or find the reason your system is accumulating trash.

 

[Sodo]

Was this posted on April 1? If you have so much dirt and metal in your hyd tank you need to either start practicing better housecleaning or find the reason your system is accumulating trash.

April fools? Perhaps you misunderstand...... this is an entirely different subject.
Other posters mentioned "so much metal and dirt etc"

This effort is to remove the “normal” steel and "normal" stone that the “normal” system filter cannot catch & hold. Its like replacing the hydraulic fluid more often without spending more $$ on oil.
5 gallon pails are about $85 now.

You put a little effort in,
save some oil $$
your cleaner oil reduces wear,
your machine lasts longer.

If you feel your MFR's maintenance intervals produce a sufficient lifetime,
your extra effort may just amount to "a favor" for the the next owner (after you sell it).

 

[nyone]

Anything you can get out of the fluid will help. If theres low of metal in your hydraulics you may have other issues. For filters typicaly the tank is the dirty side of the filter and the filter is the suction side..the side you really care about and need to be clean.

Then theres the problem of additives that can wear out, thus the hourly cycle of changing out hydraulic fluid. Typicaly 600-1000hrs. And that's going to be way cheaper than alot of components in the hydraulic system.