Which way does a filter flow

[woodlandfarms]

OK, kinda stupid, but here is my question, and now I may have my answer in my head but I am moving forward.

When I change hydraulic oil filters, there is at least 2 quarts of oil in them, that I just throw away. I was wondering if I should make some effort to pour it back, and was wondering if I should plug the outside holes or the inside hole to prevent debris from flowing back...

Any thoughts?

Carl

 

[john_bud]

When I change hydraulic oil filters, there is at least 2 quarts of oil in them, that I just throw away. I was wondering if I should make some effort to pour it back, and was wondering if I should plug the outside holes or the inside hole to prevent debris from flowing back...

Any thoughts?

Carl

Just keep doing what you are doing, that's my thought.

jb

 

[woodlandfarms]

Let me try this again, maybe in english this time.

I would love to save the oil out of my filter. It must be 2 quarts at least. But, does oil flow from the outside of the filter to the inside, or the other way around? I have assumed it was from the outside ring to the inside.

And is there a way to collect this oil without re-introducing debris into the system?

Or, am I as usual, overthinking it and I should just put the 2 quarts on my burn pile and call it good?

 

[RickB]

Let me try this again, maybe in english this time.



And is there a way to collect this oil without re-introducing debris into the system?

Or, am I as usual, overthinking it and I should just put the 2 quarts on my burn pile and call it good?

Typically, oil flow is from the outside to the inside of the media.
There is no practical way of "saving" the contained oil without "saving" the trapped contaminants.

Call it good.

 

[Wayne County Hose]

Carl, you're over thinking it. You're not back to work yet?

 

[Reg]

Just casually looking at a filter cylinder you would think that outside to inside would expose the greatest surface area to flowing oil and therefore be "better".
Well, kinda/sorta - filters are pleated.
So if you think it through again, the Vee's of the pleats are more opened on the outside, so still "better" flow, more area, slower blocking from out to in.

{Yeah, overthunkin'}

Now, if you REALLY want to recover the oil that is in the filter and want it to go through the filter first...
Don't worry about any of this, just block the "In" and pour it out of the "Out",
but with a spin-on filter that would be tricky because the "In" is a ring of holes.
Probably not worth the expense and time to fab up a filter head, etc.

 

[SnowRidge]

For the PT's main hydraulic filter only, any crud should be trapped in the filter medium. You could pour the filter full of oil back into the hydraulic tank. If you did not introduce any extraneous contaminants (big if) by the act of removing the tank cap and setting up a funnel, you should be no worse off than if you pitched the oil. After all, it just came out of the very same tank.

I still wouln't do it.

 

[SPYDERLK]

OK, kinda stupid, but here is my question, and now I may have my answer in my head but I am moving forward.

When I change hydraulic oil filters, there is at least 2 quarts of oil in them, that I just throw away. I was wondering if I should make some effort to pour it back, and was wondering if I should plug the outside holes or the inside hole to prevent debris from flowing back...

Any thoughts?

Carl

The oil in there is as clean as that being pumped to the filter. The accumulated debris is in the filter media. Clean off the outside of the filter case and then punch a hole in the edge of the end of the can and let drain into a clean container.
larry

 

[BotaBigot]

While I personally wouldn't do it, I can understand your wanting to save the 2 quarts. The safest way would be to siphon it thru the center hole...

 

[woodlandfarms]

Carl, you're over thinking it. You're not back to work yet?

Oh you betcha. Friggin actors. I am pro-union, but the writing is on the wall. Either cut back on your paycheck or watch the jobs disappear. Actors are just shooting themselves (and the rest of hollywood) in the foot. I respect their demands, but now is really not the time.

Expect more reality TV guys.

 

[BotaBigot]

...Expect more reality TV guys.

That'll work. Less time in front of the tube, more time fiddling with my tractor and cars and maybe even...reading...

 

[kthompson]

That'll work. Less time in front of the tube, more time fiddling with my tractor and cars and maybe even...reading...

And life will be improved!

 

[Wayne County Hose]

He-he. I kinda figured that if you asked a question like that, the actors were still on strike and you're not working and have a lot of time on your hands.

If you remove your filter and pour the oil into a clean pan, you will see a lot of little specs of debris. Now, imagine all the little ones you can't see. It's not worth the 2 quarts of oil to take the risk.

 

[RickB]

The oil in there is as clean as that being pumped to the filter. The accumulated debris is in the filter media. Clean off the outside of the filter case and then punch a hole in the edge of the end of the can and let drain into a clean container.
larry

The oil on the 'dirty' side of the filter is not as clean as that entering the pump because it hasn't been filtered yet. In fact, it is probably the dirtiest oil in the entire machine. The media will trap the debris until flow stops, then a significant amount of debris migrates away from the media and disperses into the unfiltered oil. That's why a machine with a plugged hydraulic filter often has some flow at startup inspite of having cold, thick oil. As flow drives the debris back into the media, it becomes plugged all over again. When considering filter volume, there is more dirth oil outside the media than there is clean oil within it.

Remove the filter and discard it and the oil it contains. It is penny wise and pound foolish to do otherwise.

 

[john_bud]

Now if you get a flamable liquid pump, a filter head, an extra filter and a large tank then plumb it up so it will recycle the oil, you can filter out the impurities. But will still have the water. So you will need to set up a distillation column to get the water out. Will need to be stainless and have pressure reliefs so it won't blow up, etc. Then the additive package has to be renewed, but you will want to know how much of each to add, so you will need an analysis done. I figure you can get all that in place for just about $2000. Oil analysis will be about 20 bucks plus postage for each go round.

How much oil are you wanting to save and what return on investment are you looking to get?

 

[SPYDERLK]

The oil on the 'dirty' side of the filter is not as clean as that entering the pump because it hasn't been filtered yet. In fact, it is probably the dirtiest oil in the entire machine. The media will trap the debris until flow stops, then a significant amount of debris migrates away from the media and disperses into the unfiltered oil. That's why a machine with a plugged hydraulic filter often has some flow at startup inspite of having cold, thick oil. As flow drives the debris back into the media, it becomes plugged all over again. When considering filter volume, there is more dirth oil outside the media than there is clean oil within it.

Remove the filter and discard it and the oil it contains. It is penny wise and pound foolish to do otherwise.

The oil being pumped to the filter is exactly as clean as the oil in the filter on the pre filtered side, as I said. The oil goes thru a filter thousands of times. If the filter were routinely filtering out much it would fill up and bypass or else block the system within a very short time. So the difference between the oil on the 2 sides of the filter media quickly reaches a near zero value after any event that dirties the oil with particulate. Or else the system fails, giving a clue.

That migration back into the oil when flow stops is extremely small. The effect of full filter system blockage you describe is due to the pleats closing up in the filter under constant high suction, and then reopening when idle for awhile.
larry

 

[RickB]

The oil being pumped to the filter is exactly as clean as the oil in the filter on the pre filtered side, as I said.

If that were true, there would be no need for filters of any kind. You really need to think about that.

The oil goes thru a filter thousands of times. If the filter were routinely filtering out much it would fill up and bypass or else block the system within a very short time. So the difference between the oil on the 2 sides of the filter media quickly reaches a near zero value after any event that dirties the oil with particulate. Or else the system fails, giving a clue.

That migration back into the oil when flow stops is extremely small. The effect of full filter system blockage you describe is due to the pleats closing up in the filter under constant high suction, and then reopening when idle for awhile.
larry

We disagree.
It is a safe bet I will NEVER drain a spin on filter and pour the contents back into whatever system the filter is protecting.

 

[SPYDERLK]

If that were true, there would be no need for filters of any kind. You really need to think about that.

Thats laughable. Check your reading comprehension.

 

[RickB]

Thats laughable. Check your reading comprehension.

I did. Now you go pour out a used hydraulic filter. The notion that ALL contaminants are permanently affixed to filtering media is naive, and that's being charitable.

Get over the fact that we disagree on this. It happens.

 

[SPYDERLK]

I did. Now you go pour out a used hydraulic filter. [[The notion that ALL contaminants are permanently affixed to filtering media is naive]], and that's being charitable.

I have, but I didnt shake it up 1st. [[Sure is - and I didnt say it]]