Do you recommend a hydraulic fluid filter or strainer on a log splitter?

[Lab-lover]

I have an older 5hp, 11 GPM, 3" x 24" cylinder, hydraulic log splitter which goes by the name of Abe's Baby. A couple of months ago it sucked a chunk of metal from someplace into the pump and damaged the gears. I have ordered a new 11 GPM pump but to avoid a repeat I would like to install a strainer or filter on the suction side of the pump. All of the hoses are currently attached with 1/2 inch threaded fittings.

Does anyone have a recommendation of which would be better, strainer or filter? Also, I assume I can switch to clamped hoses on the suction side if I install a filter or external strainer?

Thanks in advance for any info.

 

[D&B Mack]

Filter... by using a strainer, you would just be kicking the can down the proverbial road.

 

[Lab-lover]

Thanks for the response.

So I would just have to find a filter mounting plate and a filter which will allow at least 11GPM flow? Would you recommend looking for 11GPM flow specifically or should I go for a higher flow rate? Do you have any suppliers that you would recommend?

 

[D&B Mack]

Thanks for the response.

So I would just have to find a filter mounting plate and a filter which will allow at least 11GPM flow? Would you recommend looking for 11GPM flow specifically or should I go for a higher flow rate? Do you have any suppliers that you would recommend?

For something that cheap, I would size up. Northern tool should have what you need.

 

[wndwlkr]

you should have a strainer on the suction side for sure. if you put a filter on also put it on the return side.

 

[kevin j]

NO filter on suction side. Strainer if you choose to, but go twice the size that Northern recommmends.

Put the filter on the return line. Go oversize here also, quite cheap.
Do you mean the suction side has 1/2 inch hoses also? Way too small for suction side.

Suction hoses have a spiral wire in the layers to prevent collapse under vaccum. A hose capable of 3000 psi pressure outward can collapse under suction with cold oil.

 

[Lab-lover]

Yes all hoses on this splitter are threaded 1/2 inch NPT, including the suction side and pump inlet. I might be able to bore and thread a larger hole into the reservoir, what size should the suction side be for a 5hp, 11GPM system?

Since I am trying to protect the pump from pulling in debris which might harm the gears why not put the filter between the reservoir and the pump? With the filter placed on the suction side I would stop any parts which happen to fall / break off the valve and cylinder and make their way to the reservoir from getting into the pump.

You are suggesting that I put the filter in the return line between the valve and the reservoir after the fluid has gone thru all of the critical components? Seems like the protection would be too late at that point. How much pressure would there be on the return line?

Thanks

 

[brenndatomu]

Correct, no filter on suction side unless you want to find out what your filter looks like after the guts are sucked through your pump on some cold Saturday morning. That is the main issue with putting a filter on the suction side, starving the pump for oil. Even if you can get it to work in normal temps., it probably would cause you problems in cooler weather. If you look at heavy equipment hydraulic systems, they never (or VERY rarely) have anything besides maybe a screen on suction side, that's just how it's done. An oversized filter on the return side is your best bet. Any good hydraulic supply house can tell you what you need. Oh, and there should be very little pressure on the filter in the return line, as this should be a open ended line back into the tank. Your filter would cause a small amount of back pressure but not much. (like 10-20 psi, at most)

 

[Lab-lover]

OK, that makes sense even to me.

However, since my first pump already sucked up something which must have come from the reservoir I am concerned that it might contain other debris. I have drained the hydralic fluid out of it, filtered it and intend to pour it back thru the reservoir a few more times to try and flush out any other crud which may have built up over the years. I have also used a magnet to pick up what I could from the various ports. But I would still like to put a screen / strainer someplace in the suction line to protect the pump. Do you have a recommendation for a strainer which wouldn't cause the pump to starve on a cold day?

 

[brenndatomu]

Yeah, you will want to clean up your reservoir for sure. Most strainers are built into the tank. I'm not sure if anybody makes an easily installed "in line" screen on not. Maybe someone else will know about that, again I'd call a hydraulic supply house. I have seen a couple suggestions from others on here about who they like to work with for hyd. parts. I just don't remember any names right now. Try looking up the "catersplitter build" thread from a few weeks ago, I think he had a good suggestion for someone to work with on hyd. problems/parts.

 

[Lab-lover]

I would like to install a screw-in type strainer screen in the reservoir for a couple of reasons; 1) to protect the screen from getting bumped, 2) to reduce the number of external connections and possible leak points. Since my reservoir is only 2.5 inches deep my strainer would have to be 2.25 inches long and fit thru a 1/2 inch NPT threaded hole.

I will wait until someone answers my question about how big of a hole I should bore into the reservoir to avoid starving my 11GPM pump before I order anything new.

 

[wndwlkr]

11 gpm pumps that i'm looking at all have 1" hose barb on the suction side.1/2 " there will starve the pump. you'll problaby need 1" from the tank to the pump. the strainer i have on mine threads into a 2" fitting in the tank. any pics you might have would help alot !

 

[ray benson]

If the oil tank is clean and the return line 10 micron filter is piped to the tank - then all oil is filtered that goes back to the tank. Inlet filter is not required since the hydraulic oil will not contain particles large enough to be captured by the coarser mesh strainer.

Hydraulic Filter, Hydraulic Filters

Inlet filters increase the chances of cavitation occurring in the intake line and subsequent damage to, and failure of the pump.

 

[kyle1!]

Mfg use strainers

Someday I'll get on my log splitter project but the oil tank I bought to use came off a piece of vermeer industrial equipment. It contains 1 intake and 2 suction ports both with strainers. I assume each suction port goes to a different pump and they are using clean parts for equipment assembly why would they use a strainer if it is bad to do so?

Brian

 

[JHctRednek]

The operation of a hydraulic pump on the suction side is very different than the output side of the pump. Most gear type possitive displacement hydraulic pumps can only pull 5 to 6 inches of Hg therefore line losses in the suction side must be watched closely. Good design practice is to maintain hydraulic fluid velocity below 4 feet per second on the suction side of a hydraulic pump.

To answer your question on the sized hole required for 11gpm flow at 4fps is 1.06"

Suction strainers are important to a system bacuase they catch the "incidentals" IE dirt from filling, rag threads, debri etc. They should be installed above the bottom of the tank to ensure the pump does not injest water. One very simple strainer is a pipe cut at a 45* angle with a 100 mesh screen brazed over the end.

One more thing to consider, your return filter should not be designed for 11gpm only! There are different return flow rates when the cylinder is retracting vs extending because of the different volumes of the rod side vs blind side of the cylinder. For return filters the bigger the better!!!

If you would like to investigate hydraulics further this webpage is a good source Hydraulics and Pneumatics Home Page just go to fluid power basics

If you want to learn more about filters hydac HYDAC Literature has a pretty good discussion in the first 10 pgs

Best of luck

PS: Use both a strainer and a return filter

 

[brenndatomu]

Someday I'll get on my log splitter project but the oil tank I bought to use came off a piece of vermeer industrial equipment. It contains 1 intake and 2 suction ports both with strainers. I assume each suction port goes to a different pump and they are using clean parts for equipment assembly why would they use a strainer if it is bad to do so?

Brian

A strainer, or screen on the suction side is good, a full blown filter is a bad idea. A filter is good on the return side. JHctRednek nailed it.

 

[Lab-lover]

I will try to add a picture of the splitter this weekend but for now I can give some dimensions. The reservoir is 3" x 3" x 58", after taking away the 1/4" walls I have an interior tank of 2.5" x 2.5" x 57.5" = 359.4 cubic inches or 1.56 gallons of hydraulic fluid.

The problem I am going to have installing an in-tank strainer is that the reservoir doubles as the beam the log rests on when being split. With only 2.5" of clear depth I obviously can't install a long strainer and only 2.5" of open side wall I can't install a large diameter strainer. So maybe the answer is as JHctRednek suggested, brazing a relatively fine mesh screen onto the angled end of a pipe nipple. That way I can make it to fit my reservoir after I bore and thread a larger hole to allow more flow. I'm also planning on installing at least a 20 GPM filter on the return.

Thanks for all of the advice everyone and please keep it coming. Once I post a photo of the splitter you might have lots more suggestions.

 

[half]

oil capacity

1.5 us gallons seems a bit small to supply the splitter, there does not seem to be enough oil for cooling or the difference in oil requirements for the ram i.e. when it is extended it needs more oil, due to the larger area on the back of the piston. I would think 5 US gallons would be the start amount, and go up from there. Mine holds about 8 US gallons,and it is a 22ton champion, the more oil the cooler they run.
Suction hoses need to be at least double the return size. if the return is 1/2in use 1in on the suction side So you have no chance of cavitation in the pump. and a good spin on return filter is a must, but mount it up near the control bank so when you go to change it you will not have problems with oil running everywhere, and if possible mounted flat,so the oil stays in the filter,when you unspin it.and the rubbish stays in the filter.
There is nothing worse then trying to change a filter and oil running out because it is mounted too low.
Never use thread tape on hydraulics you can bet it will go through the system at some stage and cause problems, I always use locktite hydraulic paste on all threads except hose ends,.
To stop oil foaming and help protect the pump always have the return piped under the oil in the tank.

 

[JHctRednek]

The problem I am going to have installing an in-tank strainer is that the reservoir doubles as the beam the log rests on when being split. With only 2.5" of clear depth I obviously can't install a long strainer and only 2.5" of open side wall I can't install a large diameter strainer. So maybe the answer is as JHctRednek suggested, brazing a relatively fine mesh screen onto the angled end of a pipe nipple. That way I can make it to fit my reservoir after I bore and thread a larger hole to allow more flow. I'm also planning on installing at least a 20 GPM filter on the return.

If you can give me the dimensions of the cylinder I can verify for ya that 20 gpm is gonna be enough. I would need rod dia, bore dia and stroke.

Half also has a good point about the oil capacity and return location. In an ideal world you like to see 1.5 to 2 times the pump output for reservoir capacity for cooling and oil dwell time to help with particulate settling and removal of air entrainment in the oil. As I said this is in an "ideal" world. I would recommend at least as close to 11 gal as you can get it.
Could you combine the axle assembly with the beam assembly to get more capacity? you know two pieces of box tubing in a "T"?

If you want a really slick splitter install this circuit:

View attachment 254615

Sorry I still am not good at posting pics,

The circuit is a regenerative circuit, it allows for faster extension when there is a low load on the cylinder. Like when you are getting to the log and when there are just little stringers you are finishing up in the split, but full power when the splitter needs it.

Best of luck

 

[mga]

a strainer, although maybe a some what good idea, would also be a pain in the ass to clean or change. being on the suction side, that means you have to drain all the oil to replace or clean it.

a good filter on your return line is all you need. once the oil cycles a couple of time, there should be no debris in the oil. unless you're dumping dirt and stones into your tank, you don't need a strainer.

been running mine since 2006 and my oil is still perfect and never had an issue.