Help with Hydraulic filter

benkapitanec · Apr 27, 2009

Fabrication on the new log splitter is on the way. I am currently fabricating a hydraulic reservoir. I'm using 1/4in. steel for the tank. Tank dimensions will equal the output of the pump which is a 28gpm. My question is how important is it to have a suction strainer as well as a return line filter canister set up? I was thinking of just using a return line canister filter rated for the pump size. I hear alot of controversy over suction strainers and the cavitation that may occur while using them. Your suggestions and thoughts on this please.

Wayne County Hose · Apr 27, 2009

Properly designed and maintained, a suction strainer will never hurt a hydraulic system. I have seen big dollar hydraulic equipment with them and without them. The only thing I would be concerned with in your case is initial startup. I would make positively certain there are no foreign objects in your tank, especially welding slag.
IMHO, a 28 gallon tank is a little overkill. I know, a rule of thumb is for the tank to match the pump in gpm, but I have never seen a log splitter that came even close to this. The average splitter is at best 30% of this.
Good luck, Andy.

Scotty370 · Apr 27, 2009

Ben- My home-build is much smaller, the typical 11gpm 2-stage pump w/ a home-built tank made by welding plates on the ends of a 6" pipe, that's only 20" long! That equates to about 2.5 gallons, if it were filled to the brim, with ram full, and fully retracted. So, WCH's "...30% at best.." statement is right on. I've probably got 22%! Point is, I run a suction strainer, and return filter, and have never had a problem. I designed 'seat-of- the-pants' style, ie "Looks good, let's try it"! That's some serious oil flow your pumping, and I assume, that you've factored in the valve, strainer, filter capacities to handle that GPM. .250 plate for a tank? Wow! There's far more superior 'Hydro-Pros' on the board, just wanted to tell of my experience. Might want to wander over to the 'Build-it-yourself' forum, And search "Log Splitter" for a wealth of info. What are you powering with? TPH, or self-powered, trailer mounted? ~Scotty

benkapitanec · Apr 27, 2009

Thanks for your thoughts on this. Seems like all the literature can throw you off some if you don't pick peoples brains some. 20-30% of pump GPM sounds more reasonable. Iwas able to get a 8in. cylinder pretty reasonable. I know it's an over kill tonnage wise but what the ****! If you got it use it.

J_J · Apr 28, 2009

You never said what the stroke is on the 8 in cylinder. How many gal does it hold when fully extended? How large is the engine you plan on using? Have you computed the cycle time for that cylinder. Is that pump a Barnes 2 stage pump? 28 gal of fluid, that is a lot and expensive also.

LD1 · Apr 28, 2009

The 20-30% of gpm is for the two stage pumps only. If you had a single stage 28gpm pump delivering 2500-3000psi, you would want more than 6-8gals. for sure.

But being a 2 stage pump you are only flowing 28gpm up to 650 psi, and then you are only flowing probabally 5-6 gpm. (I couldn't find the exact spec).

However, given the large cylinder, a larger resivor is required.

I crunched some #'s for ya assuming a 24" stroke

Max tonnage at 2500psi..............62
Max Tonnage at 3000psi.............75
Cylinder volume rear...................5.1gal
Cylinder volume front.................4.6gal
Extend time @ 28gpm.................11sec
Retract time @ 28gpm................10sec
Total cycle time.........................21sec
Max tons 1st stage @650psi.........16.3

What does this mean... It means you have a big splitter with a slow cycle time.

But don't let that fool you becase you will still split wood faster because most wood doesnt take 16 tons to split, so you will rarley see second stage. Where as most splitters only make ~4 tons and then kick down to the second stage and go real slooooowwwwww.

So nice work and keep the pics comming.

Scotty370 · Apr 28, 2009

Good points by J_J, and LD1. On J_J's : I just bought 2 gals of JD Low-Vis Hydro at the Green Guys, @ $17.95 ea.! On LD1's "power" numbers, you ought to be able to use a multi-split wedge so your going to be able reduce the total 'cycles-per-cord'! (If there is such a unit of measure!

~Scotty