Log splitter cylinder 2500psi vs 3000psi?

[Slick]

I have a 24" 3000psi welded cylinder on my splitter now, looking to upgrade to a 30". There are a ton of tie rod 2500psi cylinders out there, the 3000psi ones are obviously more expensive but add to that I'd prefer not to get clevis ends (will have to then rework my moving ram also) and the 3K non clevis end cylinders are double what I can get a 2500psi one for.
I currently run my splitter of a small bobat mt50 walk behind skid steer so the 2500psi would actually be fine but at some point I may make a "normal" splitter out of it and use a traditional two stage pump....so the question is 2500 or 3000psi...how much of a difference does it make?


Thanks,

 

[BlueRidgeMark]

I guess it depends on how much safety margin you want. MOST splitters run 2000-2250, I'm told.

 

[John R]

You should be fine with a 2500 lbs, most pumps that you would buy for a log splitter will only build a max pressure of 2200/2500 lbs anyway.

 

[beavis331]

Your pressure is dictated by your pressure relief valve. Most pumps will put out at least 3000lbs. But it is extremely rare to see a hydraulic system that runs that high. Espescially a log splitter. Most run 2000 to 2250 as stated by BlueRidgeMark. As a matter of fact most systems have the relief valve in the control and are set from the factory typically at 2250 psi. Either cylinder will work just fine for your current and future applications. Its just a matter of how much it is worth to you in reworking your clevis mounts.

 

[m37]

I have my pressure set at 2600, at an idle. if i give the motor a little throttle and it puts out 2800. My hoses have a working pressure of 3500. My pump puts out 3000 psi.

 

[kevin j]

As beav stated, fixed displacement pumps (single or two stage are still fixed displacement gear pumps) don't put out 'pressure' they move flow by volume. Pressure is resistance to flow. With heavy load, the pressure climbs until something limits it: wood splits, engine stalls, structure breaks, hose or pump or cylinder splits open, etc. The relief valve bypasses pressure from the pressure line to tank line at some preset number to prevent broken parts. Relief valve will 'crack' at some pressure setting, then have a rise slightly as flow increases, maybe a couple hundred psi usually.

RV is usually located in the manual control valve just due to economy. Most Prince and Energy and other logsplitter valves are screw adjustable. Some industrial valves are shimmed, or sometimes the preset cartridge must be changed. You probasbly have a simple screw adjustment. Many good posts and pics about adjusting that.


A relief valve is ESSENTIAL to any hydraulic system with fixed pumps.

A two stage pump should unload at 700-900, it is not going across relief at that point. nly when it hits the higher 2500-3000 setting does it relieve, and that will be the low flow 2 to 5 gpm.
A single stage pump will relieve all its flow at the RV setting, so the differene between low idle and high idle pressure might rise a bit more..

Force on the splitter is proportional to pressure, so backing the relief down from 3000 to 2500 is a 500/3000 = 1/6 reduction in MAXIMUM force. If the wood only takes 500 oir 2400 to split you will see no difference at all. T'he RV does not affect flow, or 'create' the pressure, it just limits the maximum pressure.

All components have some safety factor built in, of course. Also, thre are NFPA and SAE pressure rating standardized tests for components, usually limited by fatigue after thousands or millions of cycles, but sometimes by seal failures or life. Not nearly as simple as the breaking point of a piece of steel or chain that would be more exact and repeatable

Anyway, I see some choices:
1. Rework the mechanicals to mount the '3000 psi rated' cylinder
2. Run the 2500 psi rated cylinder and figure it can take some overload for some unknown time.
or 3. Reset your relief valve to 2500 and save money, be safe, and probably see very little day to day performance differnce.

Get a gauge in the system. Back the RV out a couple turns, run the cylinder to full extend and stall it, and adjust the RV. Easy job if you have the gauge in place. Searchhere for other posts.


a bit off topic, but if you do the math on most purchased splitters you will see the 22 or 25 or 35 'tons' is often marketing bs, and requires 3200 to 3500 psi to reach those numbers. Most splitters are way less than advertised and they work just fine. A better measure for comparing between brands is simply the cylinder bore size (isnide diameter, not tube OD.).



kcj

 

[Haywire Haywood]

Gotta spread rep around more... Kevin is always very helpful on the hydraulic side of things.

thanks,
Ian

 

[Slick]

Yeah seriously, great post and tons of info, thanks everyone!

Kevins post has me thinking again about my pressure relief...I had a gauge on it but it kept leaking so I took it off...but on the pressure relief...I can't get my return detent to work properly. Running off my bobcat compliates things a bit cause I have pressure relief in there also but right now it returns but doesn't pop the handle out, it just bogs down the bobcat motor like something is dead heading.I haven't played with it since last years so I don't remember what happened when I played with the pressure relief on the splitter valve but it was acting weird I remember...I try it again tonight maybe with some tips on here I can get that working cause it's pain without it!

 

[Swamp Yankee]

This may sound stupid

But then again I guess you need to consider the source.

One of the fastest and easiest ways to troubleshoot a hydraulic issue is to draw a very simple diagram with lines and boxes. I'm not talking about a schematic, but more of a stick drawing. Label each component and hose, be sure to pay attention to sizes as these can be critical.

Once you have this complete two things happen. You are now a lot more familiar with the circuit, and you can start to analyze where there may be issues. Trace the flow just like the splitter was operating and look for areas where restrictions a second relief, or by-passing may occur. In this case heat is your friend. If a component is really hot chances are it's by-passing fluid or in the case of hoses and fittings undersized. (We used to see this a lot in the winch industry, as the builder didn't want to spend the $ for the correct size fittings. Of course the winch wouldn't pull, but that's another story.) In some cases as previosly mentioned you may encounter a secondary or primary circuit with a lower relief setting. Remember hydraulic oil is just like you and me, when given a choice it will always follow the path of least resistance.

Good luck

Take Care

 

[BlueRidgeMark]

a bit off topic, but if you do the math on most purchased splitters you will see the 22 or 25 or 35 'tons' is often marketing bs, and requires 3200 to 3500 psi to reach those numbers. Most splitters are way less than advertised and they work just fine.

I noticed this a few years back, and just last week or two somebody posted the advertised specs for an I&O "32 ton" splitter, that they claimed "most people would call a 40 ton!". Yeah, right. It was a 20. 2000 PSI and a 5" bore. Works out to 19.63 tons. Okay, I have no beef with rounding that to 20, but 32?? That's called, "lying" in my book.


Speeco says they run to 3400 PSI on their 34 ton, so with a 5" bore it's really a 34 ton.

 

[PaulLovesJamie]

As beav stated, ..............

kcj

Good basic info, seeing as I know very little about splitters or hydraulics that helped me quite a bit. Thanks. (rep added )

 

[ZeviB]

Speeco says they run to 3400 PSI on their 34 ton, so with a 5" bore it's really a 34 ton.

Not to be picky, but you need 3,800 psi to get 34 Tons with a 5" bore; similarly, you need the same pressure to get 22 tons with a 4" cyl.

Of course, they may say that they run 3,400 psi at the pump, but if they have a 2,600 psi relief valve on the way, than it's back to the good old BS advertising you were referring to earlier. In fact, I'm looking at buying one of these Huskee babies myself, so I'm curious about that issue also.

Cheers,
Zevi

 

[Haywire Haywood]

Speeco told me that they have the relief valve set to 3500.

Ian

 

[AKKAMAAN]

Not to be picky, but you need 3,800 psi to get 34 Tons with a 5" bore; similarly, you need the same pressure to get 22 tons with a 4" cyl.

Of course, they may say that they run 3,400 psi at the pump, but if they have a 2,600 psi relief valve on the way, than it's back to the good old BS advertising you were referring to earlier. In fact, I'm looking at buying one of these Huskee babies myself, so I'm curious about that issue also.

Cheers,
Zevi

To be real picky....it takes 3463psi to get 34 tons (68000lbs), and 3818psi to make 34 metric tons (74957 lbs).....

 

[ZeviB]

To be real picky....it takes 3463psi to get 34 tons (68000lbs), and 3818psi to make 34 metric tons (74957 lbs).....

Ah, good point. I was thinking tons as in thousand kilograms (metric). Totally forgot about the US short tons. So, if what SpeeCo told Ian is true and they set the valve to 3500 psi, then their 34 (short) tons rating is no advertising BS.

Cheers,
Zevi

 

[Haywire Haywood]

Ha... you were thinking in metric tons and I didn't even know there was a metric ton. I thought "ton" was an imperial measurement.

You originally from the US or are you one of them imports?

Ian

 

[AKKAMAAN]

Ah, good point. I was thinking tons as in thousand kilograms (metric). Totally forgot about the US short tons. So, if what SpeeCo told Ian is true and they set the valve to 3500 psi, then their 34 (short) tons rating is no advertising BS.

Cheers,
Zevi

Thats what they claim.....should be an easy check with a 0-5000psi gauge......what I doubt is that the hydraulic components will hold rating for 3500psi.....most valve, cylinders and pumpsare not rated more than 3000psi.
If you want higher rating than 3000psi, you usually get into a higher $$$ bracket. For example Haldex-Barnes pumps are not rated for more than 3000psi. For a 5" bore cylinder you would think they'd use a high flow pump to get decent cycle time....high flow is 16-28gpm, and for that all recommendation says that at least 3/4" is needed. That will put you on a 4-wire hose.

Until some one check and verify Speeco's PRV pressure setting, and that components are manufactured and approved for 3500psi rating, it is still a sale BS.....

 

[ZeviB]

You originally from the US or are you one of them imports?

A genuine import through and through!
Came here legally from the side of the world that uses sensible units (i.e., metric)...

Cheers,
Zevi

 

[kgreer]

Thats what they claim.....should be an easy check with a 0-5000psi gauge......what I doubt is that the hydraulic components will hold rating for 3500psi.....most valve, cylinders and pumpsare not rated more than 3000psi.
If you want higher rating than 3000psi, you usually get into a higher $$$ bracket. For example Haldex-Barnes pumps are not rated for more than 3000psi. For a 5" bore cylinder you would think they'd use a high flow pump to get decent cycle time....high flow is 16-28gpm, and for that all recommendation says that at least 3/4" is needed. That will put you on a 4-wire hose.

Until some one check and verify Speeco's PRV pressure setting, and that components are manufactured and approved for 3500psi rating, it is still a sale BS.....

pump specs: 3000 psi continuous pressure. 4000 psi intermittent pressure. Pressure is limited by the pressure relief settin in the valve. In our case 3400 psi. in other words, the pump will give you a brief pressure higher than 3000 but will soon drop back down. Usually this amount of pressure is not needed to split a piece of wood.

Kevin@ SpeeCo

 

[2FatGuys]

:welcome:

pump specs: 3000 psi continuous pressure. 4000 psi intermittent pressure. Pressure is limited by the pressure relief settin in the valve. In our case 3400 psi. in other words, the pump will give you a brief pressure higher than 3000 but will soon drop back down. Usually this amount of pressure is not needed to split a piece of wood.

Kevin@ SpeeCo

:welcome: As I have stated before, until someone can show me where ANSI or ASME recognizes safety ratings based on "intermittent pressure", it's all smoke and mirrors. The companies that manufacture the parts don't have those higher ratings, so how can combining the components yield a higher rating. The safety margin expires when the weakest link fails.

Kevin @ Speeco: If oyu want to refute this call of BS, then provide us with copies of the cut-sheets for the components you use. Otherwise, your 5" bore is worth no more than 29.4 tons MAX and your 4" bore is worth no more than 18.8 tons MAX. Please... prove me wrong.