Hydraulic Tank TOO small?

[WoodTick007]

I have modified a splitter that I purchased used....It started out 5.5hp and 11gpm pump with a 2.5 gallon tank....I changed out the engine and pump to an 11hp and 16gpm pump. My cylinder is 1.25" x 26". Is my tank too small? Is so could I attach a 2.5-5 gallon steel can (Biltz gas can) in the return line to increase the size?


I am having no problems with the spitter operating properly....

Thanks
G

 

[jags]

With that small of a diameter ram I would think that you are OK with your tank volume. The only thing to watch for is to make sure your fluid doesn't get HOT. It will naturally warm up with use, just make sure it stays cool enough to hold your hand on the tank (comfortably).

 

[jags]

Heat is not the only problem. A properly sized hyd. tank gives air bubbles time to rise out of the return fluid and not be drawn back into the pump. Air bubbles in a pump cause cavitation and can quickly eat up a pump.

Your tank is too small.

Treeco had a VERY valid point with the air bubbles. However, if your splitter is not having any cavitation problems (you would hear the pump whine and pulse), you may be able to get away with it. NOTE: "may be able to get away with it" does not really mean it is the right thing to do. If you have an option of a larger tank, go for it.

 

[ray benson]

I have modified a splitter that I purchased used....It started out 5.5hp and 11gpm pump with a 2.5 gallon tank....I changed out the engine and pump to an 11hp and 16gpm pump. My cylinder is 1.25" x 26". Is my tank too small? Is so could I attach a 2.5-5 gallon steel can (Biltz gas can) in the return line to increase the size?


I am having no problems with the spitter operating properly....

Thanks
G

Hope you meant your cylinder rod was 1.25" dia. Otherwise your cycle time would be about 1/2 second each direction.
A ballpark rule of thumb on tank sizes for splitters is 1 gallon of tank capacity for each gpm the pump puts out. So a tank for you should be about 16 gallons. Smaller tank sizes will reduce how long you could run the splitter before the oil gets too hot( about 150° ).

 

[asb151]

A ballpark rule of thumb on tank sizes for splitters is 1 gallon of tank capacity for each gpm the pump puts out. So a tank for you should be about 16 gallons. Smaller tank sizes will reduce how long you could run the splitter before the oil gets too hot( about 150° ).

Agreed. Not to mention lower average oil temperatures over time mean longer life for seals and gaskets.

My Iron & Oak has ~10 gallon tank. One of the many reasons I choose it over some of the cheaper models with 2-3 gallon tanks.

 

[treesurgeon]

splitter hydrolic fluid f-ing hot.

i have an american cls splitter. it has a small tank. dont know the size because its not listed anywhere. it gets so hot that you cant touch the tank if you have been splitting for a couple of hours. is this normal or just a bad design? what can i expect could go wrong with it running this hot?

 

[treesurgeon]

You will have shorter o-ring and seal life.

i already had a leak on my spool valve. fluid started to leak out of the detent part on the back of the valve. maybe a defect or problems from heat already.
you would think that the manufacturer would figure these things out.

 

[SWI Don]

My splitter has a 20 gal tank with a 28 gpm pump. After running it as faily hard for about an hour today the tank was warm but you could still hold you hand on it.

A question, how much room do I need to leave in the tank for expansion? There is about 17 gal in the system now. Is there any rule of thumb for amount of air space in the tank.

Don

 

[CylinderService]

Hydraulic Reservoirs

I agree with Ray and others, your tank sounds too small. The rule of thumb in hydraulic design is a MINIMUM of 1 minute’s oil in the tank. Logsplitters often violate this rule, but overheating is the penalty. Hot oil (180 deg +)hardens seals making things leak, but it also gets so thin it doesn’t lubricate well, causing premature pump wear. If you don’t have a thermometer, the tank shouldn’t get so hot you can’t hold your hand on it, like Jags said. You’d like to see no more than 150 deg. F. I’ve seen a few tanks with the paint burned off, which is a little hot.
Using good quality oil helps control heat too. The cheap stuff isn’t really cheap!
As for expansion, generally a couple inches of air in the tank when the cylinder is retracted is sufficient – oil gains a little volume with heat, but not much.
To figure tank volume, multiply width x length x height in inches, and divide by 231. (There are 231 cubic inches in a gallon). Subtract some for tank thickness, and some for air space at the top.

Don the hydraulics guy

 

[jonseredbred]

hey don,
how many gpm do you think my prentice loader pump is? I have overheating problems. it is a 2 stage pump.

 

[CylinderService]

Prentice pump

Most of the Prentice pumps I've seen are Commercial type double pumps, with each section putting out 20-25 GPM. Those big gear pumps last a long time, but they start out pretty inefficient, and get worse as they wear. Inefficiency is expressed as heat in the average system.
So a bigger tank may help, but the underlying problem may be a worn pump which is making a lot more heat than it used to. I think if you touch it after it's been running for a while (20 min +), it will be the real hot item in the system.
I'll be happy to look at it for you if you bring it in.

Don

 

[treesurgeon]

ill tell you what. after splitting wood for one hour, you could put your hand on the hydraulic tank for about two seconds.
perfect for splitting in winter. i will use it as a glove warmer.