Strainer or Larger Suction line?

[IceStationZebra]

Kim, I don't disagree about the reservoir size though I will say that off-road equipment breaks that old rule-of-thumb all the time. I am an engineer and have worked for several OEM's and on one project it was only 1/4-1/3 the capacity of the pump at full RPM. Industrial applications still tend to stick with the 1-2x pump flow, or more.

The biggest issue is aeration. You would be surprised how long it can take air to rise out of the hyd oil. We cut the side out of a reservoir and put a piece of plexiglass on. We ran the machine till it was hot then shut it off. It took a good 20 minutes for most of the bubbles to rise 18".

ISZ

 

[David Devuono]

I understand the 2-3 x rule for tank size but realistically, I don't want to carry 200 lbs of hydraulic fluid on a 1000 lb machine. I have a large cooler to take care of the heat. Besides, I don't even know if this thing will move. While I bought a weld on fitting to install a larger filter screen, I think I will go without for now and use a 1 1/4 id suction hose.

 

[David Devuono]

pump mounted under engine tray

 

[J_J]

Are you saying that you have a 18 GPM pump? A pump that size at 3000 psi, will need a 37 HP engine.

My Power-Trac, will pump about 22 GPM using all three pumps, and needs all of the 45 HP

My hydraulic tank holds 20 gal and the machine has a hyd radiator and fan.

 

[David Devuono]

Interesting that when I first indicated I had a 10GPM pump I was told in need 15hp. Then I see that someone using a 28gpm pump for a large log splitter needs 16HP? I realize a log splitter is mostly filling an unloaded cylinder and just a short high pressure cycle. I have a pump that is rated for 2500PSI and 10GPM at 1000 RPM (3,000 RPM max). I will be running this pump at 1650 RPM (Engine govnd at 3300 RPM) via 2:1 reduction. So in Theory thats about 16.5 GPM. My motors are rated for 2450PSI. I have no experience with hydraulic motors but the specs say it will produce 3,000 inch pounds intermittently. so if I run my system at 2450 PSI two motors will produce 500 ft lbs torque into 10 inch dia wheels. Anyway, I have seen so many different opinions, I will just have to try things. I will start with 2000 PSI and work my way up to 2450 if necessary to make this thing turn. If it still does not have enough power, I will consider further reduction between motor and drive wheel. If it lugs my 27hp engine but otherwise has power, I will change my engine pully.

 

[KWentling]

Simple formula: GPMxPSI÷1714=HP. Your engine should be big enough.

Kim

 

[Ford tractor]

If I understand, you are trying to put a strainer in the return line at the reservoir tank --Yes?

If so, I would ditch the strainer, keep the larger line diameter and put a filter with a bypass in the housing set around 25psi on the return instead. 5 micron media and a 8" canister would be fine.

Strainers just catch big things like marbles, but it's the little specs of stuff that ruin the pump, motors etc.

 

[David Devuono]

Strainer was to be on the suction line. It would also have a remote filter on the return line. I will probably take AKKAMAAN's advise and look for a filler strainer. (now I have various Strainers and weld on ports in my collection)

 

[J_J]

David,

Can you tell us the cu in of the hyd motors, and pump, and the max rpm?

Is that one pump for each motor, or one pump for both motors.