Depth of Hydraulic Suction & Return in Reservoir?

[b52c130]

I am currently building a log splitter and have a question about how much hydraulic oil 'cover' must be over the suction and return ports in the reservoir tank to prevent 'whirlpool' air entrapment on the suction side and 'foaming' on the return side. The reservoir tank is being made from an old Craftsman horizontal 20 gallon air compressor tank that has two 1-1/2" bungs along the 'mid-line' of the tank, exactly 1/2 way up the side of the tank and separated about 18" from each other. The tank is about 18" in diameter and about 34" to 36" long.

The system will have a 1" suction line with a 13 to 14 GPM pump being run by a Kohler 10 HP motor. The pump is an old Sunstrand with an integral 'spin-on' filter (don't know if the filter is on the intake or pressure side of the pump as it is completely 'integral'). The pump and motor came off and old (late 70's) vibratory compactor. The pressure side of the pump will be run in 3/4" to the control valve. The control valve has 3/4" Input and Return Ports. The return line after the control valve will be immediately increased back to 1" to reduce the velocity of the returning oil into the tank. The maximum PSI in the pressure side of the system will be limited to 2,500 PSI.

I am expecting to have about 5" of oil cover above both ports in the reservoir tank. Will this be enough cover or do I have fashion some type 'downward' pointing piping within the tank to prevent both air entrapment and foaming of the oil?

Thank you for your replies and answers.

 

[J_J]

14 GPM at 3000 psi requires about-- 29 HP.

14 GPM---2500 psi --------------------24 HP

5 GPM at 3000 psi requires about--- 10 HP

6GPM-----2500 psi---------------------10 HP

 

[b52c130]

Thank You JJ - Well I guess that the pump is 'under-powered'. I just re-checked the spec's on the 15 Series Sundstrand pump and they are .913 cu inches per revolution, Max 4,000 RPM, and Max 3,000 PSI.

I got the 14 GPM by taking .931 x 3,600 Engine RPM = 3,287 cu inches / 231 cu inches per gallon = 14.3 GPM.

I guess that the 'from the factory' Kohler 10 HP motor is then 'under-powered', but this is what was on the Case W-110 (non-vibratory) Street Roller for propulsion. In any event, the splitter is going to be used in Colorado and 95% of the wood will be Ponderosa Pine, which should split pretty easily. What ever it does, is what it will be. The 10 HP (low hours) electric start motor, pump mount, Sundstrand pump, and separate TRW motor with integral caliper disk brake were a 'friend' salvage bargain at only $200.

I checked further and the integral 'spin-on' filter is on the pump 'in-put' side.

 

[Johnp33]

Re: Depth of Hydraulic Suction and Return in Reservoir?

If it is an air tank it should have a port in the end I would use that as the outlet, you want the oil to travel as far as posible to allow the air out and to cool. The suction line must have a filter, the return line it is a very good idea to have a filter, even if only for the cooling effect.
The return you want that about as you have it 5 inches under the oil level.
You want a fill plug with a dipstick and a vent.
Just a thought!

 

[b52c130]

Attached are a couple of pictures of the beginning 'lay-out'. A 10" I-Beam is going to go down the middle of the trailer and stick out the back of the trailer about 4' for the loading of un-splits, the wedge and the 'splits' table. The 'passenger' side of the trailer will be a 4' aluminum diamond plate tool box for chainsaws and other tools.

 

[b52c130]

?? again ??

 

[J_J]

Re: Depth of Hydraulic Suction and Return in Reservoir?

With 5 GPM, you might get away with the Prince LSR 3060 log splitter valve which will give you increased speed until you need the pressure to split hard stuff.

http://www.princehyd.com/Portals/0/products/valves/LSR3060Flyer.pdf

 

[b52c130]

@johnp33 - 'Thank you' for your response. It does have an integral 'spin-on' filter on the suction side of the pump. The tank also has two 1/2" ports on the top of the tank. One will be used for the 'breather' and the other for a dip-stick and 'fill' location. (the initial 17 to 18 gallon fill is going to be a 'pain'). So, I guess from your reply, that the 5" of cove will be sufficient for the 'return' side. Do you think that 5" of oil depth is enough for the suction side?

@JJ - 'Thank you' for your suggestion about the valve. I will check it out.

 

[DRL]

It does not look like it would be to hard to modify the tank mounts (legs), and roll the tank about 45 degrees so the 2 bungs on the side would be deeper in the oil. Or, 90 degrees and they would be on the bottom.

DRL

 

[b52c130]

Thanks DRL. I think that I will just go ahead and weld something up to direct both the intake and return downward inside the tank. It is not very much work and I would rather do it before filling the tank with oil and then having problems with it.

Thanks to all for their suggestions.