Valve screwing with my head

[J_J]

You will need a splitter that will divide the pump supply for the hyd motor.

Something like this with a 60 GPM capacity.

Divides the flow into two equal paths.

This valve is only 8 GPM. Prince or Parker might have one you need.

You need a 0-60 GPM capacity divider valve.

3/8" 0-8 GPM DIVIDER VALVE

If your PB is before the splitter, everytime you move the valve lever, the hyd motor and everything after the splitter will slow. will slow.

If the 60 GPM pump is all the flow, the flow needs to be split before any other valve.

This will allow each side, A, and B, to have a dedicated supply.

 

[muddstopper]

JJ, I understand what your saying, splitting the oil as it comes out of the power beyond and operating the splitter would rob the oil from my hyd saw that I need the 30gpm to operate. That would not be acceptable. I havent purchased a pump yet, so i will throw this at you for an opinion. If I purchase a stacked pump with 2-30gpm sections. I run one section to the saw motor valve and then thru power beyond and then combined that oil with the 30gpm of the other section and then run thru the splitter valve for the splitter cyl, and then back to tank. How would this work. I will also have another pump to control some other functions that would be completely seperate from this circuit. My thoughts are, One, when sawing, I need full power and flow, so going thru the saw valve first should provide me with what I need without the saw speeding up or slowing down when I am also running the splitter. Two, since the saw most likely, or very seldom, need any power while splitting. I am thinking that once the round is sawn and dropped into the splitter trough, there will be a short period of time that would be needed to advance the log and clamp it for the next round. Log advance and clamp will be thru another pump and control valve so wont effect splitting or sawing. If the sawing and splitting operation do overlap, saw will be a full power and splitter would still be at half speed. Even at half speed, its probable the cyl would be a full retract by the time the saw cuts thru the next round. Since the cyl need the most flow for extention,full extend should be complete by the time I have the log ready to saw for next round. We are only talking about 4sec for full extension. On retract, cyl need less flow and will retract faster. As a operator, I would have to be mighty fast to advance a log and have it fully sawed in 7 or 8 sec, the time it should take the splitter cyl's to cycle

 

[CJONE]

Brand Hydraulics makes one that is adjustable and is good for 90GPM. 3 ports "in" and CF for controlled flow and EF for excess flow. Both out ports can be used as pressure feeds. You would set the CF port to a fixed flow then the excess flow would be used for a non speed required circuit. You will need a relief before this unit or 2 reliefs in each circuit after the F/C. Your control valves should have this. CJ

 

[muddstopper]

Cjones, I hope you read my post above yours as i need a opinion on doing this. I will look up the Brand Hydraulics site and read up on the valve you suggested.

 

[muddstopper]

I dont know if this will show up, but is how I am thinking to plumb this hydraulic circuit

 

[J_J]

To pump 60 GPM at 3000 psi you need 116 HP.

What engine do you have in mind?

 

[muddstopper]

190hp international diesel. what do you think of my drawing of plumbing the twin 30gpm pumps. Will this work

 

[J_J]

Should work.

 

[muddstopper]

Might work, but I think i am going to have other problems. #1 problem is trying to figure out how to reduce pressure for saw circuit while maintaining max pressure for splitting circuit. I guess i could set the pressure at the saw control valve to match the splitter pressure, and then add another relief to the saw motor off of the work port. the motor only needs to turn one direction. this could start to look like a spagetti junction. I'll have to think about this a little more.
Edit:
I could be over thinking this. The relief for the saw control valve should only dump to tank once relief setting is reached while in the work position. If valve is in center, flow should pass thru power beyond at pressure needed to operate function, and relief pressure would be adjusted at the splitter control valve. Is this correct? How do i make sure flow and pressure provided by seperate pumps is equal and one pump doesnt over ride the other pump.

Edited again as i keep over thinking this.

If both pumps are providing power for one valve, and both pumps are capable of reaching relief pressure, wouldnt the relief on the control valve, (splitter valve), be all the relief i would need.

 

[CJONE]

Cjones, I hope you read my post above yours as i need a opinion on doing this. I will look up the Brand Hydraulics site and read up on the valve you suggested.

The best way you can do this is by having a dedicated pump circuit for the saw and the splitter. Then you can use another circuit to operate the remaining functions. You may need a 4 or 5 circuit pump. Adding a circuit to a pump is cheaper and more efficient than trying to split hydraulic flow. I do this quite a bit and I will not use flow dividers unless I absolutely have to. The power unit pictured has 6 separate sections and can run 10 different functions. 6 at the same time, if I remember right total flow is 120gpm, 175hp power unit with 8k AC power. The total use at one time does not exceed 150hp so this size engine is sufficient. Over the years I have learned to stay away from flow dividers for high flow systems. CJ