Ok, so I had this mad but doable (I think) idea. I have two small single acting rams for two sections that I want to control on a machine. When rams are extended (filled with oil) they shut off the sections, simple. Is anyone able to come up with a way of running these off the tractors load sensing hydraulic supply so I can simply hook into it when coupling up the machine? I need a load sensing block and room for two valves. I have some idea of what I need but I’m sure there are people in the group who are much more knowledgable with hydraulics and valves and know exactly what’s required. If I can’t use load sensing the only other way I can think is to use a spool valve and incorporate some sort of pressure relief into it to stop back pressure on the tractors pump. As always, any help is appreciated and any ideas anyone has would be more than welcome 
Thanks!
I understand your tractor has load sensing hydraulic system… So you could have option for “Power beyond” meaning P, T and LS outlets… could be possible to a remote “stack” valve. Different types possible… Single acting cylinder? what flow? need proportionnal? Electrical control I guess?
Yeah exactly! P, T and LS lines, I can measure cylinder size tomorrow. Both are single acting cylinders. Flow, this is where I need someone with the brains I don’t have, it needs to move the cylinder pretty quick but without causing too much stress. No need for proportional, open/closed is good enough. Electrically controlled yes so I can use along with AOG software! Can you help? 
from how you describe the operation, they look like the two sections of a traditional fertilizer spreader, if so, I would use a simple two-element single-acting hydraulic block without LS, with the maximum pressure valve set at a “low” pressure (enough to move the pistons), connect a distributor of the tractor and feed the oil continuously, then you time the signal of the section control long enough to allow the piston stroke
If the tractor is from the LS, then you need a block with LS, because how else to get the pressure on the P line. It’s simple, it can be assembled from standard Cetop sandwich blocks, or another way is to use alternative check valves, a controlled check valve would also be needed ( castle)
There is another possibility, use one section of the tractor’s hydraulics, set a low flow and connect to it a normal section with an open center.
For me, such a complete 2-section LS splitter costs about 300E as in the diagram
LV1-063/M
2RJV1-06/MA
remote valve from LS tractor system can work even if not perfect:
- In case of Closed center, standby pressure will be max pump pressure (say 190 bar)
As it should be 25 / 30 bar if true LS - In case of open center flow will be constant in neutral (too much if not limited); should reduce flow per using tractor valve (SCV element with flow setting option) as baraki is proposing…
(“Less bad solution”) (true LS for sure better!)
Thank you all for the replies and solutions!
@baraki when I don’t activate valve to pressurise the cylinder, how does the oil escape back to tank to retract cylinder?
If single effect cylinder in neutral A or B port should be connected to T Tank
Then mechanical return can be thanks to load or spring
According to the diagram I have attached:
Feeding on the coil No. 1 -----> extending the piston
Middle position (coils de-energized) ----> piston locked in a fixed position by a lock
Coil No. 2 power supply ------> oil flow from the piston to the T-line (lock unlocked)
Should this one work as well?
(Cartridge / Manifold design here by Hydraforce)
Something is wrong :flow will pass direct to tank when energized.
It seems you us a LS valve and add extra LS
This might be the one for your setup:
This pattern is wrong! Ls cannot be permanently connected to the piston line because there is usually a leak in the Ls line, so the piston will not hold, if there is pressure in the piston, the pump will be controlled on the output when it is not needed.
That’s why there is a lock on my schematic.
Valves are bad too, P can’t be up to T like Lars noted.
I realize my mistake… Was trying to find a simple, cost effective, compact design thanks to Cartridge / manifold… second valve proposed by @larwest would not be “closed center”…
I dont understand why LS line should not be connected to outlet port: for me it should be the normal way
This one better? (if not, curious to see how to design LS valves as single acting (one solenoid), impossible?)
A made circuits the way I would do it.
I would use limit switches to stop pressurising the system when cylinders are fully extended.
Limit switches maybe not needed for LS system
For Load Sence circuit
For Open Center (SCV) Always a little flow from tractor:
The LS is normally leaked to tank by specified orifice in the tractor system.
I was focused on keeping port 3 as P like you started out, then 1 to tank and 2 to cylinder.
Both yours and mine , the rest pressure between LS04-B30 and cylinder leads to tank.
Hello Pat you dont implement LS!?
@Larsvest This requires different valve to move pressure from port 3 to port 2? Or not? Im a little lost 
What is approximate cost behind a schematic like this? Does anyone have an idea?
I have no practical experience with Hydraforce, but this is what they write in their spec sheet for the one I linked to earlier (click above link to get to SV08-30 )
By looking at the arrows in the diagram I think it work best with P at 3 and T at 1.
And as they write “1 is not intended to be used as the inlet” but I believe it could be used “wrong” way though.
Description
A solenoid-operated, 3 port, direct-acting, spool type, screw in hydraulic directional valve. When de-energized, the SV08-30 allows flow from port 2 to port 1, while blocking flow at port 3. When energized, the cartridges spool shifts to open from port 3 to port 2, while blocking flow out port 1. While port 1 may be fully pressurized, it is not intended to be used as the inlet
EDIT: 12 jan 21
One place in europe, to get 2 valves and one shuttle valve
| Part name | Can be shipped now | Shipped later | Quantity | Own comments | Price each | Total | |||
|---|---|---|---|---|---|---|---|---|---|
|
Shuttle valve 1/4 BSP |
Part number. 46506|1|0||Please enter your own comments|€21.30|€21.30||
|||Selector valve 3/2, 1/4 BSP, 12 V
Part number. 63663-12|2|0||Please enter your own comments|€157.00|€314.00||
Total
€335.30
@jpsw5960 You told us your tractor have LS, and then as flipper80 posted earlier.(
“As it should be 25 / 30 bar if true LS”)
So is 25 bar not enough to move the Ram cylinder?
Does the Rams tolerate max pressure?
And how do you activate the rams today? (eg. connected to 2 different outputs, one for each section, and then activate lever in tractor to close section— return lever to neutral to let section be “closed”, and then move lever the other way to open section again?)
I apologise, I do not know. It is a New Holland TM155 if that helps.
Yes connected to two different outputs, I pull the lever, oil goes to ram and section goes off. I put lever into float position and oil returns free by spring to tractor and section goes on. One section is for a Grimme potato planter and the other is for a front fertiliser applicator. I eventually want to use it to automatically add headland to field using agopengps to save time when planting so I do not have to manually measure the headland and mark it. I’ve wanted to do this project for a couple of years now and I finally have a little time before spring planting starts again to give it a go