Load sensing OC steering

I think this is the way to do it if by pilot valve you mean shuttle valve.

Yes, sorry I meant shuttle valveā€¦ (edited!)

@Kaupoi you use the 57C right? Do you have any problems with LS line pressure staying high / tractor taking a while to return to standby pressure? Or do you think the tractors hydraulic system already has a bleed in it / works just fine for you?

Yes i use sp10-57C.
From LS line oil flows to pump LS port. There will be no pressure (except small stand by pressure) at LS line if spool is at neutral position.

In that case it sounds like the tractor has a bleed in it, so it should work ok for me (I hope).

The 57C when in neutral, blocks the LS port, whereas 58C ports LS to tank in neutral (to drain pressure) so with a 57C, it relies on the tractor having a bleed, or else when it shifts to neutral, LS pressure will remain high, and therefore tractor wont return to standby pressure. I assume the tractor must have a bleed though, or else any implement connected that didnt, would cause this problem!

Donā€™t worry about the LS pressure, JD engineers have already done it. :grin:
58C can be used at OC systems without LS line to control priority valve.
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I bought a Hydraforce SP10-58D for my valtra today. It was the only one in stock.12 weeks for the 58C here. I will add a double piloted lock valve and a relief valve.
Hydraforce SP10-58D
I will see if I can make it work, it will probably be a temporary setting. I will receive my SP10-57C in the end of may, just after seeding. I will then test both and tell the results here!

The spools of the 57C, 58C and 58D are interchangeable, same bloc and coils. Spools cost 160$Cad

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In most Ls orbitrola and Ls tractors, the output valves are 2 separate systems (so that the orbitrol has pirvication) If you connect the LS autosterone valves to the Ls line of the general hydraulics, there will be no problem with pressure discharge because in this system it will be solved. However, the discharge of Ls orbitrol relies on orbitrol, if we cut it off with a check or alternative valve and we do not provide another way of discharging, the system will not work properly.

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This is what I was wondering / thinking would be the caseā€¦ I am using the tractors main hydraulic system, not the steering side, didnt want to interfere with any of the steerings 1st priority system at all where I could, other than Tā€™ing the lines to the ram.

That makes sense thoughā€¦

About installing a steering valve on a open center hydraulic system with steering priority valve I think there are 3 options:
1 Install in parallel with orbitrol like I did, it can be tricky, you play with the steering system

2 Install a sort of bloc or unit like the loaders bloc in serial like the others functions but I was afraid this would cut a lot (or all) oil supply to the others functions (I am running a hydraulic motor for seeding)

3 Install a second priority valve after the first so you donā€™t interfere with the steering system.

In ā€œrealā€ LS System the best way is install it like a loader bloc. I saw a John Deere 6430 Prenium with a dealer installed oem autosteer valve and it was piped in the back on top of the hydraulic outlets.(the power beyond)

Thats how I am plumbing mine in, will be testing shortly.

The best solution is always connecting in parallel to the orbitrol line. The P line of the orbitrol is a separate system in which predictable pressure conditions are ensured. In the main system, the use of each of the valves included in this system affects the pressure in the P line !! If EHR or seat valves are in use while driving, calibrating the proportional valves will be difficult in this case. Surely a pressure compensator is necessary then but he will not solve this problem.
Factory installations (I checked in service books) are always connected to the orbitrol line.

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That does make sense / can see where your coming from for sure. On the Deere the steering orbital and brakes are both off the priority one block, so always get priority no matter what.

My thought was more safety though in that I thought, if anything was to fail with my system, it would just pull from the rest of the system, and therefore NOT effect / risk failing the oem steering systemā€¦

I have a pressure compensated flow compensator on the P feed to my steering valve, so i can slow flow down, which should give constant flow under varying pressure feeds (hopefully) unless it gets very low?

@baraki You are right. When I checked the tractor I saw the 3 lines going to back so I just thought it was the power beyond but itā€™s an other (special) bloc near from the orbitrol lines.

Another problem which I wondered if i would get, and after now fitting it, I am, is that by using a pressure compensated flow control valve, it has a feed return and outputā€¦I have it fitted to the P lineā€¦problem being now, if i set the valve to an acceptable flowā€¦ its constantly regulating / dumping oil to returnā€¦so the tractor is loosing all its hydro flow through the valve back to tankā€¦ obviously making all other actions slowā€¦

I could fit a valve before it so its only turned on when steering is active, but even then is going to be far from ideal, so this solution doesnā€™t seem to work wondering wether I would be better just using an inline flow regulator? At least then it would only be seeing flow WHEN the sp57 is asking for it due to having LS port. Trouble is then, obviously, flow isnt consistent, as will change with pressure, so as tractor is at different RPMā€™s / other hydraulic devices are using flow etcā€¦

I think the key really is we need a valve that can operated correctly without needing flow restrictions etcā€¦ Im yet to get mine plugged in, but from what other people have said, the 57C dosnt seem to allow smooth operation without some form of flow restriction?

Anyone have any thoughts on this? @Kaupoi ?

My pressure compensated flow control valve is 2 way, without T line.

Could you post a data sheet of your valve?

I currently have one of these fitted:

https://www.hydrauliikkapumppu.fi/tuote/maaransaatoventtiili-vpr3-g38

But not going to work having the drain port, as just robs flow all the time, which is no good! Going to need something inlineā€¦

Is this what your using?

https://www.hydrauliikkapumppu.fi/tuote/vastusvastaventtiili-painekompensoitu-stuc-g14-10-lmin

May have to swap mine out I thinkā€¦ @Kaupoi

Have found this from my local / next day supplier, looks to be same thing / very similer in design, think ill swap it and try that instead.

This is not about compensation! Valves with which they give a constant flow which does not matter here because the flow needed is different depending on the demand of proportional valves at a given moment.
We need a constant pressure and basically its constant difference in levels at the input and output. I use such a layered valve for cetopes:

Thanks to it, we have a constant pressure difference between the input and output of the proportional valve, regardless of the pressure difference at P and the resistance of the steering.

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Thats not very good for CC systems.

Yes. 18L/min max flow.

Or maybe the smaller one with 20L/min max flow would suite better Webtec Products VFC Hydraulic Pressure Compensated Flow ControlWebtec Products VFC20 Hydraulic Pressure Compensated Flow Control VFC20-K-J - Hydrastar Ltd

That looks much better than my 2 way version.

WIll wait for it to arrive / fit it and find out!