Hydraulic valves

Mtractor · Mar 30, 2015

I have a hydraulic question can I hook four single valves together to like run a backhoe? I will try to post a picture of the valves I am talking about. They are all open center valves and I will be just circulating oil through them.
<image src="http://forums.yesterdaystractors.com/photos/mvphoto18356.jpg"/>

ypop · Mar 30, 2015

You Can put pipe nipples between them but they get wide when you do that! That is why they make the gang valves!
Ypop

Janicholson · Mar 30, 2015

Yes. Be careful to only use one valve at a time. Using 2 at once is very unpredictable as pressure in one cylinder cam (and will) move the other with bizarre consequences. Jim

Steve@Advance · Mar 30, 2015

Don't think that will work for you. When any open center valve is in the center position, all the pressure will return to tank. An open enter valve will only operate one device (like a log splitter cylinder), not a multi cylinder application, (like a back hoe).

For a multi cylinder app, you need closed cylinder valves and a pressure compensated hydraulic pump like this:

http://forums.hydraulicspneumatics.com/eve/forums/a/tpc/f/8621030121/m/6151045182/xsl/print_topic

pete 23 · Mar 30, 2015

You can hook them together but the first valve you use will take all the flow so others down stream will be dead until you return that one to neutral. Probably would not be a problem in your situation but , yes it would get to be a really wide, messy looking arrangement.

gbs · Mar 30, 2015

yea but you can run into problems like is the valve a power beyond type,what is used for a relief valve system,and last but not least you will have to control multi function fluid flow control manually ,you can probably find a multi spool valve from surplus center that will do what you want at less cost

Janicholson · Mar 30, 2015

Pete 23 is correct. When put in series, they work. Reservoir out to inlet on the next. Jim

Steve@Advance · Mar 30, 2015

I thought about seriesing them together, guess it would work, but sure gonna put a lot of pressure on the stem seal orings. Never tried it. Depend on how much and how hard it got worked as to how long it would last.

jm. · Mar 30, 2015

Surplus center is your best thing. You can buy stackable valve cheaper than you can rig that up.

Heat Houser · Mar 30, 2015

Let's look at extending a cylinder.
The down stream valve(s) will have the return oil coming back from the cylinder to use as it's supply.
Open center in series is very dangerous unless they are power beyond.
When you are extending a cylinder and the rod side oil is returning.
In this case, the cylinder can be acting as a pressure intensifier due to the area difference between the piston and the rod.
The second valve will be exposed to this pressure if it is operated.
The second area of concern, the relief in the first valve dumps to the tank port which feeds the next valve.
If both valves are operated, the work pressures will stack and you may crack housings, blow up pumps, blow hoses.

Do not plumb open center valves in series unless you use power beyond.
Then each valve has it's own tank line and the pressures cannot stack.

J. Schwiebert · Mar 30, 2015

I would go to some truck equipment shop. Also do you need any spools to have float position? Do you need any circuits to have different relief pressures? I would get a good valve like a Gresen V-20.

mEl · Mar 30, 2015

Heathouser has it exactly right, I put the very response on the Case forum to no avail, people will do it anyway, if the relief is in the first section and the second section is deadheaded the relief valve is effectively taken out of the system as pressurised oil backs up against the backside of the main relief, rendering it inefective, A power beyond type valve with individual drain lines is an absolute necessity, you cannot safely series garden variety valves in series , the exception to this would be to install a relief valve block with a drain prior to any valve stack, even then you have areas inside the valves that are handling pressures they were not designed for as these areas would normally be going to sump, now with the pressure flo through the whole valve assemble sees high pressure. Its not as simple as just throwing some valves together

VicS · Mar 30, 2015

Sorry buddy don't think you are right. 580M case backhoe has open center Hyd. Loader and backhoe valved are all stacked. Has just one pressure relief valve and it is on the loader valve. Vic

Traditional Farmer · Mar 31, 2015

I 2nd Surplus Center, over the last 5 or so years I've bought hyraulic valves,hoses,fittings,motors and pumps and they have all been good quality at a very good price.

buickanddeere · Mar 31, 2015

You will hate it with a pasion. Find a proper six valve bank with joy sticks somewhere, somehow.

mEl · Mar 31, 2015

(quoted from post at 09:15:54 03/31/15)
You will hate it with a pasion. Find a proper six valve bank with joy sticks somewhere, somehow.

Vic, I spent my life working on Case hoes (50 yrs) and am very familiar with their systems. The Case hoes before closed center never had a stacked valve without a 3rd line to sump. All recent, since some early Case systems use the loader relief to control backhoe pressure as well so the protection from the low pressure being subjected to the low pressure circuits within the loader valve is taken to sump by the 3rd (tank) line off the loader valve.

The hoe valves have a dedicated low pressure circuit which goes back to the outlet to tank from the low pressure circuit within the hoe valve. Case uses a poppet and spool to direct low pressure back into the high pressure to suppliment pump flow as when the boom is dropped into a deep hole to prevent cavitation.

All Case systems are designed to keep oil pressures from bearing against spool seals and returning to the backside of the main relief.

Hydraulic valves

Mtractor

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ypop

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Janicholson

Well-known Member

Steve@Advance

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pete 23

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gbs

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Janicholson

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Steve@Advance

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jm.

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Heat Houser

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J. Schwiebert

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mEl

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VicS

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Traditional Farmer

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buickanddeere

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mEl

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