Hydraulics Questions

Just dropped a small fortune on some "convertable" Cross valves for my loader, which will allow me to put all the plumbing outside the cab with only the levers being inside.

Got the "single acting/double acting" thing all figured out, but answer me this:

Each valve has an independant regulator built in, also is built with an "In" port and an "out" port.

Bear in mind that the loader's system already has a dedicated pressure regulater back at the pump. "In" oil will already be pressurized.

#1: Can I "stack" the valves by running the "out" port of one valve right into the "in" port of the next valve? Then, the "out" port of the last valve would just jump back to the tank?

#2: Can I "gut" those "valve regulators" and just rely on the loader's system pressure?

In other words, I just want to use the new valves' spools and the channeling of the valves to direct oil and release oil.

Hope this makes sense and thanks,

Allan

Ted

This is what I'm trying to explain.

I don't want "power beyond" because it would divide the flow and cut the speed. I need the gallons because these are some hefty cylinders and it takes a lot of oil to run ‘em at speed.

I want one oil, available and piped in series with three valves operating singly, one at a time, not "at the same time" or "any two operating at the same time".

Right now, I've got the grapple plumbed into the 12 gmp tractor pump and at 12 gmp, the speed is slowed by at least 1/2 of normal.

Hope I'm making myself clear. :>(

Allan

Also, you are not understanding how the "power beyond" function works with valves for an open-center system.

It is more complicated then you think. There are extra ports in the valves and extra internal passages and "lands and grooves" in the actual "spool" in the valve. That's why those valves are more expensive.

If correctly set up, using valves designed to be set up like that, you will STILL have full flow available to the first spool. The power beyond port will connect to the next valve in the series, where the "power beyond" flow will be blocked UNLESS that spool is moved from center.

So, if the first spool lifts the loader, you will have full flow there, UNTIL you move the second spool from center, say, for bucket tilt. ONLY THEN will the flow be split, and, yes, the lifting of the loader will slow down BUT ONLY WHILE THE BUCKET TILT IS ACTUALLY IN USE.

This is what the dealer came up with unless I wanted to spend mega-bucks. Bad enough the way it was. :>)

Allan

A power beyond is only usefull if you want to "multi-task" as you say. It goes on the first stack in line and allows a percentage of oil to flow to the next stack while operating the first stack.

Just curious, is there a reason you are using single spools? Are you looking to make one a motor spool as a second use when the loader is'nt on or something?

This project is "evolving" minute by minute.

Main problem was that the system uses both single acting and double acting cylinders. This is the only vavle I could find that could be "set up" either way.

Now, since I ordered the valves, I've hooked up the double acting grapple to one of the tractor's remotes. The grapple is almost painfully slow, but it does function to the point that I could live with it if necessary (if I don't have enough room to mount all three valves on the fender).

My biggest worry now is that the lift and tilt, which both are single acting, will be slowed by using these generic off the shelf valves.

Paper work says that they leave the factory @ 1500 lbs and 10 gpm but can be set up for 2,000 lbs and 25 gallons per minute. Darned lift cylinders are something like 3" in diameter and I'm concerned that 10 gpm just isn't gonna get it. That's why I wanted to yank the regulators out (to remove their restriction?)

However, if they "bypass" internaly to the "out" port, guess I can't remove 'em? :>(

I'm getting myself lost here. :>)

Allan

If those valves dont have a screw and lock nut behind the cover, you can still usually shim them to a higher pressure with no problems. Pretty much all these bypass valves have a spring in them. This spring can be shimmed to increase the pressure much the same way as turning the screw on an adjustable one. The only thing is, if you really wanted to know what pressure you increased it to, you'd have to plumb in a guage.

I'm still a little vague on your "set-up" for the single action. Are you plannning on bypassing the oil in the "non-working" action? That would increase the heat build up considerably. If you want to simply send the oil back from the valve as you lower the loader, just run a short section of hose from the non-work port to the "out" side of the final valve body.

There are other ways to plumb this machine if you want to use the tilt while lowering the loader.

Also, I should say that I may have missed an earlier post or something, so we are talking about an open center system, right?

Ok, you've "converted" the valves to one-way, so the oil is supposed to flow from the non-work port to the out port when lowering the loader or tilting the bucket downward, right? You asked about simply plumbing them in series. No problem.

As far as getting full pump "volume" to the cylinders, those valves you bought need at least 1/2" work ports. I think a 3/8" work port with a hose of any length hooked to it, might restrict the flow enough that you'll have problems. Though, you did'nt state the pumps size or output, so I'm guessing it should be at least a 20-25gpm size, right? What size ports are on the loader lift cylinders?

We're talkin' now. Both the loader and the valve has 3/4" in and out; 1/2 work ports.

Pump is a PTO pump. Think it is 19 to 21 gallon. Don't know the pressure; I'd guess somewhere around 1500 lbs.

Thanks Pard,

Allan

They won't mount right.

I don't have any room. There is one place where they will fit just off the left front of the seat armrest. I've got just about 6 or 7 inches to mount the valves outside on the flat fender and poke the levers thru the cab at a 3" wide space under the window so that they will be positoned right at my left hand.

Hard to explain over the phone, but there is only one place in the whole darned cab that will allow me to pull this off. It really is a tiny cab.

Allan

If the first valve is in the neutral postion (not doing any work of lifting or releasing), any oil entering the "in" port is just gonna be routed to exit the "out" port. Right?

I don't care if I can only use one function (lever) at a time. That's okay.

Allan

Valves that are rated for power beyond may have a more complicated spool and porting design plus a stronger casting and only have one outlet port (many industrial valves are so configured).

Most of the time, with agriculture grade valves they supply a “power beyond sleeve” that separates the center port and the actual tank port function and creates 2 outlet ports, one for tank return and the other for center port fluid to pass on to additional valves for power beyond. This scheme separates the large area of the casting involved with the tank functions from the backpressure created by the operation downstream valves this reduces the chances of blowing out the casting of the valve. In addition backpressure on a non- power beyond valve can cause the backpressure to unbalance the spool and make the valve hard to shift under certain operating sutations.

Before you connect them as proposed you better check with Cross about the power beyond capabilities of the valves. It that is permissible then the relief valves need to be set so that the valve closest to the pump has the lowest setting and set the others to maximum so that in normal operation they do not function.

I am in agreement with those recommending the stack valve.

However, the original setup would only allow "down tilt" while lifting or "down loader" while tilting up.

So, I'm kinda used to this "clunky" way of doing it anyways. :>)

Allan

That's why I'm asking.

Those darned regulators will limit the flow to 10-gpm, which is waaaayyyy lower/slower than the original system. That just will not do.

I don't see why I can't just pull that regulator cover, remove the regulators guts and put the cover plug back on? That would allow the original systems pressure and flow to go right on thru to the spool and out?

Really working with a "space restriction" issue here; due to the way the cab is built, this is the only valve that I've found that will "fit" and I'm thinking of just tiying the valves together with some close nipples?

The only thing I think I'd be loosing is the "multifunction" of more than one valve at a time. It would be like running a F-11 loader vs a F-10, but I can live with that.

Thanks,

Allan

5 gpm moves a 3" cylinder 8" in 5 seconds. Moving that 3x8 cylinder faster usually means banging the piston against the end because the operator can't react fast enough. Heaving a loader from ground to 6' in 10 seconds tends to toss the load or the operator out of the seat as it jerks the tractor around. Sure you can feather the valve if you sandpaper the calouses off your fingers in preparation for safe cracking. With the flow set back to 5 gpm, you can wear ski gloves and still not break things with the hydraulics.

You would be best off to reject these single valves without power beyond and go buy a stack valve assembly from Northern, Baum, or Burdens with two sections MADE for single acting, and one section made for double acting. The sections cost the same either way.

You NEED the power beyond connections for your single valves so they work like a triple valve otherwise they won't work well.

Gerald J.

It's coming along. Right now, I've got the original controls positioned to poke thru where the door would normally go.

I'm gonna drag the whole shootin' match up here in the hills today and get it straightened out as far as the cab insulation, engine heater, cab heater and these hydraulic controls. Then, I can hang the door.

It's a tiny cab, not much room and I sure don't want to loose that "fast" feature of the original hydraulics. That's the reasonwhy I like the F-10 loader.

That big brute really "moves the mail". :>)

Allan

This is the valve I bought to run my Koyker loader. It gets its supply from the single valve in my 856. It dumps back into the rear end through a fitting I put down under the seat. It just dumps into the rear end. It does sit inside the cab, I haven't worked out how to put the valve outside and still be able to control it.

It is a Prince valve I bought from surplus center. You would still need one more spool to run the grapple but you can get power beyond hookups for just a little more.

Rob
ROb

Ted

The valves are 25 gmp valves, but set up at the factory for 10 gpm.

If I completely gut the PR valves, they would "bypass" to exhaust? They wouldn't bypass to the spool first then on out the exhaust?

Allan