Who's the Gresen spool valve Expert/Guru?

stevieb49829 · Apr 2, 2020

I'm needing some info on this J 8 Gresen single spool valve I'm trying to use to control a double action cylinder. The valve is a 4 port, 3 position (spring-to-center) open center, but it only pressurizes one of the two work ports. It seems to be factory, and in really good shape. The ports are all well-labeled. What I don't understand is why the factory would create a 4 port valve to only use one work port for pressure? Or has something been done to make this valve only useful for a single acting cylinder?

Bob · Apr 2, 2020

I've seen a lot of "Gresen" valves but never one that looks even remotely like yours.

It MAY have been custom-made for a specific application on some machine and not be "convertible" to double-acting use.

As you you have found, "Gresen J8" doesn't bring up any info on the 'net, are you SURE there isn't another part number stamped somewhere on the valve?

I believe in saving and re-purposing as much as anyone, but if no info can be found sometimes a guy's just got to quit beating a dead horse and move on.

You can buy a new single spool valve for $80 and up, comes a point maybe that's the thing to do, if no more numbers or information can be found.

J. Schwiebert · Apr 2, 2020

When I worked for Dana and they owned Gresen I taught some Gresen classes we always went by the valve casting number.J8 is not a regular casting number and I would guess the relief valve is under that plug and for monoblock valves the inlet and relief valve are located on the left side.

stevieb49829 · Apr 2, 2020

The casting number is 9 25 B (or 8). That was the first number I used to explore the net, and I got nothing there either. I will use it as a single acting cylinder on my home made 3 point for a while, but I want some down pressure for road grading, so I may have to quit beating the dead horse eventually.

stevieb49829 · Apr 2, 2020

I did find one on ebay that looks just like it. I'm trying to get them to pull the plug next to the handle and take a picture of it for me. Mine has what I believe might be a load-hold valve under the plug, and the pressure relief valve in the same bore, at the back of that valve. I machined a new brass holder for the little steel plug, so the broken part is no longer an issue - other than finding the pieces of aluminum somewhere in the system.

Am I off base thinking 4 port single spools are inherently designed for double-acting cylinders?

I've included a couple more pictures this time.

Bob · Apr 2, 2020

(quoted from post at 19:49:11 04/02/20) I did find one on ebay that looks just like it. I'm trying to get them to pull the plug next to the handle and take a picture of it for me. Mine has what I believe might be a load-hold valve under the plug, and the pressure relief valve in the same bore, at the back of that valve. I machined a new brass holder for the little steel plug, so the broken part is no longer an issue - other than finding the pieces of aluminum somewhere in the system.

Am I off base thinking 4 port single spools are inherently designed for double-acting cylinders?

"The casting number is 9 25 B or 8."

More than likely that's a "date code" from when the casting was poured, "month, day, year".

"Am I off base thinking 4 port single spools are inherently designed for double-acting cylinders?"

Yes.

As ONE example, read about the "300" Gresen valve described at the link bellow.

https://www.parker.com/literature/H...sc bulletins]/Bul HY14-2713-B1 300 400 CV.PDF

"I did find one on ebay that looks just like it. "

Is the auction number 112487898925?

Below is a photo from that auction, it appears the "CYL B" port may be factory plugged with a factory hex socket plug, just like one port is in the "300" valve at the link above.

So, perhaps these valves ARE made for operating a single-acting cylinder only.

stevieb49829 · Apr 2, 2020

"Am I off base thinking 4 port single spools are inherently designed for double-acting cylinders?"

Yes.

As ONE example, read about the "300" Gresen valve described at the link bellow.

So, perhaps these valves ARE made for operating a single-acting cylinder only.[/quote]

So, to clear up my thinking: The body(s) may be cast and machined on the outside so they look the same, but the spool and internal porting can be different enough to make it SA or DA? And the factory plugs just are to clean up the package, when the port is not really being used? Man, am I learning hydraulics!!!!maybe???? Thank you, A LOT!

stevieb49829 · Apr 2, 2020

"Am I off base thinking 4 port single spools are inherently designed for double-acting cylinders?"

Yes.

As ONE example, read about the "300" Gresen valve described at the link bellow.

So, perhaps these valves ARE made for operating a single-acting cylinder only.[/quote]

So, to clear up my thinking: The body(s) may be cast and machined on the outside so they look the same, but the spool and internal porting can be different enough to make it SA or DA? And the factory plugs just are to clean up the package, when the port is not really being used? Man, am I learning hydraulics!!!!maybe???? Thank you, A LOT!

Who's the Gresen spool valve Expert/Guru?

stevieb49829

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Bob

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J. Schwiebert

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stevieb49829

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stevieb49829

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Bob

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stevieb49829

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stevieb49829

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