Gresen 3 spool valve, can anyone tell me about this one?

[nhironworks]

Hi,
I have this valve set, see pictures. Very well built and made by Greesen which is now owned by Parker I believe. I think it was on a larger tractor loader, but do not know what make. I cannot find info anywhere on it. I would like to know if it has power beyond capabilities, and if it is an open or closed center. I think it is set up as an open center now as when I put air to it it flows out the outlet unless I pull a control handle, but when all valves are in center is flow through. Can this be changed to closed center? I see some plugs and thinkgs external to the unit, what are they for? Thanks so much for any help, greatly appreciated. Eric

 

[J_J]

Is your tractor closed center?

It looks like you have a PB port there and if you know the manufacturer, you can maybe order a closed center plug. Take a pic and send it to Parker, and they should be able to ID if no one here recognizes the valve.

At the present, it could be open center or closed center.

The difference is that the closed center plug will block off the main gallery, and let only the cyl fluid exit the OUT port.

To test for closed center, try to blow air through the valve like you did, and if it is closed center, no air will exit anywhere.

With levers in neutral, if air flows out the OUT port when you blow air in the IN port, then it is configured for open center.

The third spool is blocked off, but could be used for the grapple.

 

[nhironworks]

Hi JJ,
thanks for the reply. I did test it and figured it is an open center as air did exit the OUT. Hoping to find out if it can be a closed center, and if it has PB capabilities. Thanks again, Eric

 

[J_J]

The outlet is there. The plug that is in there now is for open center.

Remove the large plug from the end center, and look inside. You should either see a small threaded hole or a about a 3/4 in hole.

These are an example of three plugs that could go there if it is not the small hex screw.

Left plug is open center
Center plug is closed center plug
Right plug is PB

 

[nhironworks]

Thanks JJ

 

[Leejohn]

You said ( I think it was on a larger tractor loader). I wouldn't think so, because it doesn't have load checks and all spools are just spring center. It could maybe be a motor spool valve, but I don't know how to tell you how to check that.