Gresen 2712 Control Valve power beyond?

[J_J]

The specs say your tractor is a closed center system. Which means that you are not concerned about PB.


TractorData.com John Deere 3020 tractor information

http://www.everythingattachments.com/John-Deere-3020-Attachments-specs-s/4209.htm

That may be a closed center plug in the picture.

http://www.surpluscenter.com/item.asp?item=9-7676&catname=hydraulic

The joystick valve also has a CC plug available.

 

[MNBobcat]

I haven't been able to find a price on the PB valve. The part number is K-SP-75-Y (08650130). Parker (who bought Gresen) doesn't have pricing and the local Parker dealer wasn't much help.

 

[J_J]

Read my post above.

 

[Leejohn]

The valve you have now doesn't look like it has load checks, so I would get another valve and use that for my remotes.

 

[MNBobcat]

The specs say your tractor is a closed center system. Which means that you are not concerned about PB.

I don't usually need to be spoon fed information but in this case I don't know anything about these control valves. I assumed regardless of open center or closed center if you want to add another spool you need Power Beyond in order to get the hydraulic fluid over to the new control. Could you explain why with a closed center system I don't need PB? How would I plumb it without?

The joystick valve also has a CC plug available.

Don't know what a CC plug is.

 

[MNBobcat]

The valve you have now doesn't look like it has load checks, so I would get another valve and use that for my remotes.

What purpose do the load checks serve? The valve I have now I assume has been on the tractor for 20 - 40 years.

 

[Leejohn]

When you move your lever from n to up or down it well only let the load drop just a little before it starts moving the way you want to go. If you move the lever slow you can see how it works. Without load checks and you want to go up real slow it could drop way down unless you move the lever to give it more oil.

 

[J_J]

A CC plug is a closed center plug. It blocks the fluid from from going downstream. and keeps the galleries charged at the tractor pressure.

You connect all the valves in parallel. You tee all the valves to the pressure line. Each OUT hose can be teed also and then to tank.

In an open center hyd system, all the valves are in series, and fluid is flowing all the time. You need PB to connect all the valves in series.

Some valves can be converted for either system by using the correct plug/sleeve.