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| It usually takes two changes of the valve to convert to closed center from open center. One is replacing the pressure relief valve with a plug, you don't want the constant high pressure of the closed center system leaking. And where the open center valve can have a power beyond and a constant flow return line, the closed center has the return only from the back side of the cylinder (or motor return) and can have a power beyond, but the main pass through of the open center has to be plugged. The valve makers sometimes make the parts to do that. If not it can be difficult because they didn't plan for it. I have done it for valves on my three point back hoe, though some of them were shot and I replaced them, but ran it on an open center system until I moved it from my MF-135 with auxiliary pump to my 4020 with closed center. It wasn't very expensive to buy the plugs needed from Baum Hydraulics. http://www.baumhydraulics.com It will help to know the exact Cross number to find the conversion plugs. Force might be another source of the conversion plugs. Section H of the Baum Hydraulics catalog shows how the conversion plugs work and the valve has to be made to work with the conversion plugs. It may take contacting Cross to find if there are plugs to work.
Gerald J. | |
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cross valve for a open and closed center hydraulics
