Open center hydraulics

[Rch]

In different tractor brochure they refer to "open center" hyrdraulic system. Could someone explain to me what that means? I assume there is a "closed center" system but I've never seen that refered to. Thanks in advance,RCH

RCH

[MChalkley]

In an open center system, all valves must pass the hydraulic flow back to tank when they are in their center position. Putting a closed center valve in an open center system will cause the relief valve to operate all the time, burning up the pump, or the oil followed closely by the pump.

In a closed center system, the valves block all hydraulic flow when they're in the center position. Putting an open center valve in a closed center system dumps all the pressure to tank and prevents the other systems from getting any pressure.

You can sort of envision a closed center system as a parallel circuit, if you have any knowledge of electrical terms, and an open center system as a series circuit. The analogy isn't totally accurate, might help you picture what's going on.

Mark

[gordon]

That is a very good analogy the two systems are very much alike in that reguard.
Open center usually pump runs all the time.
Closed center pump runs only when being used.
Gordon