Hi all, Having an issue with my PO check installation. D03 manifold, D03 dual PO check samwitch valve. 6.4 GPM. Open center D03 valve. Gear pump. With the valve not shifted the manifold psi gauge reads about 100psi. Shift the valve to extend the cylinder and the gauge reads about 400 psi on the manifold. Go to retract the cylinder and it reads whatever the R/V is set at, cylinder still extends just a bit slower than it should. PO ratio of 2.4:1, 70 PSI crack. My system relief is set at 475psi. Why is it running over the R/V on retract???

Not enough information to even make an educated guess.

What is pump rated flow at what RPM?

What is motor RPM?

What is the cylinder diameter?

What is the cylinders rod diameter?

What size are the flow lines to and from the cylinder ports?

What length are the flow lines?

Farmr,
Do I understand correctly that the cylinder extends when the directional valve is shifted to any position other than center?
Maytag

well thanks for the fast response...The cyl ext in one valve pos and ret in the other..But I think that I have figured it out...the pressure is from the flow being too high and adding some back pressure to tthe cercuit...too much flow for the d03 pilot operated c/v's. Good thing it only needs to lift a few hundred pounds so some pressure is left over for work anyways...
thanks.