no problem bbforks,
i actually do stand corrected
your right... the valve in the piston is a flow valve that controls fluid flow in the cylinder and aids in the sequencing of the cylinders. The velocity fuse valve is actually on most systems inside the fitting generally on the outside cylinder right hand side or the first cylinder for the inner channels.
I had to go back and read up on my hydraulics theory of operation on these systems.
Its what happens when you get old, brain goes first hehe ;o)

thanks