Bob Engelhardt wrote:

When an hydraulic jack is used in a press, there is very little stored
energy. So if you're pressing something and it's sticking, but suddenly
lets go, nothing happens. But in air over hydraulic, there is a lot of
stored energy. Do you get a "lurch" when something sticks and then lets
go? Or is there something built into the jack to control this? E.g., a
flow-restricting orifice?

Thanks,
Bob

The "stored energy" should never exceed one pump stroke worth of ram
travel, probably about 1/8" max. The air cylinder is just operating a
second small hydraulic piston pump, one pump stroke per air cylinder
stroke.

Pete C.