u/InfiniteAd6745

I know this is a loaded question and that there's a lot of variables. I understand some concepts, such as the k factor, bend deduction, bend angle, but once you throw the dies into the mix I get really confused. The shop I work at has whole racks full and I have no clue what the process is to choose one top or bottom die from one another. We do a lot of different kinds of bending, 1/8' to 3/4'' mostly in mild steel, all shapes and sizes, everything from single bends to cones. Thanks!

I know there is information all over the internet on this, but I can't get the concept through my head. I understand that in an open loop system, flow starts and ends in the reservoir. What would an example of this be? Then in a closed loop system, flow starts and ends at the pump? So how is the reservoir being bypassed? If someone can dumb this down for me I would greatly appreciate it. Then to add on to this, can both open loop and closed loop, each be open center and closed center based on the design of the DCV?