Pilot-to-open check valves on the rod side of a cylinder may be a problem because intensification could increase rod side pressure above design limits. Cylinders with large rods may intensify rod end pressure past the point where blind end pressure is enough to pilot the valve open. Use the equations below. For example, the application is a retract-to-clamp cylinder with a blind end area to rod end area ratio of 2:1. Clamping pressure is 2000 psi (140 bar). If the pilot to open check has a pilot ratio of 3:1 it will take more than 2000 psi (140 bar) to pilot the check open and at that point the rod end pressure will have climbed to 6000 psi (420 bar).