I'm getting out of my league admittedly at this point. But it seems like if you can't get past 110 psi, steady or not, with 3/4" of air behind the preload plate, plus .220 of shim, it seems you have leakage somewhere in the system. Maybe John Kunkel or Cope can chime in on that.

Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.