I designed a very large custom vacuum chamber to test out large circuit breakers and electrical components alike. I believe I designed this to be over kill...however I am having issues remembering what equations are needed to have this work out properly...I feel like I am going around in circles at the moment. The chamber dimensions are 80" x 60" x 90" made out of 1" thick 304 SS. Each side wall has vertical supports that are 1" thick steel that extrude from the surface 5" and are spaced roughly 6-7" center to center from each other so that this large chamber will have minimal deflection. I haven't had to calculate a rectangular vacuum chamber before so I am a little hesitant to believe in my own calculations unfortunately. If anyone can get me started in the right direction so that I know my chamber will not fail I would greatly appreciate it. Needed parameters are: working pressure = 1 atm, designed pressure= 2atm or 32 psi roughly. I am also not sure how to get a proper factor of safety calculation when analyzing this chamber as well...and of course I do not have solid works FEA capabilities at my company....otherwise this would be cake. any help is appreciated! Attached is a screen grab of the chamber.