Hello, This is my first post, so I believe, that you understand and help for me. So I have a task to design vacuum vessel, precisely, my task names "Training stand to measure the height of the flight fuel pump". Height will be simulated by vacuum in fuel tank, which will create a vacuum pump. Tank capacity will be about 120 liters. Less inside pressure will be about 23,8 kPa, when outside also be 101 kPa. So, could anyone give me advise how to design fuel tank? (economic materials, light heavy, form, calculating...), that the tank didn't collapsed? Thank you in advance!