vacuum tank ends

[bmwr1100gs]

Hi All I have a 1974 bitumen rail wagon tank that I want to convert to a vacuum tank for unloading grease trap trucks. Its half inch wall 12mm and 6'8" (2000mm) diameter and 30' (10000mm) length but has no ends. I have 10mm domed ends quoted at$3200 each which are rated to absolute vacuum. The tank barrel is made in sections that are riveted together.
If I were to use flat plate steel on the ends to try and save some money how thick would it need to be?
I am in Australia. Thanks Terry

 

[JStephen]

You need to contact someone local for the actual design work.

Note that to some extent, the thickness and details are going to depend on the code or standard used.

 

[Duwe6]

Off the top of my head, at 6'-8" and full vac, plan on about 4-inches. Impractical.

Get an engineer to design something proper, like ellipsoidal heads, or flat heads with structural stays. Further, *you* have to define "vacuum". Normal vac setups on tank cars only achieve about 1/2 atmosphere. If you design to 'Full Vac', your heads will be twice as thick as 1/2-atmosphere.