## Calculate thickness of a pressurized vessel

Hi guys.
I am trying to figure out how thick should be an aluminium pressurized vessel with a internal pressure of 0.125 pa or 1/8 bar. The shape of the box is a cylinder 130cm base x 170cm height. The maximum pressure difference is 0.125 bar inside -> 0 bar outside.
I know that i need to know the joint efficiency of the vessel, but i would estimate that generally.
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 Sorry i made a mistake writing data: Internal pressure: 0.125 bar Minimum external pressure: 0 bar I forgot: The vessel will be made by laser cutted aluminium sheet, welded with TIG technology. Please help.
 I am assuming gauge pressure. So the outside is at normal air pressure and not a vacuum? 0.125 bar might be the operating pressure but what is the maximum permissible pressure? And what do you intend to design to make sure the maximum pressure is not exceeded? If the pressure is absolute (i.e. your 0 bar is actually a vacuum) then you might want to plan for a leak to atmosphere from outside the system and, therefore, a pressure of 1 bar in the vessel. If it will not exceed 0.5 bar then it does not fall in to the EU definition of a Simple Pressure Vessel.