How much force is inside the pressure vessel
The thickness or strength of the pressure vessel has no relation to the height or volume of the pressure vessel, and this is not my algorithm, the GB150 algorithm. But considering the pressure vessel pressure test especially after filled with water and after emptying may instantaneous under external pressure, or when volume increases to a certain degree of installation and stability of the pressure vessel, so the volume is not unlimited increase. I hope you can take a serious look at the fixed pressure vessel safety technology supervision procedure and GB150.
Currently, the design of the pressure vessel must be based on the standard gb150-2011. Look at your presentation, your container design pressure is 0.2 MPa, and you want to calculate the thickness of the wall and get 1.5 mm to do the strength check, right? This is the formula for the strength school kernel (it's not easy to type in the letter or the formula here, I'm just saying it in words.) Maximum allowable work pressure = 2 times the effective wall thickness times the material allowable stress times the weld system divided by (internal diameter + wall thickness) In your known condition, only the inner diameter of 500mm and the wall thickness 1.5mm (in fact, GB150, the wall thickness is not less than 3mm) So, you also have to give your material and the maximum working temperature to find out what the allowable stress is, and you have to give your welding coefficients Due to you said is a simple pressure vessels, it is assume that your material is Q245R, normal temperature is used, check GB150, its allowable stress take 147, welded joint coefficient of 0.8, regardless of the thickness of additional quantity, forced by your 1.5 mm is calculated, the allowable stress of the container you P = 2 * 1.5 * 147 * 0.8 / (500 + 1.5) = 0.7 MPa So, even if the 1.5 mm mm, strength is also able to meet the requirements. But not just meet the strength requirement of pressure vessel, but also meet the requirements of stability, and its design and manufacture must conform to the requirements of GB150-2011, so your actual wall thickness should be at least 3 mm. That's all, I hope I can give you a hint.
In an instant, the pressure inside the container is less than the atmospheric pressure, and the vessel is subjected to external pressure, which is unstable
