Inquiry about pressure vessels 1

[Simon Aku]

Hi everyone!
I am currently working on a technical analysis and need to determine the optimal geometry of a pressure vessel.
The vessel must contain a specific gas volume under pressure (including considerations for a hydraulic test. The test pressure is twice the working pressure). I have the material properties, such as admissible stress, elastic modulus, and Poisson’s ratio, as well as constraints on the vessel’s dimensions. While I have some experience with finite element analysis, I’m not entirely sure how to approach this problem. I understand that ASME codes provide relevant guidelines, but I’m feeling a bit lost on how to get started. Any suggestions, resources, or insights on how to tackle this would be greatly appreciated.
Thanks in advance!

 

[LittleInch]

Optimal geometry?

ASME VIII is the main pressure vessel design code, but you really need to know what you're doing here and why.

ASME VIII has been around for decades and many analysis and design tools exist to design vessels. Really not sure why you want a hydrostatic test double the MAWP??

I'll be honest here - this sounds very dangerous to me and is like someone asking how to design a car, or an engine, or a rocket from first principles. If you're being asked to do "technical analysis" - what is that - on something you don't seem to have the faintest idea about, maybe its time to pass on that one and give it to say a pressure vessel design company to do?

But depending on what exactly the pressure and size is is you can go from a flat end like a flanged connection to a complete doem end / half a sphere to anything in between. Most pressure vessels use tori-spherical or semi elliptical heads which are the most efficient in terms of material and strength.

See e.g. https://www.engineersedge.com/pressure,045vessel/dished_head_formula_13916.htm

 

[TGS4]

The description of your problem sounds very odd. Is this a school/university problem or a real world problem?

My typical suggestion, if this is a real-world problem, is to have your boss hire an expert in the field, and then do your best to learn from them.

BTW - the optimal (however I want to define that word) shape for a pressure vessel is a sphere. But fabricating a sphere, transporting it, supporting it, etc. bring certain challenges. And if your pressure vessel has a size beyond that of a typical desk, then you need to also concern yourself with wind and seismic loads, in addition to the pressure loads. Plus, is your vessel subject to pressure or temperature cycling? What about nozzle loads? Ladder and platforms? If you are going with a cylindrical shape rather than a sphere, will it be oriented horizontally or vertically? How will it be supported? Is it at grade or high in a structure?

 

[TomLee777]

You should first work with your client to determine which ASME code is to be used. ASME Section VIII Division I is a rule-based code, it needs less engineering time but results thicker walls; Division II use rigorous analysis with more certainties, resulting saved materials cost, but engineering cost is higher. Once the code is determined, get familiar with code and strictly follow the code. Pressure is largely based on experience; you'd better retain a experienced PV designer or fabricator to do this.