# Is this pressure vessel feasible?

I am intending to construct a small pressure vessel. It needs to be around 7 centimeters in length and width and around 1-2 centimeters in depth. It must be capable of being pressurised to 300 psi with sufficient space to contain a small amount of liquid (say 5cc)

Constraints

• The body of the vessel must be made out of nickel-plated annealed brass.

• The vessel will have a brass cap, held in place with silver solder.

• The cap must be sufficiently thin to be pierced when it is inserted into a receptacle.

Is this design feasible?

• For bonus points, what is the minimum possible weight of such an object? – Richard Sep 24 '15 at 15:12
• you are thinking about a 7x7x2 cm box? – mart Sep 24 '15 at 15:26
• A solder connection may not be strong enough to withstand 300 psi, but I'm not an expert. The big red flag is the word "thin." How thin is thin? 300 psi means a 1 in diameter cap would have about 270 pounds exerted on the rim. If the wall is 1/64 in then the stress is on the order of 10000 psi, or 70 MPa. Brasses have yield strengths between 50 and 200 MPa, depending on composition and processing. What kind of brass does your application require? Why choose brass at all? Edit: goofed up units, but this is intended to give a ballpark idea of stresses – wwarriner Sep 26 '15 at 20:57
• This question is less a design, and more a collection of requirements. To answer the question as is would require generation of a design. As noted by Wasabi and Algo, it would be helpful to see your design first. – wwarriner Sep 26 '15 at 21:06
• Well, here's a start, which might be enough to show you whether your idea is feasible or not. 7 cm = about 2.75 in. A 2.75 in square has area about 7.5 sq in so the pressure force on it will be about 2250 pounds, near enough 1 ton. So, you need to make your little box strong enough to drive one wheel of a 4-ton truck over it without breaking it, and also make it "thin enough to be pierced". Good luck! – alephzero Sep 27 '15 at 21:51