# Is this kind of pressure chamber design possible?

## Main Question or Discussion Point

Hi!
Given that the chamber is airtight and no air leakage occurs, is the design in the picture below possible? Can the pressure inside the chamber cause the button (black part at the top) to be "pushed"?

https://imgur.com/a/wOSD30D

Obviously the temperatures are over-exaggerated, but the principle is the same at very high temperatures.

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sophiecentaur
Gold Member
It's not clear what's going on here. Are you attempting to represent the effects of Convection, caused by the red (=hot?) at the bottom?
If so, the convection currents will indeed exert a force on a horizontal (?) disc at the top. It does require a suspension of disbelief, though because the push rod will also be subject so any difference in pressure between inside and outside. A small cross sectional area of hole but, nonetheless there will be an upwards force which may or may not balance the weight force of all the button and disc. A more reasonable scenario would be to use some balanced lever mechanism to transfer the force to the outside.

Hi!
Given that the chamber is airtight and no air leakage occurs, is the design in the picture below possible? Can the pressure inside the chamber cause the button (black part at the top) to be "pushed"?

https://imgur.com/a/wOSD30D

Obviously the temperatures are over-exaggerated, but the principle is the same at very high temperatures.
No, bad design. Thin neck of button as depicted reduce actuation force as square of neck diameter. It can work, but margin for setting pressure of seal nearly non-existent.

sophiecentaur
Gold Member
No, bad design. Thin neck of button as depicted reduce actuation force as square of neck diameter. It can work, but margin for setting pressure of seal nearly non-existent.
If this is a thought experiment then it should, at least. take account of such things and the design should eliminate their effect; it is perfectly possible to do so.

If this is a thought experiment then it should, at least. take account of such things and the design should eliminate their effect; it is perfectly possible to do so.
How much force is it possible to assert through convection? It must be minimal but is it possible to calculate given a scenario?

sophiecentaur