[klksnow]

I want a chemical reaction that goes to completion at lower pressure, but not at higher pressure.  If the container holding the reactants is depressurized, the products will form.  Maybe some kind of splitting reaction that produces more products than reactants, or more repellent products?  Ideally the necessary pressure is above 1 atm, rxn takes common reactants, relatively safe, stable.

Thanks

[Stepan]

What are you trying to achieve? It is not clear yet.

[klksnow]

I want a self-regulating pressurized container.  When gas is released, I want the remaining gas to spontaneously react, increasing the pressure until the container has returned to the starting pressure.

[Stepan]

OK,

What about
H2CO3 ::equil::H2O + CO2

NiH  Ni + H2

Propane (liq)  Propane (gas)