I am interested to know what is a reasonable maximum working pressure I could expect against the evolution of oxygen and hydrogen when electrolysing a typical water electrolyte.

My aim is to make small quantities of isolated $\ce{H2}$ and $\ce{O2}$ for a hobby hydrogen torch and I am curious how tall I can make the middle branch of the [Hofmann Voltameter](https://en.wikipedia.org/wiki/Hofmann_voltameter) before the back pressure stops the production of new gas. Having a predictable gas pressure would allow me to use the collection spaces for gas storage. I do not like the idea of mixing the gases before the torch nozzle like some brave people do so plan to use two collection volumes.

What parameters would be most likely to effect this pressure, electrolyte makeup, temperature, voltage?

Bonus question, is the pressure of $\ce{H2}$ and $\ce{O2}$ expected to be the same in theory and/or practice?

**EDIT:**  

It looks like there is a [high pressure electrolysis](https://en.wikipedia.org/wiki/High-pressure_electrolysis) process out there that operates at many atmospheres of pressure and has been used to pressurise the gas products. I missed it in my first readings on Wikipedia and further research has confirmed it though information is limited, it seems to be a specialised process usually associated with proton exchange membrane systems I think but I am just hoping to use two metal electrodes.