LEGO pumps question!

[roineust]

Hello!

I am looking for the most compact and lightweight LEGO pump structure, that can output at least 12 PSI constant - no need for reverse action (no vacuum needed, only constant pressure).

Could you refer me to such a structure plan?

Do you have any idea, what would be the weight of such a structure? How many pumps would be needed with such a structure, to reach 12PSI?

Thanks!