Watch the New Zealand Video and the Colorado Video, he explains it clearly.
This is simple stuff.
The Quenching Circuit is a 0.015" to 0.025" hole, or smaller, and because of this small passageway and the 19% Ambient Air (mostly Nitrogen) mixed in with the Hydrogen and Oxygen, the Nitrogen simply gets in between the Hydrogen and Oxygen and stops them from burning, they MUST touch each other to burn, and the small passageway simply stops the H from reaching the O because the N gets in the way.
They need to be at least 1/8" and work irregardless of Gas Pressure and Gas Volume.
If you dilute the H and O gas even more, by adding more non-combustible gases, then you can increase the hole size greater than 0.025"