POD - Can't flood the bowl
The construction of POD does not use conventional ball bearings to seal the air or to stop the water backflow through the diffuser when purging. The stainless diffuser door covers the steam entry. It is "normally closed". This allows instantaneous response when purging. The diffuser opening is maximized to allow steam pass-through without much resistance. The steam chamber splits the incoming steam in to two channels that converge and mix with the water prior to contacting the diffuser holes.
The number of diffuser holes was calculated to be proportional to the inlet cross sectional area to prevent restriction and maximized bubble diffusion in the water.