A gas flow bellows valve (50) includes a self-centering toroidal guide (6) which seals in line contact the main valve body (1) and a bonnet (8), with a valve stem (4) being translatable therein.

To get such flows at lower pressures, a whole different kind of valve is needed, like a pressure compensated valve, a bellow valve.

With a bellow valve, flows of several hundreds of liters per minute can be reached with a minimum pressure difference.