摘要 |
This invention provides a flow amount adjustment apparatus able to adjust flow amount with high reliability at a low cost without being oversized. The flow amount adjustment apparatus has a plurality of orifices having different bore diameter for a predetermined flow amount, respectively, the orifices being opened and closed by an open-close member, respectively; a primary piping connected to each of the orifices for supplying gas adjusted to a prescribed pressure; and a secondary piping connected to each of the orifices for gathering gas passed through an opened orifice or a plurality of opened orifices, wherein one orifice or a plurality of orifices capable of satisfying a prescribed flow amount are selected and opened. |