| 摘要 |
<p>A fluid flow rate control method is provided that uses a flow rate range variable type pressure type flow rate control device provided with at least two or more parallel fluid passages disposed between the downstream side of a control valve of the control device and a fluid supply pipe passage, and orifices having different fluid flow rate characteristics are respectively interposed in parallel fluid passages to pass fluid in a first flow rate region through one orifice for flow rate control, and to pass fluid in a second flow rate region through at least another orifice for flow rate control. Flow rate characteristics of the respective orifices are selected so that a maximum controllable flow rate of fluid in the first flow rate region at low flow rate is smaller than 10% of a maximum controllable flow rate in the second flow rate region at high flow rate.</p> |
