| 摘要 |
<p>A control valve for automatically maintaining a constant rate of flow of a fluid through a pipeline includes a housing having therethrough a passage including an inlet opening and an outlet smaller than the inlet opening. An orifice plate is positioned within the passage adjacent the outlet opening, the orifice plate having therethrough an orifice. A regulating diaphragm is positioned within the passage at a location upstream of the orifice plate. The regulating diaphragm has therethrough circumferential ports and a central opening smaller than the orifice. The regulating diaphragm is formed of an elastic material such that the regulating diaphragm is deflectable toward the orifice plate in response to pressure differences across the control valve between a maximum deflected position, whereat the regulating diaphragm abuts the orifice plates, thereby closing the circumferential ports, and fluid flow is restricted by the central opening, and various positions whereat the regulating diaphragm is spaced from the orifice plate, thereby allowing fluid flow through the circumferential ports.</p> |
