| 摘要 |
<p>A pressure activated flow controller (10) for use with a Joule-Thompson valve (12) having a diaphragm actuator (20) that is located outside a dewar (11), and which is not cooled. The diaphragm actuator limits flow based on gas pressure supplied to the dewar from a gas supply (17), not temperature, and does not impede cooldown of a device coupled to the dewar. The diaphragm actuator comprises a diaphragme (22) and load plate (24) that exert a force to open the Joule-Thompson valve. A wave spring (26) provides a force to close the Joule-Thompson valve, thus balancing the back pressure of the gas supply. The diaphragm actuator is compact, and limits flow based on gas supply pressure, not temperature. The present invention thus uses pressure regulation instead of temperature regulation to achieve flow control.</p> |
