Abstract: A low cost diaphragm actuated absolute pressure regulator. The regulator comprises a housing having first and second sections that are secured together. The first section has a cavity and a diaphragm that seals the cavity and first section of the housing. An O-ring seal is disposed in a groove of the first section that seals against the diaphragm. The second section of the housing houses a movable and sealable vent plug that moves in response to movement of the diaphragm, and one or more vent openings for venting the interior of the second section to external pressure in response to motion of the diaphragm. The pressure regulator may be preferentially used in an upper atmospheric system that needs to maintain a specified pressure, but requires venting capabilities. Such systems include missiles that fly into the upper atmosphere.

Abstract: A pressure activated flow controller for use with a Joule-Thomson valve having a diaphragm actuator that is located outside a dewar, and which is not cooled. The diaphragm actuator limits flow based on gas pressure supplied to the dewar from a gas supply, not temperature, and does not impede cooldown of a device coupled to the dewar. The diaphragm actuator comprises a diaphragm and load plate that exert a force to open the Joule-Thomson valve. A wave spring provides a force to close the Joule-Thomson 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 temperature regulation to achieve flow control.